key bindings - Page 188

Has FreeType been ported to C#?

- by tgiphil

I'm looking for a native implementation of the FreeType library in C#, but not a .NET bindings around the FreeType DLL.

C++ vs Matlab vs Python as a main language for Computer Vision Research

Hi all, Firstly, sorry for a somewhat long question but I think that many people are in the same situation as me and hopefully they can also gain some benefit from this. I'll be starting my PhD very soon which involves the fields of computer vision, pattern recognition and machine learning. Currently, I'm using opencv (2.1) C++ interface and I especially like its powerful Mat class and the overloaded operations available for matrix and image operations and seamless transformations. I've also tried (and implemented many small vision projects) using opencv python interface (new bindings; opencv 2.1) and I really enjoy python's ability to integrate opencv, numpy, scipy and matplotlib. But recently, I went back to opencv C++ interface because I felt that the official python new bindings were not stable enough and no overloaded operations are available for matrices and images, not to mention the lack of machine learning modules and slow speeds in certain operations. I've also used Matlab extensively in the past and although I've used mex files and other means to speed up the program, I just felt that Matlab's performance was inadequate for real-time vision tasks, be it for fast prototyping or not. When the project becomes larger and larger, many tasks have to be re-written in C and compiled into Mex files increasingly and Matlab becomes nothing more than a glue language. Here comes the sub-questions: For carrying out research in these fields (machine learning, vision, pattern recognition), what is your main or ideal programming language for rapid prototyping of ideas and testing algorithms contained in papers? For computer vision research work, can you list down the pros and cons of using the following languages? C++ (with opencv + gsl + svmlib + other libraries) vs Matlab (with all its toolboxes) vs python (with the imcomplete opencv bindings + numpy + scipy + matplotlib). Are there computer vision PhD/postgrad students here who are using only C++ (with all its availabe libraries including opencv) without even needing to resort to Matlab or python? In other words, given the current existing computer vision or machine learning libraries, is C++ alone sufficient for fast prototyping of ideas? If you're currently using Java or C# for your research, can you list down the reasons why they should be used and how they compare to other languages in terms of available libraries? What is the de facto vision/machine learning programming language and its associated libraries used in your research group? Thanks in advance. Edit: As suggested, I've opened the question to both academic and non-academic computer vision/machine learning/pattern recognition researchers and groups.

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Asp.net Custom user control button. How to stop multiple clicks by user.

- by Laurence Burke

I am trying to modify an open source Forum called YetAnotherForum.net in the project they have a custom user control called Yaf:ThemeButton. Now its rendered as an anchor with an onclick method in this code ThemeButton.cs using System; using System.Web.UI; using System.Web.UI.WebControls; namespace YAF.Controls { /// <summary> /// The theme button. /// </summary> public class ThemeButton : BaseControl, IPostBackEventHandler { /// <summary> /// The _click event. /// </summary> protected static object _clickEvent = new object(); /// <summary> /// The _command event. /// </summary> protected static object _commandEvent = new object(); /// <summary> /// The _attribute collection. /// </summary> protected AttributeCollection _attributeCollection; /// <summary> /// The _localized label. /// </summary> protected LocalizedLabel _localizedLabel = new LocalizedLabel(); /// <summary> /// The _theme image. /// </summary> protected ThemeImage _themeImage = new ThemeImage(); /// <summary> /// Initializes a new instance of the <see cref="ThemeButton"/> class. /// </summary> public ThemeButton() : base() { Load += new EventHandler(ThemeButton_Load); this._attributeCollection = new AttributeCollection(ViewState); } /// <summary> /// ThemePage for the optional button image /// </summary> public string ImageThemePage { get { return this._themeImage.ThemePage; } set { this._themeImage.ThemePage = value; } } /// <summary> /// ThemeTag for the optional button image /// </summary> public string ImageThemeTag { get { return this._themeImage.ThemeTag; } set { this._themeImage.ThemeTag = value; } } /// <summary> /// Localized Page for the optional button text /// </summary> public string TextLocalizedPage { get { return this._localizedLabel.LocalizedPage; } set { this._localizedLabel.LocalizedPage = value; } } /// <summary> /// Localized Tag for the optional button text /// </summary> public string TextLocalizedTag { get { return this._localizedLabel.LocalizedTag; } set { this._localizedLabel.LocalizedTag = value; } } /// <summary> /// Defaults to "yafcssbutton" /// </summary> public string CssClass { get { return (ViewState["CssClass"] != null) ? ViewState["CssClass"] as string : "yafcssbutton"; } set { ViewState["CssClass"] = value; } } /// <summary> /// Setting the link property will make this control non-postback. /// </summary> public string NavigateUrl { get { return (ViewState["NavigateUrl"] != null) ? ViewState["NavigateUrl"] as string : string.Empty; } set { ViewState["NavigateUrl"] = value; } } /// <summary> /// Localized Page for the optional link description (title) /// </summary> public string TitleLocalizedPage { get { return (ViewState["TitleLocalizedPage"] != null) ? ViewState["TitleLocalizedPage"] as string : "BUTTON"; } set { ViewState["TitleLocalizedPage"] = value; } } /// <summary> /// Localized Tag for the optional link description (title) /// </summary> public string TitleLocalizedTag { get { return (ViewState["TitleLocalizedTag"] != null) ? ViewState["TitleLocalizedTag"] as string : string.Empty; } set { ViewState["TitleLocalizedTag"] = value; } } /// <summary> /// Non-localized Title for optional link description /// </summary> public string TitleNonLocalized { get { return (ViewState["TitleNonLocalized"] != null) ? ViewState["TitleNonLocalized"] as string : string.Empty; } set { ViewState["TitleNonLocalized"] = value; } } /// <summary> /// Gets Attributes. /// </summary> public AttributeCollection Attributes { get { return this._attributeCollection; } } /// <summary> /// Gets or sets CommandName. /// </summary> public string CommandName { get { if (ViewState["commandName"] != null) { return ViewState["commandName"].ToString(); } return null; } set { ViewState["commandName"] = value; } } /// <summary> /// Gets or sets CommandArgument. /// </summary> public string CommandArgument { get { if (ViewState["commandArgument"] != null) { return ViewState["commandArgument"].ToString(); } return null; } set { ViewState["commandArgument"] = value; } } #region IPostBackEventHandler Members /// <summary> /// The i post back event handler. raise post back event. /// </summary> /// <param name="eventArgument"> /// The event argument. /// </param> void IPostBackEventHandler.RaisePostBackEvent(string eventArgument) { OnCommand(new CommandEventArgs(CommandName, CommandArgument)); OnClick(EventArgs.Empty); } #endregion /// <summary> /// Setup the controls before render /// </summary> /// <param name="sender"> /// </param> /// <param name="e"> /// </param> private void ThemeButton_Load(object sender, EventArgs e) { if (!String.IsNullOrEmpty(this._themeImage.ThemeTag)) { // add the theme image... Controls.Add(this._themeImage); } // render the text if available if (!String.IsNullOrEmpty(this._localizedLabel.LocalizedTag)) { Controls.Add(this._localizedLabel); } } /// <summary> /// The render. /// </summary> /// <param name="output"> /// The output. /// </param> protected override void Render(HtmlTextWriter output) { // get the title... string title = GetLocalizedTitle(); output.BeginRender(); output.WriteBeginTag("a"); output.WriteAttribute("id", ClientID); if (!String.IsNullOrEmpty(CssClass)) { output.WriteAttribute("class", CssClass); } if (!String.IsNullOrEmpty(title)) { output.WriteAttribute("title", title); } else if (!String.IsNullOrEmpty(TitleNonLocalized)) { output.WriteAttribute("title", TitleNonLocalized); } if (!String.IsNullOrEmpty(NavigateUrl)) { output.WriteAttribute("href", NavigateUrl.Replace("&", "&")); } else { // string.Format("javascript:__doPostBack('{0}','{1}')",this.ClientID,"")); output.WriteAttribute("href", Page.ClientScript.GetPostBackClientHyperlink(this, string.Empty)); } bool wroteOnClick = false; // handle additional attributes (if any) if (this._attributeCollection.Count > 0) { // add attributes... foreach (string key in this._attributeCollection.Keys) { // get the attribute and write it... if (key.ToLower() == "onclick") { // special handling... add to it... output.WriteAttribute(key, string.Format("{0};{1}", this._attributeCollection[key], "this.blur();this.display='none';")); wroteOnClick = true; } else if (key.ToLower().StartsWith("on") || key.ToLower() == "rel" || key.ToLower() == "target") { // only write javascript attributes -- and a few other attributes... output.WriteAttribute(key, this._attributeCollection[key]); } } } // IE fix if (!wroteOnClick) { output.WriteAttribute("onclick", "this.blur();this.style.display='none';"); } output.Write(HtmlTextWriter.TagRightChar); output.WriteBeginTag("span"); output.Write(HtmlTextWriter.TagRightChar); // render the optional controls (if any) base.Render(output); output.WriteEndTag("span"); output.WriteEndTag("a"); output.EndRender(); } /// <summary> /// The get localized title. /// </summary> /// <returns> /// The get localized title. /// </returns> protected string GetLocalizedTitle() { if (Site != null && Site.DesignMode == true && !String.IsNullOrEmpty(TitleLocalizedTag)) { return String.Format("[TITLE:{0}]", TitleLocalizedTag); } else if (!String.IsNullOrEmpty(TitleLocalizedPage) && !String.IsNullOrEmpty(TitleLocalizedTag)) { return PageContext.Localization.GetText(TitleLocalizedPage, TitleLocalizedTag); } else if (!String.IsNullOrEmpty(TitleLocalizedTag)) { return PageContext.Localization.GetText(TitleLocalizedTag); } return null; } /// <summary> /// The on click. /// </summary> /// <param name="e"> /// The e. /// </param> protected virtual void OnClick(EventArgs e) { var handler = (EventHandler) Events[_clickEvent]; if (handler != null) { handler(this, e); } } /// <summary> /// The on command. /// </summary> /// <param name="e"> /// The e. /// </param> protected virtual void OnCommand(CommandEventArgs e) { var handler = (CommandEventHandler) Events[_commandEvent]; if (handler != null) { handler(this, e); } RaiseBubbleEvent(this, e); } /// <summary> /// The click. /// </summary> public event EventHandler Click { add { Events.AddHandler(_clickEvent, value); } remove { Events.RemoveHandler(_clickEvent, value); } } /// <summary> /// The command. /// </summary> public event CommandEventHandler Command { add { Events.AddHandler(_commandEvent, value); } remove { Events.RemoveHandler(_commandEvent, value); } } } } now that is just cs file its handled like this in the .ascx page of the actual website <YAF:ThemeButton ID="Save" runat="server" CssClass="yafcssbigbutton leftItem" TextLocalizedTag="SAVE" OnClick="Save_Click" /> now it is given an OnClick codebehind function that does some serverside function like this protected void Save_Click(object sender, EventArgs e) { //some serverside code here } now I have a problem with the user being able to click multiple times and firing that serverside function multiple times. I have added in the code as of right now an extra onclick="this.style.display='none'" in the .cs code but that is a ugly fix I was wondering if anyone would have a better idea of disabling the ThemeButton clientside?? pls any feedback if I need to give more examples or further explain the question thanks.

