Search Results

Search found 19961 results on 799 pages for 'charting control'.

Page 238/799 | < Previous Page | 234 235 236 237 238 239 240 241 242 243 244 245  | Next Page >

  • Using the hardware keyboard to simulate button press on Android

    - by Bevor
    Hello, it is difficult to test a game with the mouse pointer on android buttons. I would like to control those buttons with the hardware keyboard. Actually I don't want to control the buttons itself but I want to control the behaviour the buttons would also do. For example I have 4 buttons in the android application with "arrow up, down, left, right". I'd like to use the arrow buttons of my hardware keyboard to control the same. How can I do that? Actually the question is, where can I set the Listener? I tried something in my activity. I set this listener to the application button: button.setOnKeyListener(new OnKeyListener() { @Override public boolean onKey(View v, int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) //scroll down return true; } }); The behaviour is the following: I can't scroll down with my hardware keyboard but with the hardware keyboard I can select the android buttons (they will be highlighted when I move on any button). After I selected the button with the Listener I can't select any other button anymore but then the Listener comes into force. Now I can scroll down with the hardware keyboard arrow down button. I would like to achieve this behaviour without selecting any button. So I thought about setting the listener to the layout container or any other layout but this has no effect. Is there any other approach to achieve this?

    Read the article

  • Nest input inside f.label ( rails form generation )

    - by Mike
    I want to use the f.label method to create my form element labels, however - i want to have the form element nested inside the label. Is this possible? -- From W3C -- To associate a label with another control implicitly, the control element must be within the contents of the LABEL element. In this case, the LABEL may only contain one control element. The label itself may be positioned before or after the associated control. In this example, we implicitly associate two labels with two text input controls: <FORM action="..." method="post"> <P> <LABEL> First Name <INPUT type="text" name="firstname"> </LABEL> <LABEL> <INPUT type="text" name="lastname"> Last Name </LABEL> </P> </FORM>

    Read the article

  • MySQL Need some help with a query

    - by Jules
    I'm trying to fix some data by adding a new field. I have a backup from a few months ago and I have restored this database to my server. I'm looking at table called pads, its primary key is PadID and the field of importance is called RemoveMeDate. In my restored (older) database there is less records with an actual date set in RemoveMeDate. My control date is 2001-01-01 00:00:00 meaning that the record is not hidden aka visible. What I need to do is select all the records from the older database / table with the control date and join with those from the newer db /table where the control date is not set. I hope I've explained that correctly. I'll try again, with numbers. I have 80,000 visible records in the older table (with control date set) and 30,000 in the newer db/table. I need to select the 50,000 from the old database, to perform an update query. Heres my query, which I'd can't get to work as I'd like. jules-fix-reasons is the old database, jules is the newer one. select p.padid from `jules-fix-reasons`.`pads` p JOIN `jules`.`pads` ON p.padid = `jules`.`pads`.`PadID` where p.RemoveMeDate <> '2001-01-01 00:00:00' AND `jules`.`pads`.RemoveMeDate = '2001-01-01 00:00:00'

    Read the article

  • Aligning inputs on bootstrap using the Fluid Grid System

    - by sguha
    I am creating a form that requires the user to input their name and email address. The first line of the form has two inputs side by side for each part of the name and the 2nd line has one input for the email address that should be the same width as the first line combined. I'm trying to use the fluid grid system but can't line up the 2nd row with the first. <form action="/subscriptions" method="post"> <fieldset> <div class="control-group"> <label class="control-label" for="name">Name</label> <div class="controls row-fluid"> <input class="span2" id="first_name" name="first_name" placeholder="First" required="required" type="text"> <input class="span2" id="last_name" name="last_name" placeholder="Last" required="required" type="text"> </div> </div> <div class="control-group"> <label class="control-label" for="email">Email</label> <div class="controls row-fluid"> <input class="span4" id="email" name="email" type="email"> </div> </div> </fieldset> </form>? http://jsfiddle.net/sguha095/v4amX/

