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  • Configuring Application/User Settings in WPF the easy way.

    - by mbcrump
    In this tutorial, we are going to configure the application/user settings in a WPF application the easy way. Most example that I’ve seen on the net involve the ConfigurationManager class and involve creating your own XML file from scratch. I am going to show you a easier way to do it. (in my humble opinion) First, the definitions: User Setting – is designed to be something specific to the user. For example, one user may have a requirement to see certain stocks, news articles or local weather. This can be set at run-time. Application Setting – is designed to store information such as a database connection string. These settings are read-only at run-time. 1) Lets create a new WPF Project and play with a few settings. Once you are inside VS, then paste the following code snippet inside the <Grid> tags. <Grid> <TextBox Height="23" HorizontalAlignment="Left" Margin="12,11,0,0" Name="textBox1" VerticalAlignment="Top" Width="285" Grid.ColumnSpan="2" /> <Button Content="Set Title" Name="button2" Click="button2_Click" Margin="108,40,96,114" /> <TextBlock Height="23" Name="textBlock1" Text="TextBlock" VerticalAlignment="Bottom" Width="377" /> </Grid> Basically, its just a Textbox, Button and TextBlock. The main Window should look like the following:   2) Now we are going to setup our Configuration Settings. Look in the Solution Explorer and double click on the Settings.settings file. Make sure that your settings file looks just like mine included below:   What just happened was the designer created an XML file and created the Settings.Designer.cs file which looks like this: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace WPFExam.Properties { [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()] [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "10.0.0.0")] internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase { private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings()))); public static Settings Default { get { return defaultInstance; } } [global::System.Configuration.UserScopedSettingAttribute()] [global::System.Diagnostics.DebuggerNonUserCodeAttribute()] [global::System.Configuration.DefaultSettingValueAttribute("ApplicationName")] public string ApplicationName { get { return ((string)(this["ApplicationName"])); } set { this["ApplicationName"] = value; } } [global::System.Configuration.ApplicationScopedSettingAttribute()] [global::System.Diagnostics.DebuggerNonUserCodeAttribute()] [global::System.Configuration.DefaultSettingValueAttribute("SQL_SRV342")] public string DatabaseServerName { get { return ((string)(this["DatabaseServerName"])); } } } } The XML File is named app.config and looks like this: <?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" > <section name="WPFExam.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" /> </sectionGroup> <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" > <section name="WPFExam.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /> </sectionGroup> </configSections> <userSettings> <WPFExam.Properties.Settings> <setting name="ApplicationName" serializeAs="String"> <value>ApplicationName</value> </setting> </WPFExam.Properties.Settings> </userSettings> <applicationSettings> <WPFExam.Properties.Settings> <setting name="DatabaseServerName" serializeAs="String"> <value>SQL_SRV342</value> </setting> </WPFExam.Properties.Settings> </applicationSettings> </configuration> 3) The only left now is the code behind the button. Double click the button and replace the MainWindow() method with the following code snippet. public MainWindow() { InitializeComponent(); this.Title = Properties.Settings.Default.ApplicationName; textBox1.Text = Properties.Settings.Default.ApplicationName; textBlock1.Text = Properties.Settings.Default.DatabaseServerName; } private void button2_Click(object sender, RoutedEventArgs e) { Properties.Settings.Default.ApplicationName = textBox1.Text.ToString(); Properties.Settings.Default.Save(); } Run the application and type something in the textbox and hit the Set Title button. Now, restart the application and you should see the text that you entered earlier.   If you look at the button2 click event, you will see that it was actually 2 lines of codes to save to the configuration file. I hope this helps, for more information consult MSDN.

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  • Problem with linq-to-xml

    - by phenevo
    I want by linq save my xml in csv and I have o problem. This bracket are here beacuse without it this code is not displaying (why ? ) bracket results bracket <Countries country="Albania"><Regions region="Centralna Albania"><Provinces province="Durres i okolice"><Cities city="Durres" cityCode="2B66E0ACFAEF78734E3AF1194BFA6F8DEC4C5760"><IndividualFlagsWithForObjects Status="1" /><IndividualFlagsWithForObjects Status="0" /><IndividualFlagsWithForObjects magazyn="2" /></Cities></Provinces></Regions></Countries><Countries .... XDocument loaded = XDocument.Load(@"c:\citiesxml.xml"); // create a writer and open the file TextWriter tw = new StreamWriter("c:\\XmltoCSV.txt"); // Query the data and write out a subset of contacts var contacts = (from c in loaded.Descendants("Countries") select new { Country = (string)c.Element("Country"), Region = (string)c.Element("region"), Province= (string)c.Element("province"), City = (string)c.Element("city"), Hotel = (string)c.Element("hotel") }).ToList(); Problem is that loaded.Descendants("Countries") gives me 45 countries but all fields are null.