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WPF Custom ListBox as Buttons Click not firing

- by Ryan

I am attempting to have a ListBox of TextBoxes with click events. I have read that one way to achieve this was to have a list of Buttons and call ButtonBase.Click="" on the ListBox. This was not working. Any advice as to how I would hook up a click event to the listbox items? Thanks <Window.Resources> <ControlTemplate x:Key="MouseOverFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF013B73" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF014A8F" Offset="0.5"/> <GradientStop Color="#FF003363" Offset="1"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="MouseOverFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource MouseOverFocusTemplate}"/> </Style> <ControlTemplate x:Key="LostFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="LostFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource LostFocusTemplate}"/> </Style> <ControlTemplate x:Key="GotFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FFE38E27" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="Black" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF002F5C" Offset="0.5"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="GotFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource GotFocusTemplate}"/> </Style> <Style TargetType="{x:Type Button}" x:Key="listButton"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="Button"> <Border BorderBrush="Black" BorderThickness="1" Margin="-2,0,0,-1"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Grid.RenderTransform>  <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" Style="{StaticResource LostFocusStyle}" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" Name="bar" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </Border> <ControlTemplate.Triggers> <Trigger Property="IsMouseOver" Value="true"> <Setter TargetName="bar" Property="Style" Value="{StaticResource MouseOverFocusStyle}" /> </Trigger> </ControlTemplate.Triggers> </ControlTemplate> </Setter.Value> </Setter> </Style> <DataTemplate x:Key="CustomListData" DataType="{x:Type ListBoxItem}"> <Button Style="{StaticResource listButton}" /> </DataTemplate> </Window.Resources> <Window.DataContext> <ObjectDataProvider ObjectType="{x:Type local:ImageLoader}" MethodName="LoadImages" /> </Window.DataContext> <ListBox ItemsSource="{Binding}" Width="320" Background="#FF021422" BorderBrush="#FF1C4B79"> <ListBox.Resources> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}">Transparent</SolidColorBrush> <Style TargetType="{x:Type ListBox}"> <Setter Property="ItemTemplate" Value="{StaticResource CustomListData }" /> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" /> </Style> </ListBox.Resources> </ListBox>

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Integrating Jython Cpython

- by eric.frederich

I am about to begin a project where I will likely use PyQt or Pyside. I will need to interface with a buggy 3rd party piece of server software that provides C++ and Java APIs. The Java APIs are a lot easier to use because you get Exceptions where with the C++ libraries you get segfaults. Also, the Python bindings to the Java APIs are automatic with Jython whereas the Python bindings for the C++ APIs don't exist. So, how would a CPython PyQt client application be able to communicate with these Java APIs? How would you go about it? Would you have another separate Java process on the client that serializes / pickles objects and communicates with the PyQt process over a socket? I don't want to re-invent the wheel... is there some sort of standard interface for these types of things? Some technology I should look into? RPC, Corba, etc? Thanks, ~Eric

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Installing GDAL for Python

- by Nate

I am trying to install GDAL for python on a Windows XP machine (Python 2.6 currently installed) following the instructions at http://trac.osgeo.org/gdal/wiki/GdalOgrInPython (as is mirrored in a hundred other places). It says I need both the GDAL source (or Windows binary) and the python bindings. The python binding are be downloaded from the python cheeseshop (http://pypi.python.org/pypi/Python_GDAL/1.3.1). I don't see a download link on this page nor can I locate the python binding elsewhere - all instruction I can find seem to point to the same cheeseshop page. This seems like I'm either missing something embarrassingly simple or the bindings file has disappeared. Any thoughts on which it is? Thanks.

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WCF. BasicHttpBinding Certificates.

- by Andrew Kalashnikov

Hello colleagues. I've got some problems. I've created WCF service with basicHttpBinding and hosted by IIS 6.0. <system.serviceModel> <bindings> <basicHttpBinding> <binding name="BindingConfiguration1" maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647"> <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647"/> <security mode="Transport"> <transport clientCredentialType="None" /> </security> </binding> </basicHttpBinding> </bindings> <services> <service name="RegistratorService.Registrator" behaviorConfiguration="RegistratorService.Service1Behavior"> <endpoint address="" binding="basicHttpBinding" contract="RegistratorService.IRegistrator" bindingConfiguration="BindingConfiguration1"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="mex" binding="mexHttpsBinding" contract="IMetadataExchange"/> </service> </services> <behaviors> <serviceBehaviors> <behavior name="RegistratorService.Service1Behavior"> <serviceCredentials> <clientCertificate> <authentication certificateValidationMode="PeerOrChainTrust" revocationMode="NoCheck"/> </clientCertificate> <serviceCertificate storeLocation="LocalMachine" storeName="My" findValue="CN=Server" /> </serviceCredentials> <serviceMetadata httpsGetEnabled="true" /> <serviceDebug includeExceptionDetailInFaults="true" /> </behavior> </serviceBehaviors> </behaviors> Also I have cert authority on this server and I issue certs for server and client. I server cert at server and client cert at client. When I try consume service from client I get famous: "Could not establish trust relationship for the SSL/TLS secure channel with authority" All sites recommend override ServicePointManager.ServerCertificateValidationCallback by set return value to true. Bu I want decide this issue other right way. My client config: <system.serviceModel> <behaviors> <endpointBehaviors> <behavior name="ClientBehavior"> <clientCredentials> <serviceCertificate> <authentication certificateValidationMode="ChainTrust" revocationMode="NoCheck"/> </serviceCertificate> <clientCertificate findValue="CN=PharmPortal" storeLocation="LocalMachine" storeName="My"/> </clientCredentials> </behavior> </endpointBehaviors> </behaviors> <bindings> <basicHttpBinding> <binding name="BasicHttpBinding_IRegistrator" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered" useDefaultWebProxy="true"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <security mode="Transport"> <transport clientCredentialType="None" proxyCredentialType="None" realm="" /> </security> </binding> </basicHttpBinding> </bindings> <client > <endpoint address="https://aurit-server2/Registrator.svc" binding="basicHttpBinding" behaviorConfiguration="ClientBehavior" bindingConfiguration="BasicHttpBinding_IRegistrator" contract="ServiceReference1.IRegistrator" name="BasicHttpBinding_IRegistrator" > <identity> <dns value="Server" /> </identity> </endpoint> </client> </system.serviceModel> I set up client certificate. Why i get error?

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Duplex communication using NetTcpBinding - ContractFilter mismatch?