    Read the article

  • Group panel of WPF ListBox

    - by rulestein
    I have a listbox that is grouping the items with a GroupStyle. I would like add a control at the bottom of the stackpanel that holds all of the groups. This additional control needs to be part of the scrolling content so that the user would scroll to the bottom of the list to see the control. If I were using a listbox without the groups, this task would be easy by modifying the ListBox template. However, with the items grouped, the ListBox template seems to only apply on a per group basis. I can modify the GroupStyle.Panel, but that doesn't allow me to add items to that panel. <ListBox> <ListBox.ItemsPanel> <ItemsPanelTemplate> <WrapPanel/> </ItemsPanelTemplate> </ListBox.ItemsPanel> <ListBox.GroupStyle> <GroupStyle> <GroupStyle.Panel> <ItemsPanelTemplate> <VirtualizingStackPanel/> **<----- I would like to add a control to this stackpanel** </ItemsPanelTemplate> </GroupStyle.Panel> <GroupStyle.ContainerStyle> <Style TargetType="{x:Type GroupItem}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type GroupItem}"> <Grid> <ItemsPresenter /> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style> </GroupStyle.ContainerStyle> </GroupStyle> </ListBox.GroupStyle> This should give an idea of what I need to do:

    Read the article

  • ControlCollection extension method optimization

    - by Johan Leino
    Hi, got question regarding an extension method that I have written that looks like this: public static IEnumerable<T> FindControlsOfType<T>(this ControlCollection instance) where T : class { T control; foreach (Control ctrl in instance) { if ((control = ctrl as T) != null) { yield return control; } foreach (T child in FindControlsOfType<T>(ctrl.Controls)) { yield return child; } } } public static IEnumerable<T> FindControlsOfType<T>(this ControlCollection instance, Func<T, bool> match) where T : class { return FindControlsOfType<T>(instance).Where(match); } The idea here is to find all controls that match a specifc criteria (hence the Func<..) in the controls collection. My question is: Does the second method (that has the Func) first call the first method to find all the controls of type T and then performs the where condition or does the "runtime" optimize the call to perform the where condition on the "whole" enumeration (if you get what I mean). secondly, are there any other optimizations that I can do to the code to perform better. An example can look like this: var checkbox = this.Controls.FindControlsOfType<MyCustomCheckBox>( ctrl => ctrl.CustomProperty == "Test" ) .FirstOrDefault();

    Read the article

  • WPF: Binding an integer to a TextBlock with TemplateBinding

    - by haagel
    I have a custom control in WPF. In this I have a DependencyProperty of the type integer. In the template for the custom control I have a TextBlock, I and would like to show the value of the integer in the TextBlock. But I can't get it to work. I'm using TemplateBinding. If I use the same code but change the type of the DependencyProperty to string it works fine. But I really want it to be an integer for the rest of my application to work. How can I do this? I've written simplified code that shows the problem. First the custom control: public class MyCustomControl : Control { static MyCustomControl() { DefaultStyleKeyProperty.OverrideMetadata(typeof(MyCustomControl), new FrameworkPropertyMetadata(typeof(MyCustomControl))); MyIntegerProperty = DependencyProperty.Register("MyInteger", typeof(int), typeof(MyCustomControl), new FrameworkPropertyMetadata(0)); } public int MyInteger { get { return (int)GetValue(MyCustomControl.MyIntegerProperty); } set { SetValue(MyCustomControl.MyIntegerProperty, value); } } public static readonly DependencyProperty MyIntegerProperty; } And this is my default template: <Style TargetType="{x:Type local:MyCustomControl}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type local:MyCustomControl}"> <Border BorderThickness="1" CornerRadius="4" BorderBrush="Black" Background="Azure"> <StackPanel Orientation="Vertical"> <TextBlock Text="{TemplateBinding MyInteger}" HorizontalAlignment="Center" /> </StackPanel> </Border> </ControlTemplate> </Setter.Value> </Setter> </Style> What am I doing wrong? Thanks // David

    Read the article

  • WPF : Command routing for Keyboard shortcuts.

    - by Sprotty
    Basically I want to create a keyboard shortcut which is valid within the scope of a window, and not just enabled when focus is within the control that binds it. in more detail.... I have a window which has 3 controls a toolbar textbox Custom Control The toolbar has a button bound to the Command CustomCommands.CmdA and linked to 'Ctrl-T'. My Custom Control can process CmdA. When I run the app and click on my custom control CmdA is enabled and works fine. Also Ctrl-T cause the command to fire. However when I select the text box, my custom command CmdA becomes disabled. I can rectify this by setting the command target for CmdA's button. Now when I select the textBox, CmdA is still enabled. But the Keyboard shortcut Ctrl-T does nothing. Is there any easy way to change the scope of keyboard shortcuts? Or do I need to catch the keypress somewhere lower down, and work out which Command it relates to and route it myself (if so is there a framework within which to do this?) Many Thanks Simon

