What is the difference betweeen the following:

 - [SelectedItem][1]
 - [SelectedValue][2]
 - [SelectedValuePath][3]

All these dependency properties are defined in [Selector][4] class. I often confuse `SelectedItem` with `SelectedValue` , and `SelectedValue` with `SelectedValuePath`. 

I would like to know the difference between them, and also when do we use them, especially `SelectedValue` and `SelectedValuePath`. Please explain their *use* with some simple examples.

[1]:http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector.selecteditem.aspx
[2]:http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector.selectedvalue.aspx
[3]:http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector.selectedvaluepath.aspx
[4]:http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector_properties.aspx

Difference between SelectedItem, SelectedValue and SelectedValuePath

If I call `SelectAll` from a `GotFocus` event handler, it doesn&#39;t work with the mouse - the selection disappears as soon as mouse is released.

EDIT: People are liking Donnelle&#39;s answer, I&#39;ll try to explain why I did not like it as much as the accepted answer.

 - It is more complex, while the accepted answer does the same thing in a simpler way.
 - The usability of accepted answer is better. When you click in the middle of the text, text gets unselected when you release the mouse allowing you to start editing instantly, and if you still want to select all, just press the button again and this time it will not unselect on release. Following Donelle&#39;s recipe, if I click in the middle of text, I have to click second time to be able to edit. If I click somewhere within the text versus outside of the text, this most probably means I want to start editing instead of overwriting everything.

How to automatically select all text on focus in WPF TextBox?

Given a StackPanel:

    &lt;StackPanel&gt;
      &lt;TextBox Height=&quot;30&quot;&gt;Apple&lt;/TextBox&gt;
      &lt;TextBox Height=&quot;80&quot;&gt;Banana&lt;/TextBox&gt;
      &lt;TextBox Height=&quot;120&quot;&gt;Cherry&lt;/TextBox&gt;
    &lt;/StackPanel&gt;

What&#39;s the best way to space out the child elements so that there are equally-sized gaps between them, even though the child elements themselves are of different sizes? Can it be done without setting properties on each of the individual children?

How do I space out the child elements of a StackPanel?

I want to pass an enum value as command parameter in WPF, using something like this:

    &lt;Button 
        x:Name=&quot;uxSearchButton&quot; 
        Command=&quot;{Binding Path=SearchMembersCommand}&quot; 
        CommandParameter=&quot;SearchPageType.First&quot;
        Content=&quot;Search&quot;&gt;
    &lt;/Button&gt;

`SearchPageType` is an enum and this is to know from which button search command is invoked.

Is this possible in WPF, or how can you pass an enum value as command parameter?

Passing an enum value as command parameter from XAML

This is a community wiki list of Windows Phone 7 resources.  Feel free to edit/add/etc.

When posting, please use the friendly format of  
`[Actual Name of resource with a link]`  
*not*  
`[some long URL with no meaning unless I click on it]`

**General Information**&lt;br /&gt;
[App hub - central place for windows phone/xbox development tools/tutorials/info][1]&lt;br /&gt;
[Windows Phone Home][2]  
[Windows Phone Team blog][3]&lt;br /&gt;
[Programming Guide][4] &lt;br /&gt;
[Class Library Reference][5]&lt;br /&gt;
[Microsoft Patterns &amp; Practices: Windows Phone 7 Developer Guide][6]

**Blogs**&lt;br /&gt;
[Den by default: Windows Phone 7][7]&lt;br /&gt;
[.NET Zone: Windows Phone 7][8]&lt;br /&gt;
[Shawn Wildermuth: Windows Phone 7][9]&lt;br /&gt;
[Jeff Blankenburg: 31 Days of Windows Phone][10]&lt;/br /&gt;

**Articles**&lt;br /&gt;
[Building a Windows Phone 7 Puzzle Game][11]  
[Windows Phone 7 View Model Style Video Player][12]  
[Perst - a database for Windows Phone 7 Silverlight][13]  
Understanding the Windows Phone Application Execution Model, Tombstoning, Launcher and Choosers:  
[(part1)][14] [(part2)][15]  [(part3)][16]  
[Performance Tips when creating WP7 apps][17]  
[Windows Phone 7 Live Tile Schedules – How to execute instant Live Tile updates][18]&lt;br /&gt;
[Tips to get your Application in the Windows Phone 7 Marketplace ASAP][19]&lt;br /&gt;
[Checking for Network connectivity in Windows Phone 7 SDK][20]&lt;br /&gt;
[Windows Phone 7.1: a Quick Start][21]&lt;br /&gt;
[A Simple Multi-Page Windows Phone 7 Phonegap Example][22]&lt;br /&gt;