- by Shaul

I'm making slow and steady progress towards having a duplex communication channel open between a client and a server, using NetTcpBinding. (FYI, you can observe my newbie progress here and here!) I'm now at the stage where I have successfully connected to my server, through the server's firewall, and the client can make requests of the server. In the other direction, however, things aren't quite so happy. It works fine when testing on my own machine, but when testing over the internet, when I try to initiate a callback from the server side, I get an error: The message with Action 'http://MyWebService/IWebService/HelloWorld' cannot be processed at the receiver, due to a ContractFilter mismatch at the EndpointDispatcher. This may be because of either a contract mismatch (mismatched Actions between sender and receiver) or a binding/security mismatch between the sender and the receiver. Check that sender and receiver have the same contract and the same binding (including security requirements, e.g. Message, Transport, None). Here are some of the key bits of code. First, the web interface: [ServiceContract(Namespace = "http://MyWebService", SessionMode = SessionMode.Required, CallbackContract = typeof(ISiteServiceExternal))] public interface IWebService { [OperationContract] void Register(long customerID); } public interface ISiteServiceExternal { [OperationContract] string HelloWorld(); } Then, on the client side (I was fiddling with these attributes without really knowing what I'm doing): [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession, Namespace="http://MyWebService")] class SiteServer : IWebServiceCallback { string IWebServiceCallback.HelloWorld() { return "Hello World!"; } ... } So what am I doing wrong here? EDIT: Adding app.config code. From server: <system.serviceModel> <diagnostics> <messageLogging logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" logEntireMessage="true" maxMessagesToLog="1000" maxSizeOfMessageToLog="524288" /> </diagnostics> <behaviors> <serviceBehaviors> <behavior name="mex"> <serviceDebug includeExceptionDetailInFaults="true"/> <serviceMetadata/> </behavior> </serviceBehaviors> </behaviors> <services> <service name ="MyWebService.WebService" behaviorConfiguration="mex"> <endpoint address="net.tcp://localhost:8000" binding="netTcpBinding" contract="MyWebService.IWebService" bindingConfiguration="TestBinding" name="MyEndPoint"></endpoint> <endpoint address ="mex" binding="mexTcpBinding" name="MEX" contract="IMetadataExchange"/> <host> <baseAddresses> <add baseAddress="net.tcp://localhost:8000"/> </baseAddresses> </host> </service> </services> <bindings> <netTcpBinding> <binding name="TestBinding" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" portSharingEnabled="false"> <readerQuotas maxDepth="32" maxStringContentLength ="8192" maxArrayLength ="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384"/> <security mode="None"/> </binding> </netTcpBinding> </bindings> </system.serviceModel> and on the client side: <system.serviceModel> <bindings> <netTcpBinding> <binding name="MyEndPoint" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" transactionFlow="false" transferMode="Buffered" transactionProtocol="OleTransactions" hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxBufferPoolSize="524288" maxBufferSize="65536" maxConnections="10" maxReceivedMessageSize="65536"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" /> <security mode="None"> <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign"> <extendedProtectionPolicy policyEnforcement="Never" /> </transport> <message clientCredentialType="Windows" /> </security> </binding> </netTcpBinding> </bindings> <client> <endpoint address="net.tcp://mydomain.gotdns.com:8000/" binding="netTcpBinding" bindingConfiguration="MyEndPoint" contract="IWebService" name="MyEndPoint" /> </client> </system.serviceModel>

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How do I merge a local branch into TFS

- by Johnny

hi, I did a stupid thing and branched my project on my local disk instead of doing it on the TFS. So now I have two projects on my disk: the old one which has TFS bindings and the new, which doesn't. I want to merge those changes back into the TFS project. How would I go about doing that? I can't do Compare because my local branch has no TFS bindings. There should be some way to compare the differences between the two projects locally and then meld the differences into the old project and check-in, but I can't find an easy way of doing that. Any other solutions?

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WCF service under https environment

- by Budda

I've created and tested WCF service, everything works fine. When I deployed to TEST environment and tried to open https://my.site/myapp/EnrollmentService.svc I've got the error message: Could not find a base address that matches scheme http for the endpoint with binding MetadataExchangeHttpBinding. Registered base address schemes are [https]. Internet showed me that I need to add some more configuration options: http://www.codeproject.com/KB/WCF/7stepsWCF.aspx I've added some settings to service web.config file. Now it looks like in the following way: <system.serviceModel> <services> <service name="McActivationApp.EnrollmentService" behaviorConfiguration="McActivationApp.EnrollmentServicBehavior"> <endpoint address="https://my.site/myapp/EnrollmentService.svc" binding="basicHttpBinding" bindingConfiguration="TransportSecurity" contract="McActivationApp.IEnrollmentService"/> <endpoint address="mex" binding="mexHttpBinding" contract="McActivationApp.IEnrollmentService" /> </service> </services> <behaviors> <serviceBehaviors> <behavior name="McActivationApp.EnrollmentServicBehavior"> <serviceMetadata httpGetEnabled="True"/> <serviceDebug includeExceptionDetailInFaults="False" /> </behavior> </serviceBehaviors> </behaviors> <bindings> <basicHttpBinding> <binding name="TransportSecurity"> <security mode="Transport"> <transport clientCredentialType="None" /> </security> </binding> </basicHttpBinding> </bindings> <serviceHostingEnvironment aspNetCompatibilityEnabled="true" /> </system.serviceModel> Actually, I've added "bindings" section and specified it for my endpoint. But this changed nothing... Please advise, what I need to do. Thanks a lot! P.S. Are there any differences in WCF service consuming from https and http resources?

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comprehensive beginner's tutorial for python and sqlite?

- by Jeremiah Rose

looking for a good tutorial for learning sqlite in python- with a focus on the sql, not the bindings

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Object database for .NET

- by Manga Lee

Are there any object databases for .NET or with bindings for .NET?

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WCF Authentication on the Internet - HELP

- by Eddie

I have a WCF service using the basicHTTP binding. The service will be targeted to be deployed in production in a DMZ environment on a Windows Server 2008 64 bit running IIS 7.0 and is not in an Active Directory domain. The service will be accessed by a business partner over the Internet with SSL protection. Originally, I had built the service to use x.509 Message authentication with wsHTTPBinding and after a lot of problems I punted and decided to back up and use basicHTTP with UserName authentication. Result: same exact, obscure error message as I received with certificate mode. The service works perfectly inside our domain with the exact same authentication but as soon as I move it to the DMZ I get an error reading: "An unsecured or incorrectly secured fault was received from the other party. See the inner FaultException for the fault code and detail". The inner exception message is: "An error occurred when verifying security for the message." The services' web config with binding configuration is as follows: <services> <service behaviorConfiguration="HSSanoviaFacade.Service1Behavior" name="HSSanoviaFacade.HSSanoviaFacade"> <endpoint address="" binding="basicHttpBinding" contract="HSSanoviaFacade.IHSSanoviaFacade" bindingConfiguration="basicHttp"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="mex" binding="mexHttpsBinding" contract="IMetadataExchange" /> <host> <baseAddresses> <add baseAddress="https://FULLY QUALIFIED HOST NAME CHANGED TO PROTECT/> </baseAddresses> </host> </service> </services> <bindings> <basicHttpBinding> <binding name="basicHttp"> <security mode="TransportWithMessageCredential"> <message clientCredentialType="UserName" /> </security> </binding> </basicHttpBinding> </bindings> <behaviors> <serviceBehaviors> <behavior name="HSSanoviaFacade.Service1Behavior"> <serviceMetadata httpsGetEnabled="True" /> <serviceDebug includeExceptionDetailInFaults="True" /> </behavior> </serviceBehaviors> </behaviors> The test client's configuration that gets the error: <bindings> <basicHttpBinding> <binding name="BasicHttpBinding_IHSSanoviaFacade" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered" useDefaultWebProxy="true"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <security mode="TransportWithMessageCredential"> <transport clientCredentialType="None" proxyCredentialType="None" realm="" /> <message clientCredentialType="UserName" algorithmSuite="Default" /> </security> </binding> </basicHttpBinding> </bindings> <client> <endpoint address="https://HOST NAME CHANGED TO PROTECT" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IHSSanoviaFacade" contract="MembersService.IHSSanoviaFacade" name="BasicHttpBinding_IHSSanoviaFacade" /> </client> As mentioned earlier, the service works perfectly on the domain and the production IIS box is not on a domain. I have been tweaking and pulling my hair out for 2 weeks now and nothing seems to work. If anyone can help I would appreciate it. Even a recommendation for a work around for authentication. I'd rather not use a custom authentication scheme but use built-in SOAP capabilities. The credentials pass in thru the proxy i.e. proxy.ClientCredentials.UserName.UserName and proxy.ClientCredentials.UserName.Password are valid accounts on both the internal domain in the test environment and as a machine account on the DMZ IIS box.

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Python/C "defs" file - what is it?

- by detly

In the nautilus-python bindings, there is a file "nautilus.defs". It contains stanzas like (define-interface MenuProvider (in-module "Nautilus") (c-name "NautilusMenuProvider") (gtype-id "NAUTILUS_TYPE_MENU_PROVIDER") ) or (define-method get_mime_type (of-object "NautilusFileInfo") (c-name "nautilus_file_info_get_mime_type") (return-type "char*") ) Now I can see what most of these do (eg. that last one means that I can call the method "get_mime_type" on a "FileInfo" object). But I'd like to know: what is this file, exactly (ie. what do I search the web for to find out more info)? Is it a common thing to find in Python/C bindings? What is the format, and where is it documented? What program actually processes it? (So far, I've managed to glean that it gets transformed into a C source file, and it looks a bit like lisp to me.)