    Read the article

  • Custom Controls Properties - C# , Forms - :(

    - by user353600
    Hi I m adding custom control to my flowlayoutpanel , its a sort of forex data , refresh every second , so on each timer tick , i m adding a control , changing controls button text , then adding it to flowlayout panel , i m doing it at each 100ms timer tick , it takeing tooo much CPU , here is my custom Control . public partial class UserControl1 : UserControl { public UserControl1() { InitializeComponent(); } private void UserControl1_Load(object sender, EventArgs e) { } public void displaydata(string name , string back3price , string back3 , string back2price , string back2 , string back1price , string back1 , string lay3price , string lay3 , string lay2price , string lay2 , string lay1price , string lay1 ) { lblrunnerName.Text = name.ToString(); btnback3.Text = back3.ToString() + "\n" + back3price.ToString(); btnback2.Text = back2.ToString() + "\n" + back2price.ToString(); btnback1.Text = back1.ToString() + "\n" + back1price.ToString(); btnlay1.Text = lay1.ToString() + "\n" + lay1price.ToString(); btnlay2.Text = lay2.ToString() + "\n" + lay2price.ToString(); btnlay3.Text = lay3.ToString() + "\n" + lay3price.ToString(); } and here is how i m adding control; private void timer1_Tick(object sender, EventArgs e) { localhost.marketData[] md; md = ser.getM1(); flowLayoutPanel1.Controls.Clear(); foreach (localhost.marketData item in md) { UserControl1 ur = new UserControl1(); ur.Name = item.runnerName + item.runnerID; ur.displaydata(item.runnerName, item.back3price, item.back3, item.back2price, item.back2, item.back1price, item.back1, item.lay3price, item.lay3, item.lay2price, item.lay2, item.lay1price, item.lay1); flowLayoutPanel1.SuspendLayout(); flowLayoutPanel1.Controls.Add(ur); flowLayoutPanel1.ResumeLayout(); } } now its happing on 10 times on each send , taking 60% of my Core2Duo cpu . is there any other way , i can just add contols first time , and then change the text of cutom controls buttons on runtime on each refresh or timer tick i m using c# .Net

    Read the article

  • Partial class or "chained inheritance"

    - by Charlie boy
    Hi From my understanding partial classes are a bit frowned upon by professional developers, but I've come over a bit of an issue; I have made an implementation of the RichTextBox control that uses user32.dll calls for faster editing of large texts. That results in quite a bit of code. Then I added spellchecking capabilities to the control, this was made in another class inheriting RichTextBox control as well. That also makes up a bit of code. These two functionalities are quite separate but I would like them to be merged so that I can drop one control on my form that has both fast editing capabilities and spellchecking built in. I feel that simply adding the code form one class to the other would result in a too large code file, especially since there are two very distinct areas of functionality, so I seem to need another approach. Now to my question; To merge these two classes should I make the spellchecking RichTextBox inherit from the fast edit one, that in turn inherits RichTextBox? Or should I make the two classes partials of a single class and thus making them more “equal” so to speak? This is more of a question of OO principles and exercise on my part than me trying to reinvent the wheel, I know there are plenty of good text editing controls out there. But this is just a hobby for me and I just want to know how this kind of solution would be managed by a professional. Thanks!

    Read the article

  • C#: Non-constructed generics as properties (eg. List<T>)

    - by Dav
    The Problem It's something I came across a while back and was able to work around it somehow. But now it came back, feeding on my curiosity - and I'd love to have a definite answer. Basically, I have a generic dgv BaseGridView<T> : DataGridView where T : class. Constructed types based on the BaseGridView (such as InvoiceGridView : BaseGridView<Invoice>) are later used in the application to display different business objects using the shared functionality provided by BaseGridView (like virtual mode, buttons, etc.). It now became necessary to create a user control that references those constructed types to control some of the shared functionality (eg. filtering) from BaseGridView. I was therefore hoping to create a public property on the user control that would enable me to attach it to any BaseGridView in Designer/code: public BaseGridView<T> MyGridView { get; set; }. The trouble is, it doesn't work :-) When compiled, I get the following message: The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?) Solutions? I realise I could extract the shared functionality to an interface, mark BaseGridView as implementing that interface, and then refer to the created interface in my uesr control. But I'm curious if there exists some arcane C# command/syntax that would help me achieve what I want - without polluting my solution with an interface I don't really need :-)

    Read the article

  • How can I use a meter-style progress bar?