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  • How to optimize erasing from multimap

    - by Dominating
    I have two multimaps defined so multimap phoneNums; and multimap numPhones; they are some kind of phone registry - phoneNums contains Key name, and second argument phonenumber, numPhones contain Key phonenumber and second is name. I want to optimize erase from both of them when i want to delete string Key form phoneNums, which is also second element in numPhones. When i enter data it is entered in both multimaps so they are actually the same but with swapped first and second when i put it on tests it says that erasing is too slow - N*N and must be only N cin>>stringToErase; phoneNums.erase(stringToErase); multimap<string, string>::iterator it; multimap<string, string>::iterator tmpr; for(it = numPhones.begin(); it != numPhones.end();it++) { if(it->second == tringToErase) { tmpr = it; numPhones.erase(it,tmpr); } }

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  • Ignore errors when scanning for files in C:\

    - by Shane
    I am trying to search the C:\ drive for all files with a certain extension. I am using the following code which is working fine, however when it encounters an error the whole process stops rather than continuing with the scan. (running in backgroundworker, hence the invoke) Private Sub ScanFiles(ByVal rootFolder As String, ByVal fileExtension As String) 'Determine if the current folder contains any sub folders Dim subFolders() As String = System.IO.Directory.GetDirectories(rootFolder) For Each subFolder As String In subFolders ScanFiles(subFolder, fileExtension) Next For Each file As String In System.IO.Directory.GetFiles(rootFolder, fileExtension) lb.BeginInvoke(New AddValue(AddressOf AddItems), file) Next End Sub How can I make this code continue once an error is encountered? Thanks for your help.

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  • C#: Put member variables into a list.

    - by David
    Hi all Assuming I have a method which accepts an IList or similar thing as a parameter: public void JiggleMyList(IList<string> list)... Is there an easy way that I can pass in string members of a list of objects? I mean, if for example, I have a list of Person objects which expose a string property called FullName, is there a quick way to stuff the FullNames of all the Person objects into the method parameter, or do I have to create a new List and iterate through the Person objects: List<string> fullNames = new List<string>; foreach (Person person in people) { fullNames.Add(person.FullName); } JiggleMyList(fullNames); I come across this all the time, and it would be nice if there was a shortcut. Many thanks David

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  • ERRNO: 2 Division by zero error

    - by chupinette
    I am getting this error : ERRNO: 2 TEXT: Division by zero I have the following function in my class Customer public static function GetQuotationDetails($string) { $sql = 'SELECT I.name, I.discounted_price, I.other_name FROM item I WHERE ( I.name LIKE CONCAT( '%', :string, '%' )) AND T.item_name=:string'; $parameters = array(':string' => $string); DB::GetAll($sql,$parameters); } Then, $this->results = Customer::GetQuotationDetails('grinder'); and i echo the results by echo $obj_quotations->results; Can anyone help me?

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  • Storing member function pointers of derived classes in map

    - by Kiran Mohan
    Hello, I am trying to implement a factory for two classes Circle, Square both of which inherits from Shape. class Shape { public: virtual static Shape * getInstance() = 0; }; class Circle : public Shape { public: static const std::string type; Shape * getInstance() { return new Circle; } }; const std::string Circle::type = "Circle"; class Square : public Shape { public: static const std::string type; Shape * getInstance() { return new Square; } }; const std::string Square::type = "Square"; I want to now create a map with key as shape type (string) and value as a function pointer to getInstance() of the corresponding derived class. Is it possible? Thanks, Kiran

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  • How to: WCF XML-RPC client?