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Emacs cheat sheet that lists equivalents to everyday vim commands

- by Yktula

There were two things that I want to know how to do in Emacs (23.2, *nix): Go to the first character after indentation in a line Go to the first character that's the equivalent to a given character (an equivalent to vim's fx command that goes forward until it hits the x character; maybe C-s (incremental search) is the best way to do this) But, I think it would be better if I had a cheat sheet that listed navigational bindings. Maybe Emacs (self-documenting) can do this on it's own. Is there a list of commands that are equivalent to vim's default commands anywhere? How about a list of navigational key-bindings in Emacs?

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WCF client using basic HTTP authentication

- by AZ

I'm trying to connect to a service that uses basic HTTP authentication. I've configured my binding like this <bindings> <basicHttpBinding> <binding name ="binding"> <security mode="TransportCredentialOnly"> <transport clientCredentialType="Basic"/> </security> </binding> </basicHttpBinding> </bindings> and i'm setting the credentials like this: client.ClientCredentials.UserName.UserName = Settings.UserName; client.ClientCredentials.UserName.Password = Settings.Password; Sill when i make a request i get a "The HTTP request is unauthorized with client authentication scheme 'Basic'" fault back. What am i doing wrong? (i don't have control over the service so all solutions must relate to the client configuration)

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ghc can't find my cabal installed packages

- by nont

I've installed ghc 6.12.3, and then the Haskell Platform. I'm trying to compile a test program: $ ghc test.hs test.hs:3:0: Failed to load interface for `Bindings': Use -v to see a list of the files searched for. so, naturally, I do cabal install Bindings Which works fine, and places the package in ~/.cabal/lib/bindings-0.1.2 The problem is, that when I go to compile again with ghc, it still doesn't find the package I've installed with cabal. compiling in verbose mode gives: ghc -v test.hs Using binary package database: /home/ludflu/ghc/lib/ghc-6.12.3/package.conf.d/package.cache Using binary package database: /home/ludflu/.ghc/x86_64-linux 6.12.3/package.conf.d/package.cache As suggested by another stackoverflow user, I tried: ghc-pkg describe rts > rts.pkg vi rts.pkg # add the /home/ludflu/.cabal/lib to `library-dirs` field ghc-pkg update rts.pkg But to no avail. How to I add the .cabal to the list of package directories to search? Thank you!

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WCF Service error received when using TCP: "The message could not be dispatched..."

- by StM

I am new to creating WCF services. I have created a WCF web service in VS2008 that is running on IIS 7. When I use http the service works perfectly. When I configure the service for TCP and run I get the following error message. There was a communication problem. The message could not be dispatched because the service at the endpoint address 'net:tcp://elec:9090/CoordinateIdTool_Tcp/IdToolService.svc is unavailable for the protocol of the address. I have searched a lot of forums, including this one, for a resolution but nothing has worked. Everything appears to be set up correctly on IIS 7. WAS has been set up to run. The default web site has a net.tcp binding and the application has net.tcp under the enabled protocols. I am including what I think is the important part of the web.config from the host project and also the app.config from the client project I am using to test the service. Hopefully someone can spot my error. Thanks in advance for any help or recommendations that anyone can provide. Web.Config <bindings> <wsHttpBinding> <binding name="wsHttpBindingNoMsgs"> <security mode="None" /> </binding> </wsHttpBinding> </bindings> <services> <service behaviorConfiguration="CogIDServiceHost.ServiceBehavior" name="CogIDServiceLibrary.CogIdService"> <endpoint address="" binding="wsHttpBinding" bindingConfiguration="wsHttpBindingNoMsgs" contract="CogIDServiceLibrary.CogIdTool"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="mex" binding="mexHttpBinding" bindingConfiguration="" contract="IMetadataExchange" /> <endpoint name="CoordinateIdService_TCP" address="net.tcp://elec:9090/CoordinateIdTool_Tcp/IdToolService.svc" binding="netTcpBinding" bindingConfiguration="" contract="CogIDServiceLibrary.CogIdTool"> <identity> <dns value="localhost" /> </identity> </endpoint> </service> </services> <behaviors> <serviceBehaviors> <behavior name="CogIDServiceHost.ServiceBehavior"> <serviceMetadata httpGetEnabled="true" /> <serviceDebug includeExceptionDetailInFaults="false" /> </behavior> </serviceBehaviors> </behaviors> App.Config <system.serviceModel> <diagnostics performanceCounters="Off"> <messageLogging logEntireMessage="true" logMalformedMessages="false" logMessagesAtServiceLevel="false" logMessagesAtTransportLevel="false" /> </diagnostics> <behaviors /> <bindings> <wsHttpBinding> <binding name="WSHttpBinding_CogIdTool" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true" allowCookies="false"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" /> <security mode="None"> <transport clientCredentialType="Windows" proxyCredentialType="None" realm="" /> <message clientCredentialType="Windows" negotiateServiceCredential="true" establishSecurityContext="true" /> </security> </binding> <binding name="wsHttpBindingNoMsg"> <security mode="None"> <transport clientCredentialType="Windows" /> <message clientCredentialType="Windows" /> </security> </binding> </wsHttpBinding> </bindings> <client> <endpoint address="http://sdet/CogId_WCF/IdToolService.svc" binding="wsHttpBinding" bindingConfiguration="wsHttpBindingNoMsg" contract="CogIdServiceReference.CogIdTool" name="IISHostWsHttpBinding"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="http://localhost:1890/IdToolService.svc" binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_CogIdTool" contract="CogIdServiceReference.CogIdTool" name="WSHttpBinding_CogIdTool"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="http://elec/CoordinateIdTool/IdToolService.svc" binding="wsHttpBinding" bindingConfiguration="wsHttpBindingNoMsg" contract="CogIdServiceReference.CogIdTool" name="IIS7HostWsHttpBinding_Elec"> <identity> <dns value="localhost" /> </identity> </endpoint> <endpoint address="net.tcp://elec:9090/CoordinateIdTool_Tcp/IdToolService.svc" binding="netTcpBinding" bindingConfiguration="" contract="CogIdServiceReference.CogIdTool" name="IIS7HostTcpBinding_Elec" > <identity> <dns value="localhost"/> </identity> </endpoint> </client> </system.serviceModel>

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How to? WCF customBinding over Https

- by user663414

Hi all, I'm trying to setup a WCF service for internal use, on our external facing web-farm (we dont have a web farm internally, and I need this service to have failover and load-balancing). Requirements: PerSession state, as we need the service to retain variable data for each session. HTTPS. After lots of googling i've read I needed to create a customBinding, which I've done, but not sure if it is correct. Larger message size, as one of the parameters is a byte[] array, which can be a max of 5mb. no requirement to manually edit the client-side app.config. ie, I need the Developer to just add the service reference, and then starts using the object without fiddly changing of app.config. Note: I've previously had this service working under HTTP correctly (using wsHttpBinding). I've also had it working under HTTPS, but it didn't support PerSession state, and lost internal variable values each function call. I'm currently getting this error from the test harness: Could not find default endpoint element that references contract 'AppMonitor.IAppMonitorWcfService' in the ServiceModel client configuration section. This might be because no configuration file was found for your application, or because no endpoint element matching this contract could be found in the client element. NOTE: The error is arising on an Test Harness EXE, that has the WCF service referenced directly under Service References. This is not the problem of an exe referencing another object, that then references the WCF service, that i've read about. The WSDL is showing correctly when browsing to the URL. Web.Config: <system.serviceModel> <services> <service name="AppMonitor.AppMonitorWcfService" behaviorConfiguration="ServiceBehavior"> <endpoint address="" binding="customBinding" bindingConfiguration="EnablePerSessionUnderHttps" contract="AppMonitor.IAppMonitorWcfService"/> <endpoint address="mex" binding="mexHttpsBinding" contract="IMetadataExchange" /> </service> </services> <bindings> <customBinding> <binding name="EnablePerSessionUnderHttps" maxReceivedMessageSize="5242880"> <reliableSession ordered="true"/> <textMessageEncoding> <readerQuotas maxDepth="64" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> </textMessageEncoding> <httpsTransport authenticationScheme="Anonymous" requireClientCertificate="false"/> </binding> </customBinding> </bindings> <behaviors> <serviceBehaviors> <behavior name="ServiceBehavior"> <serviceMetadata httpsGetEnabled="true" httpGetEnabled="false"/> <serviceDebug includeExceptionDetailInFaults="true"/> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> EXE's App.config (auto-generated when adding the Service Reference): <configuration> <system.serviceModel> <bindings> <wsHttpBinding> <binding name="CustomBinding_IAppMonitorWcfService" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true" allowCookies="false"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="true" /> <security mode="Transport"> <transport clientCredentialType="None" proxyCredentialType="None" realm="" /> <message clientCredentialType="Windows" negotiateServiceCredential="true" establishSecurityContext="true" /> </security> </binding> </wsHttpBinding> </bindings> <client /> </system.serviceModel> </configuration> I'm not sure why the app.config is showing wsHttpBinding? Shouldn't this be customBinding? I really dont want to have to edit the app.config, as this service will be used by dozens of developers, and I want them to just be able to add the Service Reference, and away they go... Using VS2008, .NET 3.51. I think server is IIS7, Win Server 2008, can confirm if needed.