    - by Yadyn
    In Vista/7, the Windows Explorer shell window makes use of a special kind of static progress bar to display hard drive space. With default styles, this bar is blue colored and non-animated. It also turns red colored when it gets close to being full (low disk space). Using messaging, I can tell the Windows Forms ProgressBar control to update its state to Paused and Error (yellow and red colored, respectively), which works fine, but these are still specific to progress. In the Windows User Experience Guidelines, it specifically points out this "meter" variant of the Progress Bar: This pattern isn't a progress bar, but it is implemented using the progress bar control. Meters have a distinct look to differentiate them from true progress bars. They say it "is implemented using the progress bar control", so... how? What message could I send to the control to have it behave this way? I've seen that you can send messages for setting the bar color, but the documentation says these calls are ignored when visual styles are enabled. Nothing else in the Windows API documentation for raw ProgressBar controls seemed to suggest a way to do this. Am I just stuck making a custom drawn bar? I'd really like to utilize the OS whenever possible so that the application will appear consistent throughout different OS versions. I realize that pre-Vista versions probably won't support this, though. I'm looking for a Windows Forms solution, but I wonder if it is even exposed at all via Win32 API.

    Read the article

  • Why do I get this strange output behavior?

    - by WilliamKF
    I have the following program test.cc: #include <iostream> unsigned char bogus1[] = { // Changing # of periods (0x2e) changes output after periods. 0x2e, 0x2e, 0x2e, 0x2e }; unsigned int bogus2 = 1816; // Changing this value changes output. int main() { std::clog << bogus1; } I build it with: g++ -g -c -o test.o test.cc; g++ -static-libgcc -o test test.o Using g++ version 3.4.6 I run it through valgrind and nothing is reported wrong. However the output has two extra control characters and looks like this: .... Thats a control-X and a control-G at the end. If you change the value of bogus2 you get different control characters. If you change the number of periods in the array the issue goes away or changes. I suspect it is a memory corruption bug in the compiler or iostream package. What is going on here?

    Read the article

  • ASP.Net event only being raised every other time?

    - by eftpotrm
    I have an ASP.Net web user control which represents a single entry in a list. To allow users to reorder the items, each item has buttons to move the item up or down the list. Clicking on one of these raises an event to the parent page, which then shuffles the items in the placeholder control. Code fragments from the list entry: Public Event UpClicked As System.EventHandler Protected Sub btnUp_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnUp.Click RaiseEvent UpClicked(Me, New EventArgs()) End Sub And the parent container: rem (within the code to add an individual item to the placeholder) AddHandler l_oItem.UpClicked, AddressOf UpClicked Protected Sub UpClicked(ByVal sender As Object, ByVal e As EventArgs) MoveItem(DirectCast(sender, ScriptListItem), -1) End Sub It originally looked in testing like every other time the value for sender (verified by its properties) that reaches UpClicked is of an adjacent ListItem, not the one I've just clicked on - the first click is always wrong, then the second for the correct control. At present, testing appears to show that the button's click event is just being ignored every other time through. Breakpoints on the click events within the control simply aren't being hit, though the events are definitely being established. Why?

    Read the article

  • plot a line graph in vb.net

    - by Husna5207
    this is my function for plotting a graph in vb.net how I'm going to replace the ("Jon", 10),("Jordan", 30) with a value that i search from database ? Private Sub chart_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chart_btn.Click Chart1.Series("Student").Points.AddXY("Jon", 10) Chart1.Series("Student").Points.AddXY("Jon", 10) Chart1.Series("Student").ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Bar End Sub

    Read the article

  • What's the easiest way to add Java servlets to a WAMP configured machine?

    - by Rhubarb
    I have WAMP installed on my local machine and am looking to serve up charts using jFree's Eastwood charting, which requires me to use servlets. So basically I will insert images with src tags that have URLs pointing to my servlet on the same machine. What's the easiest way to enable servlets on the same machine? Do I need to install a servlet server on a different port? Or is there a way to integrate it into WAMP?

    Read the article

  • In Silverlight, what structures, aside of the ListBox, can be used for binding?