    - by mr.b
    I have built my own little custom XML-RPC server, and since I'd like to keep things simple, on both server and client side, what I would like to accomplish is to create a simplest possible client (in C# preferably) using WCF. Let's say that Contract for service exposed via XML-RPC is as follows: [ServiceContract] public interface IContract { [OperationContract(Action="Ping")] string Ping(); // server returns back string "Pong" [OperationContract(Action="Echo")] string Echo(string message); // server echoes back whatever message is } So, there are two example methods, one without any arguments, and another with simple string argument, both returning strings (just for sake of example). Service is exposed via http. Aaand, what's next? :) P.S. I have tried googling around for samples and similar, but all that I could come up with are some blog-related samples that use existing (and very big/numerous) classes, which implement appropriate IContract (or IBlogger) interfaces, so that most of what I am interested is hidden below several layers of abstraction...

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  • STL map inside map C++

    - by Prasanth Madhavan
    In c++ STL map, i have a definition like map<string, map<int, string> >; and i iterate it using the following code. for( map<string, map<int, string> >::iterator ii=info.begin(); ii!=info.end(); ++ii){ for(map<int, string>::iterator j=ii->second.begin(); j!=ii->second.end();++j){ cout << (*ii).first << " : " << (*j).first << " : "<< (*j).second << endl; } } My doubt is is this the correct way to iterate or is there a better way to do so? The above code works for me. But m looking for a more elegant solution.

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  • Convert a generic list to an array

    - by Freewind
    I have searched for this, but unfortunately, I don't get the correct answer. class Helper { public static <T> T[] toArray(List<T> list) { T[] array = (T[]) new Object[list.size()]; for (int i = 0; i < list.size(); i++) { array[i] = list.get(i); } return array; } } Test it: public static void main(String[] args) { List<String> list = new ArrayList<String>(); list.add("abc"); String[] array = toArray(list); System.out.println(array); } But there is an error thrown: Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String; at test.Helper.main(Helper.java:30) How to solve this?

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  • Problem regarding listShuttle component in richFaces ?

    - by Hari
    I am a newbee for Richfaces components, When i am using the <rich:listShuttle> the Arraylist specified in the targetValue is now getting updated with the latest data? Kindly help MyJSF File <a4j:region> <rich:listShuttle sourceValue="#{bean.selectItems}" id="one" targetValue="#{bean.selectItemsone}" var="items" listsHeight="150" sourceListWidth="130" targetListWidth="130" sourceCaptionLabel="Intial Items" targetCaptionLabel="Selected Items" converter="Listconverter"> <rich:column> <h:outputText value="#{items.value}"></h:outputText> </rich:column> </rich:listShuttle> </a4j:region> <a4j:region> <a4j:commandButton value="Submit" action="#{bean.action}" /> </a4j:region> My Managed Bean enter code here private List<String> selectedData; private List<BeanItems> selectItems; private List<BeanItems> selectItemsone; public String action() { System.out.println(selectItems); System.out.println(selectItemsone); System.out.println("Select Item List"); Iterator<BeanItems> iterator = selectItems.iterator(); while (iterator.hasNext()) { BeanItems item = (BeanItems) iterator.next(); System.out.println(item.getValue()); } System.out.println("/nSelect Item one list "); Iterator<BeanItems> iterator2 = selectItemsone.iterator(); while (iterator2.hasNext()) { BeanItems item = (BeanItems) iterator2.next(); System.out.println(item.getValue()); } return ""; } public void setSelectedData(List<String> selectedData) { this.selectedData = selectedData; } public List<String> getSelectedData() { return selectedData; } /** * @return the selectItems */ public List<BeanItems> getSelectItems() { if (selectItems == null) { selectItems = new ArrayList<BeanItems>(); selectItems.add(new BeanItems("value4", "label4")); selectItems.add(new BeanItems("value5", "label5")); selectItems.add(new BeanItems("value6", "label6")); selectItems.add(new BeanItems("value7", "label7")); selectItems.add(new BeanItems("value8", "label8")); selectItems.add(new BeanItems("value9", "label9")); selectItems.add(new BeanItems("value10", "label10")); } return selectItems; } /** * @return the selectItemsone */ public List<BeanItems> getSelectItemsone() { if (selectItemsone == null) { selectItemsone = new ArrayList<BeanItems>(); selectItemsone.add(new BeanItems("value1", "label1")); selectItemsone.add(new BeanItems("value2", "label2")); selectItemsone.add(new BeanItems("value3", "label3")); } return selectItemsone; } My Converter Class enter code here public Object getAsObject(FacesContext context, UIComponent component,String value) { int index = value.indexOf(':'); return new BeanItems(value.substring(0, index), value.substring(index + 1)); } public String getAsString(FacesContext context, UIComponent component,Object value) { BeanItems beanItems = (BeanItems) value; return beanItems.getValue() + ":" + beanItems.getData(); } My BeanItems Class enter code here private String data; //Getter & setter private String value; //Getter & setter public BeanItems() { } public BeanItems(String value, String data) { this.value = value; this.data = data; } public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((data == null) ? 0 : data.hashCode()); result = prime * result + ((value == null) ? 0 : value.hashCode()); return result; } public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; final BeanItems other = (BeanItems) obj; if (data == null) { if (other.data != null) return false; } else if (!data.equals(other.data)) return false; if (value == null) { if (other.value != null) return false; } else if (!value.equals(other.value)) return false; return true; }