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Programmatic binding of accelerators in wxPython

- by Inductiveload

I am trying to programmatically create and bind a table of accelerators in wxPython in a loop so that I don't need to worry about getting and assigning new IDs to each accelerators (and with a view to inhaling the handler list from some external resource, rather than hard-coding them). I also pass in some arguments to the handler via a lambda since a lot of my handlers will be the same but with different parameters (move, zoom, etc). The class is subclassed from wx.Frame and setup_accelerators() is called during initialisation. def setup_accelerators(self): bindings = [ (wx.ACCEL_CTRL, wx.WXK_UP, self.on_move, 'up'), (wx.ACCEL_CTRL, wx.WXK_DOWN, self.on_move, 'down'), (wx.ACCEL_CTRL, wx.WXK_LEFT, self.on_move, 'left'), (wx.ACCEL_CTRL, wx.WXK_RIGHT, self.on_move, 'right'), ] accelEntries = [] for binding in bindings: eventId = wx.NewId() accelEntries.append( (binding[0], binding[1], eventId) ) self.Bind(wx.EVT_MENU, lambda event: binding[2](event, binding[3]), id=eventId) accelTable = wx.AcceleratorTable(accelEntries) self.SetAcceleratorTable(accelTable) def on_move(self, e, direction): print direction However, this appears to bind all the accelerators to the last entry, so that Ctrl+Up prints "right", as do all the other three. How to correctly bind multiple handlers in this way?

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IIS7: How to bind SSL Certificate to Https Host Header?

- by h3n

I have the following Web Farm: 1. http: mydomain1.com port: 80 2. http: mydomain2.com port: 80 3. https: port: 443 SSL Certificate: myCertificate In II7 when you select https binding, the host name will be disabled. I used the appcmd to bind the host name "admin.mydomain2.com" to the website. appcmd set site /site.name:"admin" /+bindings.[protocol='https',bindingInformation='*:443:admin.mydomain2.com'] A new item was added to the bindings. 3. a. https: port: 443 SSL Certificate: myCertificate b. https: admin.mydomain2.com port:443 SSL Certificate: None If for example I want to remove the first item (a), is it possible to assign a certificate to the second binding (b)?

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SQL Monitor’s data repository: Alerts

- by Chris Lambrou

In my previous post, I introduced the SQL Monitor data repository, and described how the monitored objects are stored in a hierarchy in the data schema, in a series of tables with a _Keys suffix. In this post I had planned to describe how the actual data for the monitored objects is stored in corresponding tables with _StableSamples and _UnstableSamples suffixes. However, I’m going to postpone that until my next post, as I’ve had a request from a SQL Monitor user to explain how alerts are stored. In the SQL Monitor data repository, alerts are stored in tables belonging to the alert schema, which contains the following five tables: alert.Alert alert.Alert_Cleared alert.Alert_Comment alert.Alert_Severity alert.Alert_Type In this post, I’m only going to cover the alert.Alert and alert.Alert_Type tables. I may cover the other three tables in a later post. The most important table in this schema is alert.Alert, as each row in this table corresponds to a single alert. So let’s have a look at it. SELECT TOP 100 AlertId, AlertType, TargetObject, [Read], SubType FROM alert.Alert ORDER BY AlertId DESC; AlertIdAlertTypeTargetObjectReadSubType 165550397:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,9:SqlServer,1,4:Name,s0:,10 265549387:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,7:Machine,1,4:Name,s0:,10 365548187:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 465547157:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 565546147:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 665545187:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 765544157:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 865543147:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 965542187:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 1065541147:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 11… So what are we seeing here, then? Well, AlertId is an auto-incrementing identity column, so ORDER BY AlertId DESC ensures that we see the most recent alerts first. AlertType indicates the type of each alert, such as Job failed (6), Backup overdue (14) or Long-running query (12). The TargetObject column indicates which monitored object the alert is associated with. The Read column acts as a flag to indicate whether or not the alert has been read. And finally the SubType column is used in the case of a Custom metric (40) alert, to indicate which custom metric the alert pertains to. Okay, now lets look at some of those columns in more detail. The AlertType column is an easy one to start with, and it brings use nicely to the next table, data.Alert_Type. Let’s have a look at what’s in this table: SELECT AlertType, Event, Monitoring, Name, Description FROM alert.Alert_Type ORDER BY AlertType; AlertTypeEventMonitoringNameDescription 1100Processor utilizationProcessor utilization (CPU) on a host machine stays above a threshold percentage for longer than a specified duration 2210SQL Server error log entryAn error is written to the SQL Server error log with a severity level above a specified value. 3310Cluster failoverThe active cluster node fails, causing the SQL Server instance to switch nodes. 4410DeadlockSQL deadlock occurs. 5500Processor under-utilizationProcessor utilization (CPU) on a host machine remains below a threshold percentage for longer than a specified duration 6610Job failedA job does not complete successfully (the job returns an error code). 7700Machine unreachableHost machine (Windows server) cannot be contacted on the network. 8800SQL Server instance unreachableThe SQL Server instance is not running or cannot be contacted on the network. 9900Disk spaceDisk space used on a logical disk drive is above a defined threshold for longer than a specified duration. 101000Physical memoryPhysical memory (RAM) used on the host machine stays above a threshold percentage for longer than a specified duration. 111100Blocked processSQL process is blocked for longer than a specified duration. 121200Long-running queryA SQL query runs for longer than a specified duration. 131400Backup overdueNo full backup exists, or the last full backup is older than a specified time. 141500Log backup overdueNo log backup exists, or the last log backup is older than a specified time. 151600Database unavailableDatabase changes from Online to any other state. 161700Page verificationTorn Page Detection or Page Checksum is not enabled for a database. 171800Integrity check overdueNo entry for an integrity check (DBCC DBINFO returns no date for dbi_dbccLastKnownGood field), or the last check is older than a specified time. 181900Fragmented indexesFragmentation level of one or more indexes is above a threshold percentage. 192400Job duration unusualThe duration of a SQL job duration deviates from its baseline duration by more than a threshold percentage. 202501Clock skewSystem clock time on the Base Monitor computer differs from the system clock time on a monitored SQL Server host machine by a specified number of seconds. 212700SQL Server Agent Service statusThe SQL Server Agent Service status matches the status specified. 222800SQL Server Reporting Service statusThe SQL Server Reporting Service status matches the status specified. 232900SQL Server Full Text Search Service statusThe SQL Server Full Text Search Service status matches the status specified. 243000SQL Server Analysis Service statusThe SQL Server Analysis Service status matches the status specified. 253100SQL Server Integration Service statusThe SQL Server Integration Service status matches the status specified. 263300SQL Server Browser Service statusThe SQL Server Browser Service status matches the status specified. 273400SQL Server VSS Writer Service statusThe SQL Server VSS Writer status matches the status specified. 283501Deadlock trace flag disabledThe monitored SQL Server’s trace flag cannot be enabled. 293600Monitoring stopped (host machine credentials)SQL Monitor cannot contact the host machine because authentication failed. 303700Monitoring stopped (SQL Server credentials)SQL Monitor cannot contact the SQL Server instance because authentication failed. 313800Monitoring error (host machine data collection)SQL Monitor cannot collect data from the host machine. 323900Monitoring error (SQL Server data collection)SQL Monitor cannot collect data from the SQL Server instance. 334000Custom metricThe custom metric value has passed an alert threshold. 