    - by Aidenn
    I need to simply provide the content of a property to a custom User Control in Silverlight. My control is something like this: <UserControl x:Class="SilverlightApplication.Header" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" d:DesignWidth="300" d:DesignHeight="120"> <Grid x:Name="Header_Layout"> <StackPanel x:Name="hiHeaderContent" Width="Auto" Margin="73,8,8,8"> <TextBlock x:Name="User:" Text="{Binding name}" /> </StackPanel> </Grid> I try to use this User Control from another control where I try to pass the parameter "name" to the previous UserControl ("Header"). I don't need to create a "ListBox" as I will only have 1 header, so I try to avoid doing: <ListBox x:Name="HeaderListBox" Grid.Row="0"> <ListBox.ItemTemplate> <DataTemplate> <SilverlightApplication:Header/> </DataTemplate> </ListBox.ItemTemplate> </ListBox> in order to send the "User" account using: HeaderListBox.ItemsSource = name; Is there any other structure I can use instead of the ListBox to pass the parameter just once? It won't be a list, it's just a header... Thank you!

    Read the article

  • Google Maps Controls panel size is displayed wrong

    - by Andrea Giachetto
    I have a weird problem with Google Maps Control. I've tested in a blank page my custom maps with custom markers and everything seems to be ok, also with the control panel. When I tried to import all my code in the page I'm working with ( I use a full screen fluid grid system ) the control panel is displayed with strange size. I tried everything for disable/enable the ui of the Google Maps but the problem remain. The code of my maps are exactly the same, both in my blank page and in my site, but in the site the ui control panel is displayed very strange. Here's the code: <div id="map_canvas2" style="height: 580px; width: 100%;"></div> <script> var image = 'path/to/your/image.png'; var mapOptions = { zoom: 17, center: new google.maps.LatLng(45.499290, 12.621510), mapTypeId: google.maps.MapTypeId.ROADMAP, scrollwheel: false } var map = new google.maps.Map(document.getElementById('map_canvas2'), mapOptions); var myPos = new google.maps.LatLng(45.499290,12.621510); var myMarker = new google.maps.Marker({position: myPos, map: map, icon: 'http://www.factory42.it/jtaca/wordpress/wp-content/uploads/2014/06/pin-map.png' }); </script> </div> Here's an img: http://www.factory42.it/jtaca/wordpress/wp-content/uploads/2014/06/img-maps.png

    Read the article

  • MS Access Form - Horizontal Anchor Affecting Data Update

    - by nicholas
    Running Access 2007 with a databound form. The form Record Source is set to a query, and all fields in the form have a defined Control Source; nothing fancy, just field names. The form is a Single form with record navigation buttons which perform a "Next Record" and "Previous Record" actions. As I navigate the records the controls in the header update correctly. However, if I change a control Horizontal Anchor property to "Right" the fields no longer update on record navigation. This is observed for both text box and combo box controls. I can switch the anchoring back to "Left" and the updating works as it should. Is there some reason anchoring would affect a control updating of in an Access form? Or is this a bug that has been observed before? The only workaround I can think of is to assign the control text/value property in the form OnCurrent event, but this seems somewhat sloppy. Am I missing something here?

    Read the article

  • How to implement a search page which shows results on the same page?

    - by Andrew
    I'm using ASP.NET MVC 2 for the first time on a project at work and am feeling like a bit of a noob. I have a page with a customer search control/partial view. The control is a textbox and a button. You enter a customer id into the textbox and hit search. The page then "refreshes" and shows the customer details on the same page. In other words, the customer details appear below the customer search control. This is so that if the customer isn't the right one, the user can search again without hitting back in the browser. Or, perhaps they mistyped the customer id and need to try again. I want the URL to look like this: /Customer/Search/1 Obviously, this follows the default route in the project. Now, if I type the URL above directly into my browser, it works fine. However, when I then use the search control on that page to search for say customer 2, the page refreshes with the correct customer details but the URL does not change! It stays as /Customer/Search/1 When I want it to be /Customer/Search/2 How can I get it to change to the correct URL? I am only using the default route in Global.asax. My Search method looks like this: <AcceptVerbs(HttpVerbs.Get)> _ Function Search(ByVal id As String) As ActionResult Dim customer As Customer = New CustomerRepository().GetById(id) Return View("SearchResult", customer) End Function