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  • How to Extract Properties for Refactoring

    - by Ngu Soon Hui
    I have this property public List<PointK> LineList {get;set;} Where PointK consists of the following structure: string Mark{get;set;} double X{get;set;} doible Y{get;set;} Now, I have the following code: private static Dictionary<string , double > GetY(List<PointK> points) { var invertedDictResult = new Dictionary<string, double>(); foreach (var point in points) { if (!invertedDictResult.ContainsKey(point.Mark)) { invertedDictResult.Add(point .Mark, Math.Round(point.Y, 4)); } } return invertedDictResult; } private static Dictionary<string , double > GetX(List<PointK> points) { var invertedDictResult = new Dictionary<string, double>(); foreach (var point in points) { if (!invertedDictResult.ContainsKey(point.Mark)) { invertedDictResult.Add(point .Mark, Math.Round(point.X, 4)); } } return invertedDictResult; } How to restructure the above code?

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  • SqlCommand asp.net C#

    - by emilios
    i you please help me out with my problem i am trying to create a function that output the data on a dropdownlist an setting my parameters my code goes as follow : public static List<string> GetTracks(out List<string> trackIds, string conferenceId) { var res = new List<string>(); trackIds = new List<string>(); var sqlCon = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString); SqlCommand cmd = new SqlCommand("select Track_name,Track_ID from TrackCommittee where Conference_id= @conferenceId", sqlCon); DataSet ds = new DataSet(); cmd.Connection.Open(); cmd.Parameters.Add(new SqlParameter("@conferenceId", conferenceId)); using (SqlDataReader sdr = cmd.ExecuteReader()) { while (sdr.Read()) { res.Add(sdr.GetString(sdr.GetOrdinal("Track_name"))); trackIds.Add(sdr.GetInt32(sdr.GetOrdinal("Track_ID")).ToString()); } } cmd.Connection.Close(); cmd.Dispose(); return res; } thanking you in advance

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  • SQL ADO.NET shortcut extensions (old school!)

    - by Jeff
    As much as I love me some ORM's (I've used LINQ to SQL quite a bit, and for the MSDN/TechNet Profile and Forums we're using NHibernate more and more), there are times when it's appropriate, and in some ways more simple, to just throw up so old school ADO.NET connections, commands, readers and such. It still feels like a pain though to new up all the stuff, make sure it's closed, blah blah blah. It's pretty much the least favorite task of writing data access code. To minimize the pain, I have a set of extension methods that I like to use that drastically reduce the code you have to write. Here they are... public static void Using(this SqlConnection connection, Action<SqlConnection> action) {     connection.Open();     action(connection);     connection.Close(); } public static SqlCommand Command(this SqlConnection connection, string sql){    var command = new SqlCommand(sql, connection);    return command;}public static SqlCommand AddParameter(this SqlCommand command, string parameterName, object value){    command.Parameters.AddWithValue(parameterName, value);    return command;}public static object ExecuteAndReturnIdentity(this SqlCommand command){    if (command.Connection == null)        throw new Exception("SqlCommand has no connection.");    command.ExecuteNonQuery();    command.Parameters.Clear();    command.CommandText = "SELECT @@IDENTITY";    var result = command.ExecuteScalar();    return result;}public static SqlDataReader ReadOne(this SqlDataReader reader, Action<SqlDataReader> action){    if (reader.Read())        action(reader);    reader.Close();    return reader;}public static SqlDataReader ReadAll(this SqlDataReader reader, Action<SqlDataReader> action){    while (reader.Read())        action(reader);    reader.Close();    return reader;} It has been awhile since I've really revisited these, so you will likely find opportunity for further optimization. The bottom line here is that you can chain together a bunch of these methods to make a much more concise database call, in terms of the code on your screen, anyway. Here are some examples: public Dictionary<string, string> Get(){    var dictionary = new Dictionary<string, string>();    _sqlHelper.GetConnection().Using(connection =>        connection.Command("SELECT Setting, [Value] FROM Settings")            .ExecuteReader()            .ReadAll(r => dictionary.Add(r.GetString(0), r.GetString(1))));    return dictionary;} or... public void ChangeName(User user, string newName){    _sqlHelper.GetConnection().Using(connection =>         connection.Command("UPDATE Users SET Name = @Name WHERE UserID = @UserID")            .AddParameter("@Name", newName)            .AddParameter("@UserID", user.UserID)            .ExecuteNonQuery());} The _sqlHelper.GetConnection() is just some other code that gets a connection object for you. You might have an even cleaner way to take that step out entirely. This looks more fluent, and the real magic sauce for me is the reader bits where you can put any kind of arbitrary method in there to iterate over the results.