344100Custom metric collection errorSQL Monitor cannot collect custom metric data from the target object. Basically, alert.Alert_Type is just a big reference table containing information about the 34 different alert types supported by SQL Monitor (note that the largest id is 41, not 34 – some alert types have been retired since SQL Monitor was first developed). The Name and Description columns are self evident, and I’m going to skip over the Event and Monitoring columns as they’re not very interesting. The AlertId column is the primary key, and is referenced by AlertId in the alert.Alert table. As such, we can rewrite our earlier query to join these two tables, in order to provide a more readable view of the alerts: SELECT TOP 100 AlertId, Name, TargetObject, [Read], SubType FROM alert.Alert a JOIN alert.Alert_Type at ON a.AlertType = at.AlertType ORDER BY AlertId DESC; AlertIdNameTargetObjectReadSubType 165550Monitoring error (SQL Server data collection)7:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,9:SqlServer,1,4:Name,s0:,00 265549Monitoring error (host machine data collection)7:Cluster,1,4:Name,s29:srp-mr03.testnet.red-gate.com,7:Machine,1,4:Name,s0:,00 365548Integrity check overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 465547Log backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 565546Backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s15:FavouriteThings,00 665545Integrity check overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 765544Log backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 865543Backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,00 965542Integrity check overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 1065541Backup overdue7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s4:msdb,00 Okay, the next column to discuss in the alert.Alert table is TargetObject. Oh boy, this one’s a bit tricky! The TargetObject of an alert is a serialized string representation of the position in the monitored object hierarchy of the object to which the alert pertains. The serialization format is somewhat convenient for parsing in the C# source code of SQL Monitor, and has some helpful characteristics, but it’s probably very awkward to manipulate in T-SQL. I could document the serialization format here, but it would be very dry reading, so perhaps it’s best to consider an example from the table above. Have a look at the alert with an AlertID of 65543. It’s a Backup overdue alert for the SqlMonitorData database running on the default instance of granger, my laptop. Each different alert type is associated with a specific type of monitored object in the object hierarchy (I described the hierarchy in my previous post). The Backup overdue alert is associated with databases, whose position in the object hierarchy is root → Cluster → SqlServer → Database. The TargetObject value identifies the target object by specifying the key properties at each level in the hierarchy, thus: Cluster: Name = "granger" SqlServer: Name = "" (an empty string, denoting the default instance) Database: Name = "SqlMonitorData" Well, look at the actual TargetObject value for this alert: "7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s14:SqlMonitorData,". It is indeed composed of three parts, one for each level in the hierarchy: Cluster: "7:Cluster,1,4:Name,s7:granger," SqlServer: "9:SqlServer,1,4:Name,s0:," Database: "8:Database,1,4:Name,s14:SqlMonitorData," Each part is handled in exactly the same way, so let’s concentrate on the first part, "7:Cluster,1,4:Name,s7:granger,". It comprises the following: "7:Cluster," – This identifies the level in the hierarchy. "1," – This indicates how many different key properties there are to uniquely identify a cluster (we saw in my last post that each cluster is identified by a single property, its Name). "4:Name,s14:SqlMonitorData," – This represents the Name property, and its corresponding value, SqlMonitorData. It’s split up like this: "4:Name," – Indicates the name of the key property. "s" – Indicates the type of the key property, in this case, it’s a string. "14:SqlMonitorData," – Indicates the value of the property. At this point, you might be wondering about the format of some of these strings. Why is the string "Cluster" stored as "7:Cluster,"? Well an encoding scheme is used, which consists of the following: "7" – This is the length of the string "Cluster" ":" – This is a delimiter between the length of the string and the actual string’s contents. "Cluster" – This is the string itself. 7 characters. "," – This is a final terminating character that indicates the end of the encoded string. You can see that "4:Name,", "8:Database," and "14:SqlMonitorData," also conform to the same encoding scheme. In the example above, the "s" character is used to indicate that the value of the Name property is a string. If you explore the TargetObject property of alerts in your own SQL Monitor data repository, you might find other characters used for other non-string key property values. The different value types you might possibly encounter are as follows: "I" – Denotes a bigint value. For example, "I65432,". "g" – Denotes a GUID value. For example, "g32116732-63ae-4ab5-bd34-7dfdfb084c18,". "d" – Denotes a datetime value. For example, "d634815384796832438,". The value is stored as a bigint, rather than a native SQL datetime value. I’ll describe how datetime values are handled in the SQL Monitor data repostory in a future post. I suggest you have a look at the alerts in your own SQL Monitor data repository for further examples, so you can see how the TargetObject values are composed for each of the different types of alert. Let me give one further example, though, that represents a Custom metric alert, as this will help in describing the final column of interest in the alert.Alert table, SubType. Let me show you the alert I’m interested in: SELECT AlertId, a.AlertType, Name, TargetObject, [Read], SubType FROM alert.Alert a JOIN alert.Alert_Type at ON a.AlertType = at.AlertType WHERE AlertId = 65769; AlertIdAlertTypeNameTargetObjectReadSubType 16576940Custom metric7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s6:master,12:CustomMetric,1,8:MetricId,I2,02 An AlertType value of 40 corresponds to the Custom metric alert type. The Name taken from the alert.Alert_Type table is simply Custom metric, but this doesn’t tell us anything about the specific custom metric that this alert pertains to. That’s where the SubType value comes in. For custom metric alerts, this provides us with the Id of the specific custom alert definition that can be found in the settings.CustomAlertDefinitions table. I don’t really want to delve into custom alert definitions yet (maybe in a later post), but an extra join in the previous query shows us that this alert pertains to the CPU pressure (avg runnable task count) custom metric alert. SELECT AlertId, a.AlertType, at.Name, cad.Name AS CustomAlertName, TargetObject, [Read], SubType FROM alert.Alert a JOIN alert.Alert_Type at ON a.AlertType = at.AlertType JOIN settings.CustomAlertDefinitions cad ON a.SubType = cad.Id WHERE AlertId = 65769; AlertIdAlertTypeNameCustomAlertNameTargetObjectReadSubType 16576940Custom metricCPU pressure (avg runnable task count)7:Cluster,1,4:Name,s7:granger,9:SqlServer,1,4:Name,s0:,8:Database,1,4:Name,s6:master,12:CustomMetric,1,8:MetricId,I2,02 The TargetObject value in this case breaks down like this: "7:Cluster,1,4:Name,s7:granger," – Cluster named "granger". "9:SqlServer,1,4:Name,s0:," – SqlServer named "" (the default instance). "8:Database,1,4:Name,s6:master," – Database named "master". "12:CustomMetric,1,8:MetricId,I2," – Custom metric with an Id of 2. Note that the hierarchy for a custom metric is slightly different compared to the earlier Backup overdue alert. It’s root → Cluster → SqlServer → Database → CustomMetric. Also notice that, unlike Cluster, SqlServer and Database, the key property for CustomMetric is called MetricId (not Name), and the value is a bigint (not a string). Finally, delving into the custom metric tables is beyond the scope of this post, but for the sake of avoiding any future confusion, I’d like to point out that whilst the SubType references a custom alert definition, the MetricID value embedded in the TargetObject value references a custom metric definition. Although in this case both the custom metric definition and custom alert definition share the same Id value of 2, this is not generally the case. Okay, that’s enough for now, not least because as I’m typing this, it’s almost 2am, I have to go to work tomorrow, and my alarm is set for 6am – eek! In my next post, I’ll either cover the remaining three tables in the alert schema, or I’ll delve into the way SQL Monitor stores its monitoring data, as I’d originally planned to cover in this post.