    Read the article

  • How to change name attribut value from twig

    - by taieb baccouch
    I am using Symfony version 2.3 and twig version 1.0. and I'm trying to change the name attribut value. Here is my code : <div class="control-group"> {{ form_label(form.menuTitle, null, {'label_attr': {'class': 'control-label'}}) }} {{ form_errors(form.menuTitle)}} <div class="controls"> <div class="span12"> {{ form_widget(form.menuTitle, {'attr': {'class': 'span6'}}) }} </div> </div> </div> The rendering code : <div class="control-group"> <label class="control-label required" for="smart_contactbundle_contact_menuTitle">Menu title</label> <div class="controls"> <div class="span12"> <input type="text" id="smart_contactbundle_contact_menuTitle" name="smart_contactbundle_contact[menuTitle]" required="required" maxlength="255" class="span6"> </div> </div> </div> I want to change name="smart_contactbundle_contact[menuTitle]" to name="menuTitle"

    Read the article

  • Substitute User Controls on Failure

    - by Brian
    Recently, I had a user control I was developing throw an exception. I know what caused the exception, but this issue got me thinking. If I have a user control throw an exception for whatever reason and I wish to replace that usercontrol with something else (e.g. an error saying, "Sorry, this part of the page broke.") and perhaps log the error, what would be a good way to do it that could be done independently of what the user control is or does (i.e. I'm not saying what the user control does/is, because I want an answer where that is irrelevant). Code sample: <asp:TableRow VerticalAlign="Top" HorizontalAlign="Left"> <asp:TableCell> <UR:MyUserControl ID="MyUserControl3" runat="server" FormatString="<%$ AppSettings:RVUC %>" ConnectionString="<%$ ConnectionStrings:WPDBC %>" Title="CO" /> </asp:TableCell> <asp:TableCell> <UR:MyUserControl ID="MyUserControl4" runat="server" FormatString="<%$ AppSettings:RVUA %>" ConnectionString="<%$ ConnectionStrings:WPDBA %>" Title="IEAO" /> </asp:TableCell> </asp:TableRow>

    Read the article

  • How to focus next field if user clicked on the link?

    - by LA_
    I have a number of fields with labels-links like below: <div class="control-group"> <label class="control-label" for="some-id-1"><a href="http://example.com/some-id-1" target="_blank">Text1</a></label> <div class="controls"> <input type="text" id="some-id-1" name="some-id-1"><br> </div> </div> <div class="control-group"> <label class="control-label" for="some-id-2"><a href="http://example.com/some-id-2" target="_blank">Text2</a></label> <div class="controls"> <input type="text" id="some-id-2" name="some-id-2"><br> </div> </div> If user clicks on the link, how can I focus according field (without preventing default action)? I.e. if user clicks on Text1, then I should open http://example.com/some-id-1 in new window and set focus at input with id some-id-1.