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  • how to join a set of XElements to the values of a struct?

    - by jcollum
    Let's say I have a struct that contains local environments: public struct Environments { public const string Dev = "DEV"; public const string Qa1 = "SQA"; public const string Prod1 = "PROD"; public const string Prod2 = "PROD_SA"; public const string Uat = "UAT"; } And I'd like to pull a set of XElements out of an xml doc, but only those elements that have a key that matches a value in a struct. this.environments =(from e in settings.Element("Settings").Element("Environments") .Elements("Environment") .Where( x => x.HasAttribute("name") ) join f in [struct?] on e.Attribute("name") equals [struct value?]).ToDictionary(...) How would I go about doing this? Do I need reflection to get the values of the constants in the struct?

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  • Convert date time value to expected with SimpleDateFormat

    - by Khoi Nguyen
    I have an issue with converting a date time value to expected one with SimpleDateFormat (java), my expected format is MM/yyyy, and I want to convert 2 values to only 1 format MM-yyyy for example 05-2012 yyyy-MM for example 2012-05 ouput is 05/2012. I implemented something look like following String expiry = "2012-01"; try { result = convertDateFormat(expiry, "MM-yyyy", expectedFormat); } catch (ParseException e) { try { result = convertDateFormat(expiry, "yyyy-MM", expectedFormat); } catch (ParseException e1) { e1.printStackTrace(); } e.printStackTrace(); } private String convertDateFormat(String date, String oPattern, String ePattern) throws ParseException { SimpleDateFormat normalFormat = new SimpleDateFormat(oPattern); Date d = normalFormat.parse(date); SimpleDateFormat cardFormat = new SimpleDateFormat(ePattern); return cardFormat.format(d); } Now, the return value is 6808, I don't know why. Kindly anyone help me on this case.

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  • URL Encoding - Illegal Character Replacement

    - by ThePower
    Hi, I am doing some url redirections in a project that I am currently working on. I am new to web development and was wondering what the best practise was to remove any illegal path characters, such as ' ? etc. I'm hoping I don't have to resort to manually replacing each character with their encoded urls. I have tried UrlEncode and HTMLEncode, but UrlEncode doesn't cater for the ? and HTMLEncode doesn't cater for ' E.G. If I was to use the following: Dim name As String = "Dave's gone, why?" Dim url As String = String.Format("~/books/{0}/{1}/default.aspx", bookID, name) Response.Redirect(url) I've tried wrapping url like this: Dim encodedUrl As String = Server.UrlEncode(url) And Dim encodedUrl As String = Server.HTMLEncode(url) Thanks in advance. P.S. Happy Christmas

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  • what is means of this problem when sending email through web-application

    - by Richa Media and services
    i have this error when i sending email through our web application " Mailbox unavailable. The server response was: Requested action not taken: mailbox unavailable or not local" this is detail of error System.Net.Mail.SmtpFailedRecipientException was caught Message=Mailbox unavailable. The server response was: Requested action not taken: mailbox unavailable or not local Source=System FailedRecipient=<[email protected]> StackTrace: at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, SmtpFailedRecipientException& exception) at System.Net.Mail.SmtpClient.Send(MailMessage message) at email.Globals.SendMail(String EmailID, String subject, String message, String senderMail) in C:location InnerException:

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  • How to bind Dictionary with ComboBox and textbox?