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Silverlight Tree View with Multiple Levels

- by psheriff

There are many examples of the Silverlight Tree View that you will find on the web, however, most of them only show you how to go to two levels. What if you have more than two levels? This is where understanding exactly how the Hierarchical Data Templates works is vital. In this blog post, I am going to break down how these templates work so you can really understand what is going on underneath the hood. To start, let’s look at the typical two-level Silverlight Tree View that has been hard coded with the values shown below: <sdk:TreeView> <sdk:TreeViewItem Header="Managers"> <TextBlock Text="Michael" /> <TextBlock Text="Paul" /> </sdk:TreeViewItem> <sdk:TreeViewItem Header="Supervisors"> <TextBlock Text="John" /> <TextBlock Text="Tim" /> <TextBlock Text="David" /> </sdk:TreeViewItem></sdk:TreeView> Figure 1 shows you how this tree view looks when you run the Silverlight application. Figure 1: A hard-coded, two level Tree View. Next, let’s create three classes to mimic the hard-coded Tree View shown above. First, you need an Employee class and an EmployeeType class. The Employee class simply has one property called Name. The constructor is created to accept a “name” argument that you can use to set the Name property when you create an Employee object. public class Employee{ public Employee(string name) { Name = name; } public string Name { get; set; }} Finally you create an EmployeeType class. This class has one property called EmpType and contains a generic List<> collection of Employee objects. The property that holds the collection is called Employees. public class EmployeeType{ public EmployeeType(string empType) { EmpType = empType; Employees = new List<Employee>(); } public string EmpType { get; set; } public List<Employee> Employees { get; set; }} Finally we have a collection class called EmployeeTypes created using the generic List<> class. It is in the constructor for this class where you will build the collection of EmployeeTypes and fill it with Employee objects: public class EmployeeTypes : List<EmployeeType>{ public EmployeeTypes() { EmployeeType type; type = new EmployeeType("Manager"); type.Employees.Add(new Employee("Michael")); type.Employees.Add(new Employee("Paul")); this.Add(type); type = new EmployeeType("Project Managers"); type.Employees.Add(new Employee("Tim")); type.Employees.Add(new Employee("John")); type.Employees.Add(new Employee("David")); this.Add(type); }} You now have a data hierarchy in memory (Figure 2) which is what the Tree View control expects to receive as its data source. Figure 2: A hierachial data structure of Employee Types containing a collection of Employee objects. To connect up this hierarchy of data to your Tree View you create an instance of the EmployeeTypes class in XAML as shown in line 13 of Figure 3. The key assigned to this object is “empTypes”. This key is used as the source of data to the entire Tree View by setting the ItemsSource property as shown in Figure 3, Callout #1. Figure 3: You need to start from the bottom up when laying out your templates for a Tree View. The ItemsSource property of the Tree View control is used as the data source in the Hierarchical Data Template with the key of employeeTypeTemplate. In this case there is only one Hierarchical Data Template, so any data you wish to display within that template comes from the collection of Employee Types. The TextBlock control in line 20 uses the EmpType property of the EmployeeType class. You specify the name of the Hierarchical Data Template to use in the ItemTemplate property of the Tree View (Callout #2). For the second (and last) level of the Tree View control you use a normal <DataTemplate> with the name of employeeTemplate (line 14). The Hierarchical Data Template in lines 17-21 sets its ItemTemplate property to the key name of employeeTemplate (Line 19 connects to Line 14). The source of the data for the <DataTemplate> needs to be a property of the EmployeeTypes collection used in the Hierarchical Data Template. In this case that is the Employees property. In the Employees property there is a “Name” property of the Employee class that is used to display the employee name in the second level of the Tree View (Line 15). What is important here is that your lowest level in your Tree View is expressed in a <DataTemplate> and should be listed first in your Resources section. The next level up in your Tree View should be a <HierarchicalDataTemplate> which has its ItemTemplate property set to the key name of the <DataTemplate> and the ItemsSource property set to the data you wish to display in the <DataTemplate>. The Tree View control should have its ItemsSource property set to the data you wish to display in the <HierarchicalDataTemplate> and its ItemTemplate property set to the key name of the <HierarchicalDataTemplate> object. It is in this way that you get the Tree View to display all levels of your hierarchical data structure. Three Levels in a Tree View Now let’s expand upon this concept and use three levels in our Tree View (Figure 4). This Tree View shows that you now have EmployeeTypes at the top of the tree, followed by a small set of employees that themselves manage employees. This means that the EmployeeType class has a collection of Employee objects. Each Employee class has a collection of Employee objects as well. Figure 4: When using 3 levels in your TreeView you will have 2 Hierarchical Data Templates and 1 Data Template. The EmployeeType class has not changed at all from our previous example. However, the Employee class now has one additional property as shown below: public class Employee{ public Employee(string name) { Name = name; ManagedEmployees = new List<Employee>(); } public string Name { get; set; } public List<Employee> ManagedEmployees { get; set; }} The next thing that changes in our code is the EmployeeTypes class. The constructor now needs additional code to create a list of managed employees. Below is the new code. public class EmployeeTypes : List<EmployeeType>{ public EmployeeTypes() { EmployeeType type; Employee emp; Employee managed; type = new EmployeeType("Manager"); emp = new Employee("Michael"); managed = new Employee("John"); emp.ManagedEmployees.Add(managed); managed = new Employee("Tim"); emp.ManagedEmployees.Add(managed); type.Employees.Add(emp); emp = new Employee("Paul"); managed = new Employee("Michael"); emp.ManagedEmployees.Add(managed); managed = new Employee("Sara"); emp.ManagedEmployees.Add(managed); type.Employees.Add(emp); this.Add(type); type = new EmployeeType("Project Managers"); type.Employees.Add(new Employee("Tim")); type.Employees.Add(new Employee("John")); type.Employees.Add(new Employee("David")); this.Add(type); }} Now that you have all of the data built in your classes, you are now ready to hook up this three-level structure to your Tree View. Figure 5 shows the complete XAML needed to hook up your three-level Tree View. You can see in the XAML that there are now two Hierarchical Data Templates and one Data Template. Again you list the Data Template first since that is the lowest level in your Tree View. The next Hierarchical Data Template listed is the next level up from the lowest level, and finally you have a Hierarchical Data Template for the first level in your tree. You need to work your way from the bottom up when creating your Tree View hierarchy. XAML is processed from the top down, so if you attempt to reference a XAML key name that is below where you are referencing it from, you will get a runtime error. Figure 5: For three levels in a Tree View you will need two Hierarchical Data Templates and one Data Template. Each Hierarchical Data Template uses the previous template as its ItemTemplate. The ItemsSource of each Hierarchical Data Template is used to feed the data to the previous template. This is probably the most confusing part about working with the Tree View control. You are expecting the content of the current Hierarchical Data Template to use the properties set in the ItemsSource property of that template. But you need to look to the template lower down in the XAML to see the source of the data as shown in Figure 6. Figure 6: The properties you use within the Content of a template come from the ItemsSource of the next template in the resources section. Summary Understanding how to put together your hierarchy in a Tree View is simple once you understand that you need to work from the bottom up. Start with the bottom node in your Tree View and determine what that will look like and where the data will come from. You then build the next Hierarchical Data Template to feed the data to the previous template you created. You keep doing this for each level in your Tree View until you get to the last level. The data for that last Hierarchical Data Template comes from the ItemsSource in the Tree View itself. NOTE: You can download the sample code for this article by visiting my website at http://www.pdsa.com/downloads. Select “Tips & Tricks”, then select “Silverlight TreeView with Multiple Levels” from the drop down list.

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Internet Explorer and Cookie Domains

- by Rick Strahl

I've been bitten by some nasty issues today in regards to using a domain cookie as part of my FormsAuthentication operations. In the app I'm currently working on we need to have single sign-on that spans multiple sub-domains (www.domain.com, store.domain.com, mail.domain.com etc.). That's what a domain cookie is meant for - when you set the cookie with a Domain value of the base domain the cookie stays valid for all sub-domains. I've been testing the app for quite a while and everything is working great. Finally I get around to checking the app with Internet Explorer and I start discovering some problems - specifically on my local machine using localhost. It appears that Internet Explorer (all versions) doesn't allow you to specify a domain of localhost, a local IP address or machine name. When you do, Internet Explorer simply ignores the cookie. In my last post I talked about some generic code I created to basically parse out the base domain from the current URL so a domain cookie would automatically used using this code:private void IssueAuthTicket(UserState userState, bool rememberMe) { FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1, userState.UserId, DateTime.Now, DateTime.Now.AddDays(10), rememberMe, userState.ToString()); string ticketString = FormsAuthentication.Encrypt(ticket); HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, ticketString); cookie.HttpOnly = true; if (rememberMe) cookie.Expires = DateTime.Now.AddDays(10); var domain = Request.Url.GetBaseDomain(); if (domain != Request.Url.DnsSafeHost) cookie.Domain = domain; HttpContext.Response.Cookies.Add(cookie); } This code works fine on all browsers but Internet Explorer both locally and on full domains. And it also works fine for Internet Explorer with actual 'real' domains. However, this code fails silently for IE when the domain is localhost or any other local address. In that case Internet Explorer simply refuses to accept the cookie and fails to log in. Argh! The end result is that the solution above trying to automatically parse the base domain won't work as local addresses end up failing. Configuration Setting Given this screwed up state of affairs, the best solution to handle this is a configuration setting. Forms Authentication actually has a domain key that can be set for FormsAuthentication so that's natural choice for the storing the domain name: <authentication mode="Forms"> <forms loginUrl="~/Account/Login" name="gnc" domain="mydomain.com" slidingExpiration="true" timeout="30" xdt:Transform="Replace"/> </authentication> Although I'm not actually letting FormsAuth set my cookie directly I can still access the domain name from the static FormsAuthentication.CookieDomain property, by changing the domain assignment code to:if (!string.IsNullOrEmpty(FormsAuthentication.CookieDomain)) cookie.Domain = FormsAuthentication.CookieDomain; The key is to only set the domain when actually running on a full authority, and leaving the domain key blank on the local machine to avoid the local address debacle. Note if you want to see this fail with IE, set the domain to domain="localhost" and watch in Fiddler what happens. Logging Out When specifying a domain key for a login it's also vitally important that that same domain key is used when logging out. Forms Authentication will do this automatically for you when the domain is set and you use FormsAuthentication.SignOut(). If you use an explicit Cookie to manage your logins or other persistant value, make sure that when you log out you also specify the domain. IOW, the expiring cookie you set for a 'logout' should match the same settings - name, path, domain - as the cookie you used to set the value.HttpCookie cookie = new HttpCookie("gne", ""); cookie.Expires = DateTime.Now.AddDays(-5); // make sure we use the same logic to release cookie var domain = Request.Url.GetBaseDomain(); if (domain != Request.Url.DnsSafeHost) cookie.Domain = domain; HttpContext.Response.Cookies.Add(cookie); I managed to get my code to do what I needed it to, but man I'm getting so sick and tired of fixing IE only bugs. I spent most of the day today fixing a number of small IE layout bugs along with this issue which took a bit of time to trace down.© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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C#/.NET Little Wonders: The Joy of Anonymous Types