    Read the article

  • HttpContext.Items and Server.Transfer/Execute

    - by Rick Strahl
    A few days ago my buddy Ben Jones pointed out that he ran into a bug in the ScriptContainer control in the West Wind Web and Ajax Toolkit. The problem was basically that when a Server.Transfer call was applied the script container (and also various ClientScriptProxy script embedding routines) would potentially fail to load up the specified scripts. It turns out the problem is due to the fact that the various components in the toolkit use request specific singletons via a Current property. I use a static Current property tied to a Context.Items[] entry to handle this type of operation which looks something like this: /// <summary> /// Current instance of this class which should always be used to /// access this object. There are no public constructors to /// ensure the reference is used as a Singleton to further /// ensure that all scripts are written to the same clientscript /// manager. /// </summary> public static ClientScriptProxy Current { get { if (HttpContext.Current == null) return new ClientScriptProxy(); ClientScriptProxy proxy = null; if (HttpContext.Current.Items.Contains(STR_CONTEXTID)) proxy = HttpContext.Current.Items[STR_CONTEXTID] as ClientScriptProxy; else { proxy = new ClientScriptProxy(); HttpContext.Current.Items[STR_CONTEXTID] = proxy; } return proxy; } } The proxy is attached to a Context.Items[] item which makes the instance Request specific. This works perfectly fine in most situations EXCEPT when you’re dealing with Server.Transfer/Execute requests. Server.Transfer doesn’t cause Context.Items to be cleared so both the current transferred request and the original request’s Context.Items collection apply. For the ClientScriptProxy this causes a problem because script references are tracked on a per request basis in Context.Items to check for script duplication. Once a script is rendered an ID is written into the Context collection and so considered ‘rendered’: // No dupes - ref script include only once if (HttpContext.Current.Items.Contains( STR_SCRIPTITEM_IDENTITIFIER + fileId ) ) return; HttpContext.Current.Items.Add(STR_SCRIPTITEM_IDENTITIFIER + fileId, string.Empty); where the fileId is the script name or unique identifier. The problem is on the Transferred page the item will already exist in Context and so fail to render because it thinks the script has already rendered based on the Context item. Bummer. The workaround for this is simple once you know what’s going on, but in this case it was a bitch to track down because the context items are used in many places throughout this class. The trick is to determine when a request is transferred and then removing the specific keys. The first issue is to determine if a script is in a Trransfer or Execute call: if (HttpContext.Current.CurrentHandler != HttpContext.Current.Handler) Context.Handler is the original handler and CurrentHandler is the actual currently executing handler that is running when a Transfer/Execute is active. You can also use Context.PreviousHandler to get the last handler and chain through the whole list of handlers applied if Transfer calls are nested (dog help us all for the person debugging that). For the ClientScriptProxy the full logic to check for a transfer and remove the code looks like this: /// <summary> /// Clears all the request specific context items which are script references /// and the script placement index. /// </summary> public void ClearContextItemsOnTransfer() { if (HttpContext.Current != null) { // Check for Server.Transfer/Execute calls - we need to clear out Context.Items if (HttpContext.Current.CurrentHandler != HttpContext.Current.Handler) { List<string> Keys = HttpContext.Current.Items.Keys.Cast<string>().Where(s => s.StartsWith(STR_SCRIPTITEM_IDENTITIFIER) || s == STR_ScriptResourceIndex).ToList(); foreach (string key in Keys) { HttpContext.Current.Items.Remove(key); } } } } along with a small update to the Current property getter that sets a global flag to indicate whether the request was transferred: if (!proxy.IsTransferred && HttpContext.Current.Handler != HttpContext.Current.CurrentHandler) { proxy.ClearContextItemsOnTransfer(); proxy.IsTransferred = true; } return proxy; I know this is pretty ugly, but it works and it’s actually minimal fuss without affecting the behavior of the rest of the class. Ben had a different solution that involved explicitly clearing out the Context items and replacing the collection with a manually maintained list of items which also works, but required changes through the code to make this work. In hindsight, it would have been better to use a single object that encapsulates all the ‘persisted’ values and store that object in Context instead of all these individual small morsels. Hindsight is always 20/20 though :-}. If possible use Page.Items ClientScriptProxy is a generic component that can be used from anywhere in ASP.NET, so there are various methods that are not Page specific on this component which is why I used Context.Items, rather than the Page.Items collection.Page.Items would be a better choice since it will sidestep the above Server.Transfer nightmares as the Page is reloaded completely and so any new Page gets a new Items collection. No fuss there. So for the ScriptContainer control, which has to live on the page the behavior is a little different. It is attached to Page.Items (since it’s a control): /// <summary> /// Returns a current instance of this control if an instance /// is already loaded on the page. Otherwise a new instance is /// created, added to the Form and returned. /// /// It's important this function is not called too early in the /// page cycle - it should not be called before Page.OnInit(). /// /// This property is the preferred way to get a reference to a /// ScriptContainer control that is either already on a page /// or needs to be created. Controls in particular should always /// use this property. /// </summary> public static ScriptContainer Current { get { // We need a context for this to work! if (HttpContext.Current == null) return null; Page page = HttpContext.Current.CurrentHandler as Page; if (page == null) throw new InvalidOperationException(Resources.ERROR_ScriptContainer_OnlyWorks_With_PageBasedHandlers); ScriptContainer ctl = null; // Retrieve the current instance ctl = page.Items[STR_CONTEXTID] as ScriptContainer; if (ctl != null) return ctl; ctl = new ScriptContainer(); page.Form.Controls.Add(ctl); return ctl; } } The biggest issue with this approach is that you have to explicitly retrieve the page in the static Current property. Notice again the use of CurrentHandler (rather than Handler which was my original implementation) to ensure you get the latest page including the one that Server.Transfer fired. Server.Transfer and Server.Execute are Evil All that said – this fix is probably for the 2 people who are crazy enough to rely on Server.Transfer/Execute. :-} There are so many weird behavior problems with these commands that I avoid them at all costs. I don’t think I have a single application that uses either of these commands… Related Resources Full source of ClientScriptProxy.cs (repository) Part of the West Wind Web Toolkit Static Singletons for ASP.NET Controls Post © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

    Read the article

< Previous Page | 234 235 236 237 238 239 240 241 242 243 244 245  | Next Page >