    - by younevertell
    I have a Dictionary, where Person is a class, defined below String role; public class Person { public string firstname{ get; set; } public string lastname{ get; set; } public string city{ get; set; } } my question is how to bind the Dictionary key: String with a ComboBox, menwhile. have the Dictionary value: Person connected with three textboxes. That is, once a key is selected in the ComboBox, the corresponding value, firstname, lastname, city are shown in the three textboxes respectively? Thanks in advance!

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  • Scala match question

    - by javier
    Hello to everyone. I came across with an error on my Scala code that I cannot solve by myself (I am new at Scala). I have the following code: def myFunction(list: List[Any]): String = { var strItems : String = ""; list.foreach(item => { strItems += item match { case x:JsonSerializable => x.toJson() case y:String => ("\"" + y + "\"") case _ => item.toString } if(item != list.last) strItems += ","; }) strItems; } The error I am getting is: error: pattern type is incompatible with expected type; found : String required: Unit case y:String = ("\"" + y + "\"") Any idea why? PS: is there a more performant way to code myFunction

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  • PostSharp, Obfuscation, and IL

    - by simonc
    Aspect-oriented programming (AOP) is a relatively new programming paradigm. Originating at Xerox PARC in 1994, the paradigm was first made available for general-purpose development as an extension to Java in 2001. From there, it has quickly been adapted for use in all the common languages used today. In the .NET world, one of the primary AOP toolkits is PostSharp. Attributes and AOP Normally, attributes in .NET are entirely a metadata construct. Apart from a few special attributes in the .NET framework, they have no effect whatsoever on how a class or method executes within the CLR. Only by using reflection at runtime can you access any attributes declared on a type or type member. PostSharp changes this. By declaring a custom attribute that derives from PostSharp.Aspects.Aspect, applying it to types and type members, and running the resulting assembly through the PostSharp postprocessor, you can essentially declare 'clever' attributes that change the behaviour of whatever the aspect has been applied to at runtime. A simple example of this is logging. By declaring a TraceAttribute that derives from OnMethodBoundaryAspect, you can automatically log when a method has been executed: public class TraceAttribute : PostSharp.Aspects.OnMethodBoundaryAspect { public override void OnEntry(MethodExecutionArgs args) { MethodBase method = args.Method; System.Diagnostics.Trace.WriteLine( String.Format( "Entering {0}.{1}.", method.DeclaringType.FullName, method.Name)); } public override void OnExit(MethodExecutionArgs args) { MethodBase method = args.Method; System.Diagnostics.Trace.WriteLine( String.Format( "Leaving {0}.{1}.", method.DeclaringType.FullName, method.Name)); } } [Trace] public void MethodToLog() { ... } Now, whenever MethodToLog is executed, the aspect will automatically log entry and exit, without having to add the logging code to MethodToLog itself. PostSharp Performance Now this does introduce a performance overhead - as you can see, the aspect allows access to the MethodBase of the method the aspect has been applied to. If you were limited to C#, you would be forced to retrieve each MethodBase instance using Type.GetMethod(), matching on the method name and signature. This is slow. Fortunately, PostSharp is not limited to C#. It can use any instruction available in IL. And in IL, you can do some very neat things. Ldtoken C# allows you to get the Type object corresponding to a specific type name using the typeof operator: Type t = typeof(Random); The C# compiler compiles this operator to the following IL: ldtoken [mscorlib]System.Random call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle( valuetype [mscorlib]System.RuntimeTypeHandle) The ldtoken instruction obtains a special handle to a type called a RuntimeTypeHandle, and from that, the Type object can be obtained using GetTypeFromHandle. These are both relatively fast operations - no string lookup is required, only direct assembly and CLR constructs are used. However, a little-known feature is that ldtoken is not just limited to types; it can also get information on methods and fields, encapsulated in a RuntimeMethodHandle or RuntimeFieldHandle: // get a MethodBase for String.EndsWith(string) ldtoken method instance bool [mscorlib]System.String::EndsWith(string) call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle( valuetype [mscorlib]System.RuntimeMethodHandle) // get a FieldInfo for the String.Empty field ldtoken field string [mscorlib]System.String::Empty call class [mscorlib]System.Reflection.FieldInfo [mscorlib]System.Reflection.FieldInfo::GetFieldFromHandle( valuetype [mscorlib]System.RuntimeFieldHandle) These usages of ldtoken aren't usable from C# or VB, and aren't likely to be added anytime soon (Eric Lippert's done a blog post on the possibility of adding infoof, methodof or fieldof operators to C#). However, PostSharp deals directly with IL, and so can use ldtoken to get MethodBase objects quickly and cheaply, without having to resort to string lookups. The kicker However, there are problems. Because ldtoken for methods or fields isn't accessible from C# or VB, it hasn't been as well-tested as ldtoken for types. This has resulted in various obscure bugs in most versions of the CLR when dealing with ldtoken and methods, and specifically, generic methods and methods of generic types. This means that PostSharp was behaving incorrectly, or just plain crashing, when aspects were applied to methods that were generic in some way. So, PostSharp has to work around this. Without using the metadata tokens directly, the only way to get the MethodBase of generic methods is to use reflection: Type.GetMethod(), passing in the method name as a string along with information on the signature. Now, this works fine. It's slower than using ldtoken directly, but it works, and this only has to be done for generic methods. Unfortunately, this poses problems when the assembly is obfuscated. PostSharp and Obfuscation When using ldtoken, obfuscators don't affect how PostSharp operates. Because the ldtoken instruction directly references the type, method or field within the assembly, it is unaffected if the name of the object is changed by an obfuscator. However, the indirect loading used for generic methods was breaking, because that uses the name of the method when the assembly is put through the PostSharp postprocessor to lookup the MethodBase at runtime. If the name then changes, PostSharp can't find it anymore, and the assembly breaks. So, PostSharp needs to know about any changes an obfuscator does to an assembly. The way PostSharp does this is by adding another layer of indirection. When PostSharp obfuscation support is enabled, it includes an extra 'name table' resource in the assembly, consisting of a series of method & type names. When PostSharp needs to lookup a method using reflection, instead of encoding the method name directly, it looks up the method name at a fixed offset inside that name table: MethodBase genericMethod = typeof(ContainingClass).GetMethod(GetNameAtIndex(22)); PostSharp.NameTable resource: ... 20: get_Prop1 21: set_Prop1 22: DoFoo 23: GetWibble When the assembly is later processed by an obfuscator, the obfuscator can replace all the method and type names within the name table with their new name. That way, the reflection lookups performed by PostSharp will now use the new names, and everything will work as expected: MethodBase genericMethod = typeof(#kGy).GetMethod(GetNameAtIndex(22)); PostSharp.NameTable resource: ... 20: #kkA 21: #zAb 22: #EF5a 23: #2tg As you can see, this requires direct support by an obfuscator in order to perform these rewrites. Dotfuscator supports it, and now, starting with SmartAssembly 6.6.4, SmartAssembly does too. So, a relatively simple solution to a tricky problem, with some CLR bugs thrown in for good measure. You don't see those every day! Cross posted from Simple Talk.