- by James Michael Hare

Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. In the .NET 3 Framework, Microsoft introduced the concept of anonymous types, which provide a way to create a quick, compiler-generated types at the point of instantiation. These may seem trivial, but are very handy for concisely creating lightweight, strongly-typed objects containing only read-only properties that can be used within a given scope. Creating an Anonymous Type In short, an anonymous type is a reference type that derives directly from object and is defined by its set of properties base on their names, number, types, and order given at initialization. In addition to just holding these properties, it is also given appropriate overridden implementations for Equals() and GetHashCode() that take into account all of the properties to correctly perform property comparisons and hashing. Also overridden is an implementation of ToString() which makes it easy to display the contents of an anonymous type instance in a fairly concise manner. To construct an anonymous type instance, you use basically the same initialization syntax as with a regular type. So, for example, if we wanted to create an anonymous type to represent a particular point, we could do this: 1: var point = new { X = 13, Y = 7 }; Note the similarity between anonymous type initialization and regular initialization. The main difference is that the compiler generates the type name and the properties (as readonly) based on the names and order provided, and inferring their types from the expressions they are assigned to. It is key to remember that all of those factors (number, names, types, order of properties) determine the anonymous type. This is important, because while these two instances share the same anonymous type: 1: // same names, types, and order 2: var point1 = new { X = 13, Y = 7 }; 3: var point2 = new { X = 5, Y = 0 }; These similar ones do not: 1: var point3 = new { Y = 3, X = 5 }; // different order 2: var point4 = new { X = 3, Y = 5.0 }; // different type for Y 3: var point5 = new {MyX = 3, MyY = 5 }; // different names 4: var point6 = new { X = 1, Y = 2, Z = 3 }; // different count Limitations on Property Initialization Expressions The expression for a property in an anonymous type initialization cannot be null (though it can evaluate to null) or an anonymous function. For example, the following are illegal: 1: // Null can't be used directly. Null reference of what type? 2: var cantUseNull = new { Value = null }; 3: 4: // Anonymous methods cannot be used. 5: var cantUseAnonymousFxn = new { Value = () => Console.WriteLine(“Can’t.”) }; Note that the restriction on null is just that you can’t use it directly as the expression, because otherwise how would it be able to determine the type? You can, however, use it indirectly assigning a null expression such as a typed variable with the value null, or by casting null to a specific type: 1: string str = null; 2: var fineIndirectly = new { Value = str }; 3: var fineCast = new { Value = (string)null }; All of the examples above name the properties explicitly, but you can also implicitly name properties if they are being set from a property, field, or variable. In these cases, when a field, property, or variable is used alone, and you don’t specify a property name assigned to it, the new property will have the same name. For example: 1: int variable = 42; 2: 3: // creates two properties named varriable and Now 4: var implicitProperties = new { variable, DateTime.Now }; Is the same type as: 1: var explicitProperties = new { variable = variable, Now = DateTime.Now }; But this only works if you are using an existing field, variable, or property directly as the expression. If you use a more complex expression then the name cannot be inferred: 1: // can't infer the name variable from variable * 2, must name explicitly 2: var wontWork = new { variable * 2, DateTime.Now }; In the example above, since we typed variable * 2, it is no longer just a variable and thus we would have to assign the property a name explicitly. ToString() on Anonymous Types One of the more trivial overrides that an anonymous type provides you is a ToString() method that prints the value of the anonymous type instance in much the same format as it was initialized (except actual values instead of expressions as appropriate of course). For example, if you had: 1: var point = new { X = 13, Y = 42 }; And then print it out: 1: Console.WriteLine(point.ToString()); You will get: 1: { X = 13, Y = 42 } While this isn’t necessarily the most stunning feature of anonymous types, it can be handy for debugging or logging values in a fairly easy to read format. Comparing Anonymous Type Instances Because anonymous types automatically create appropriate overrides of Equals() and GetHashCode() based on the underlying properties, we can reliably compare two instances or get hash codes. For example, if we had the following 3 points: 1: var point1 = new { X = 1, Y = 2 }; 2: var point2 = new { X = 1, Y = 2 }; 3: var point3 = new { Y = 2, X = 1 }; If we compare point1 and point2 we’ll see that Equals() returns true because they overridden version of Equals() sees that the types are the same (same number, names, types, and order of properties) and that the values are the same. In addition, because all equal objects should have the same hash code, we’ll see that the hash codes evaluate to the same as well: 1: // true, same type, same values 2: Console.WriteLine(point1.Equals(point2)); 3: 4: // true, equal anonymous type instances always have same hash code 5: Console.WriteLine(point1.GetHashCode() == point2.GetHashCode()); However, if we compare point2 and point3 we get false. Even though the names, types, and values of the properties are the same, the order is not, thus they are two different types and cannot be compared (and thus return false). And, since they are not equal objects (even though they have the same value) there is a good chance their hash codes are different as well (though not guaranteed): 1: // false, different types 2: Console.WriteLine(point2.Equals(point3)); 3: 4: // quite possibly false (was false on my machine) 5: Console.WriteLine(point2.GetHashCode() == point3.GetHashCode()); Using Anonymous Types Now that we’ve created instances of anonymous types, let’s actually use them. The property names (whether implicit or explicit) are used to access the individual properties of the anonymous type. The main thing, once again, to keep in mind is that the properties are readonly, so you cannot assign the properties a new value (note: this does not mean that instances referred to by a property are immutable – for more information check out C#/.NET Fundamentals: Returning Data Immutably in a Mutable World). Thus, if we have the following anonymous type instance: 1: var point = new { X = 13, Y = 42 }; We can get the properties as you’d expect: 1: Console.WriteLine(“The point is: ({0},{1})”, point.X, point.Y); But we cannot alter the property values: 1: // compiler error, properties are readonly 2: point.X = 99; Further, since the anonymous type name is only known by the compiler, there is no easy way to pass anonymous type instances outside of a given scope. The only real choices are to pass them as object or dynamic. But really that is not the intention of using anonymous types. If you find yourself needing to pass an anonymous type outside of a given scope, you should really consider making a POCO (Plain Old CLR Type – i.e. a class that contains just properties to hold data with little/no business logic) instead. Given that, why use them at all? Couldn’t you always just create a POCO to represent every anonymous type you needed? Sure you could, but then you might litter your solution with many small POCO classes that have very localized uses. It turns out this is the key to when to use anonymous types to your advantage: when you just need a lightweight type in a local context to store intermediate results, consider an anonymous type – but when that result is more long-lived and used outside of the current scope, consider a POCO instead. So what do we mean by intermediate results in a local context? Well, a classic example would be filtering down results from a LINQ expression. For example, let’s say we had a List<Transaction>, where Transaction is defined something like: 1: public class Transaction 2: { 3: public string UserId { get; set; } 4: public DateTime At { get; set; } 5: public decimal Amount { get; set; } 6: // … 7: } And let’s say we had this data in our List<Transaction>: 1: var transactions = new List<Transaction> 2: { 3: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = 2200.00m }, 4: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = -1100.00m }, 5: new Transaction { UserId = "Jim", At = DateTime.Now.AddDays(-1), Amount = 900.00m }, 6: new Transaction { UserId = "John", At = DateTime.Now.AddDays(-2), Amount = 300.00m }, 7: new Transaction { UserId = "John", At = DateTime.Now, Amount = -10.00m }, 8: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = 200.00m }, 9: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = -50.00m }, 10: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = -100.00m }, 11: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = 300.00m }, 12: }; So let’s say we wanted to get the transactions for each day for each user. That is, for each day we’d want to see the transactions each user performed. We could do this very simply with a nice LINQ expression, without the need of creating any POCOs: 1: // group the transactions based on an anonymous type with properties UserId and Date: 2: byUserAndDay = transactions 3: .GroupBy(tx => new { tx.UserId, tx.At.Date }) 4: .OrderBy(grp => grp.Key.Date) 5: .ThenBy(grp => grp.Key.UserId); Now, those of you who have attempted to use custom classes as a grouping type before (such as GroupBy(), Distinct(), etc.) may have discovered the hard way that LINQ gets a lot of its speed by utilizing not on Equals(), but also GetHashCode() on the type you are grouping by. Thus, when you use custom types for these purposes, you generally end up having to write custom Equals() and GetHashCode() implementations or you won’t get the results you were expecting (the default implementations of Equals() and GetHashCode() are reference equality and reference identity based respectively). As we said before, it turns out that anonymous types already do these critical overrides for you. This makes them even more convenient to use! Instead of creating a small POCO to handle this grouping, and then having to implement a custom Equals() and GetHashCode() every time, we can just take advantage of the fact that anonymous types automatically override these methods with appropriate implementations that take into account the values of all of the properties. Now, we can look at our results: 1: foreach (var group in byUserAndDay) 2: { 3: // the group’s Key is an instance of our anonymous type 4: Console.WriteLine("{0} on {1:MM/dd/yyyy} did:", group.Key.UserId, group.Key.Date); 5: 6: // each grouping contains a sequence of the items. 7: foreach (var tx in group) 8: { 9: Console.WriteLine("\t{0}", tx.Amount); 10: } 11: } And see: 1: Jaime on 06/18/2012 did: 2: -100.00 3: 300.00 4: 5: John on 06/19/2012 did: 6: 300.00 7: 8: Jim on 06/20/2012 did: 9: 900.00 10: 11: Jane on 06/21/2012 did: 12: 200.00 13: -50.00 14: 15: Jim on 06/21/2012 did: 16: 2200.00 17: -1100.00 18: 19: John on 06/21/2012 did: 20: -10.00 Again, sure we could have just built a POCO to do this, given it an appropriate Equals() and GetHashCode() method, but that would have bloated our code with so many extra lines and been more difficult to maintain if the properties change. Summary Anonymous types are one of those Little Wonders of the .NET language that are perfect at exactly that time when you need a temporary type to hold a set of properties together for an intermediate result. While they are not very useful beyond the scope in which they are defined, they are excellent in LINQ expressions as a way to create and us intermediary values for further expressions and analysis. Anonymous types are defined by the compiler based on the number, type, names, and order of properties created, and they automatically implement appropriate Equals() and GetHashCode() overrides (as well as ToString()) which makes them ideal for LINQ expressions where you need to create a set of properties to group, evaluate, etc. Technorati Tags: C#,CSharp,.NET,Little Wonders,Anonymous Types,LINQ

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- by Chris Lambrou

- by psheriff

- by Rick Strahl

- by James Michael Hare

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