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  • Change color of text within a RichTextBox in C#

    - by Addie
    I have a RichTextBox that I write a string to every time I click a Form button. The string ends with a newline so each time I add a string, it appends to the bottom of the RichTextBox. Each string begins with the string "Long" or "Short" and ends with Environment.NewLine. I'd like to color each line red if it beings with "Long" and blue if it begins with "Short". How can I do this? If you need further clarification of the question comment below.

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  • org.hibernate.HibernateException: Error while accessing enum.values(): class com.mksoft.fbautomate.d

    - by Misha Koshelev
    This error is driving me nuts!!! Caused by: java.lang.NoSuchMethodException: com.mksoft.fbautomate.domain.Account$Type.values() The same exact class works fine in a separate Groovy file. Any ideas/help much appreciated. Most confusing... http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Enum.html has no values() method! Here is my class: @Entity class Account { @Id @GeneratedValue(strategy=GenerationType.AUTO) public Long id enum Type {MYVALUE} @Enumerated(EnumType.STRING) public Type type public String email // @org.hibernate.annotations.Type(type="encryptedString") public String pass public String fullName String toString() { "type:\""+type+"\",email:\""+email+"\""+",fullName=\""+fullName+"\"" } } Thank you! Misha

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  • Passing a comparator syntax help in Java

    - by Crystal
    I've tried this a couple ways, the first is have a class that implements comparator at the bottom of the following code. When I try to pass the comparat in sortListByLastName, I get a constructor not found error and I am not sure why import java.util.*; public class OrganizeThis implements WhoDoneIt { /** Add a person to the organizer @param p A person object */ public void add(Person p) { staff.put(p.getEmail(), p); //System.out.println("Person " + p + "added"); } /** * Remove a Person from the organizer. * * @param email The email of the person to be removed. */ public void remove(String email) { staff.remove(email); } /** * Remove all contacts from the organizer. * */ public void empty() { staff.clear(); } /** * Find the person stored in the organizer with the email address. * Note, each person will have a unique email address. * * @param email The person email address you are looking for. * */ public Person findByEmail(String email) { Person aPerson = staff.get(email); return aPerson; } /** * Find all persons stored in the organizer with the same last name. * Note, there can be multiple persons with the same last name. * * @param lastName The last name of the persons your are looking for. * */ public Person[] find(String lastName) { ArrayList<Person> names = new ArrayList<Person>(); for (Person s : staff.values()) { if (s.getLastName() == lastName) { names.add(s); } } // Convert ArrayList back to Array Person nameArray[] = new Person[names.size()]; names.toArray(nameArray); return nameArray; } /** * Return all the contact from the orgnizer in * an array sorted by last name. * * @return An array of Person objects. * */ public Person[] getSortedListByLastName() { PersonLastNameComparator comp = new PersonLastNameComparator(); Map<String, Person> sorted = new TreeMap<String, Person>(comp); ArrayList<Person> sortedArrayList = new ArrayList<Person>(); for (Person s: sorted.values()) { sortedArrayList.add(s); } Person sortedArray[] = new Person[sortedArrayList.size()]; sortedArrayList.toArray(sortedArray); return sortedArray; } private Map<String, Person> staff = new HashMap<String, Person>(); public static void main(String[] args) { OrganizeThis testObj = new OrganizeThis(); Person person1 = new Person("J", "W", "111-222-3333", "[email protected]"); Person person2 = new Person("K", "W", "345-678-9999", "[email protected]"); Person person3 = new Person("Phoebe", "Wang", "322-111-3333", "[email protected]"); Person person4 = new Person("Nermal", "Johnson", "322-342-5555", "[email protected]"); Person person5 = new Person("Apple", "Banana", "123-456-1111", "[email protected]"); testObj.add(person1); testObj.add(person2); testObj.add(person3); testObj.add(person4); testObj.add(person5); System.out.println(testObj.findByEmail("[email protected]")); System.out.println("------------" + '\n'); Person a[] = testObj.find("W"); for (Person p : a) System.out.println(p); System.out.println("------------" + '\n'); a = testObj.find("W"); for (Person p : a) System.out.println(p); System.out.println("SORTED" + '\n'); a = testObj.getSortedListByLastName(); for (Person b : a) { System.out.println(b); } System.out.println(testObj.getAuthor()); } } class PersonLastNameComparator implements Comparator<Person> { public int compare(Person a, Person b) { return a.getLastName().compareTo(b.getLastName()); } } And then when I tried doing it by creating an anonymous inner class, I also get a constructor TreeMap cannot find symbol error. Any thoughts? inner class method: public Person[] getSortedListByLastName() { //PersonLastNameComparator comp = new PersonLastNameComparator(); Map<String, Person> sorted = new TreeMap<String, Person>(new Comparator<Person>() { public int compare(Person a, Person b) { return a.getLastName().compareTo(b.getLastName()); } }); ArrayList<Person> sortedArrayList = new ArrayList<Person>(); for (Person s: sorted.values()) { sortedArrayList.add(s); } Person sortedArray[] = new Person[sortedArrayList.size()]; sortedArrayList.toArray(sortedArray); return sortedArray; }

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  • Does the order of readonly variable declarations guarantee the order in which the values are set?

    - by Jason Down
    Say I were to have a few readonly variables for filepaths, would I be able to guarantee the order in which the values are assigned based on the order of declaration? e.g. readonly string basepath = @"my\base\directory\location"; readonly string subpath1 = basepath + @"\abc\def"; readonly string subpath2 = basepath + @"\ghi\klm"; Is this a safe approach or is it possible that basepath may still be the default value for a string at the time subpath1 and subpath2 make a reference to the string? I realize I could probably guarantee the order by assigning the values in a constructor instead of at the time of declaration. However, I believe this approach wouldn't be possible if I needed to declare the variables inside of a static class (e.g. Program.cs for a console application, which has a static void Main() procedure instead of a constructor).

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