**Books**&lt;br /&gt;
[Programming Windows Phone 7][23]&lt;br /&gt;
[Professional Windows Phone 7 Application Development][24]&lt;br /&gt;
[Pro Windows Phone 7 Development][25]&lt;br /&gt;
[Beginning Windows Phone 7 Development][26]&lt;br /&gt;
[Learning Windows Phone Programming][27]&lt;br /&gt;
[Windows Phone 7 Game Development][28]&lt;br /&gt;
[Windows Phone 7 Application Development][29]&lt;br /&gt;
[101 Windows Phone 7 Apps, Volume I: Developing Apps 1-50][30]&lt;br/&gt;
[101 Windows Phone 7 Apps, Volume II: Developing Apps 51-101 (Fall 2011)][31]&lt;br/&gt;

**Podcasts**&lt;br /&gt;
[Charlie Kindel on Windows Phone 7][32]  
[Daniel Egan talks Windows Phone 7 Live at Launch][33]  
[Windows Phone 7 Series - The Developer Experience with Charlie Kindel][34]  
[Charles Petzold on Windows Phone 7 Series][35]  

**Videos**&lt;br /&gt;
[Windows Phone 7 Jump Start sessions][36]&lt;br /&gt;
[Colin Melia on Windows Phone 7][37]   
[Channel9 Content for WIndows Phone][38]  

**Developer Tools**&lt;br /&gt;
[8 Must-Have Tools for Windows Phone 7 Development][39]&lt;br /&gt;
[Windows Phone Developer Tools RTW][40]&lt;br /&gt;
[EQATEC Profiler for Windows Phone 7][41]&lt;br /&gt;
[BugSense, bug tracking for Windows Phone 7][42]&lt;br /&gt;

**Frameworks**&lt;br /&gt;
[OpenNETCF.IoC Framework][43]&lt;br /&gt;
[Autofac for WP7][44]&lt;br /&gt;
[Microsoft Silverlight Analytics Framework][45]&lt;br/&gt;
[MVVM Light Toolkit][46]&lt;br/&gt;
[Columbus: Windows Phone 7 MVC framework][47]&lt;br/&gt;
[Windows Phone MVP][48]&lt;br /&gt;
[Caliburn.Micro - MVVM framework strongly based on conventions][49]&lt;br /&gt;


  [1]: http://create.msdn.com/en-US
  [2]: http://www.microsoft.com/windowsphone/en-us/default.aspx
  [3]: http://windowsteamblog.com/Windows_Phone/
  [4]: http://msdn.microsoft.com/en-us/library/ff402551(v=VS.92).aspx
  [5]: http://msdn.microsoft.com/en-us/library/ff626516(v=VS.92).aspx
  [6]: http://msdn.microsoft.com/en-us/library/gg490765.aspx
  [7]: http://dennisdel.com/?tag=windows-phone-7
  [8]: http://dotnet.dzone.com/category/tags/windows-phone-7-0
  [9]: http://wildermuth.com/tags/Windows%20Phone
  [10]: http://jeffblankenburg.com/31daysofwp7/
  [11]: http://www.codeproject.com/KB/windows-phone-7/WindowsPhoneGame.aspx
  [12]: http://www.codeproject.com/KB/windows-phone-7/Wp7ViewModel.aspx
  [13]: http://mobileworld.appamundi.com/blogs/andywigley/archive/2010/06/07/perst-a-database-for-windows-phone-7-silverlight.aspx
  [14]: http://windowsteamblog.com/windows_phone/b/wpdev/archive/2010/07/15/understanding-the-windows-phone-application-execution-model-tombstoning-launcher-and-choosers-and-few-more-things-that-are-on-the-way-part-1.aspx
  [15]: http://windowsteamblog.com/windows_phone/b/wpdev/archive/2010/07/16/understanding-the-windows-phone-application-execution-model-tombstoning-launcher-and-choosers-and-few-more-things-that-are-on-the-way-part-2.aspx
  [16]: http://windowsteamblog.com/windows_phone/b/wpdev/archive/2010/07/20/understanding-the-windows-phone-application-execution-model-tombstoning-launcher-and-more-part-3.aspx
  [17]: http://www.windowsphonegeek.com/articles/Performance-Tips-when-creating-WP7-apps
  [18]: http://www.diaryofaninja.com/blog/2011/04/03/windows-phone-7-live-tile-schedules-ndash-executing-instant-live-tile-updates
  [19]: http://www.diaryofaninja.com/blog/2011/01/18/tips-to-get-your-application-in-the-windows-phone-7-marketplace-asap
  [20]: http://www.diaryofaninja.com/blog/2010/12/09/checking-for-network-connectivity-in-windows-phone-7-sdk
  [21]: http://const.me/articles/win-phone-7/
  [22]: http://www.scottlogic.com/blog/2011/12/15/a-simple-multi-page-windows-phone-7-phonegap-example.html
  [23]: http://www.charlespetzold.com/phone/index.html
  [24]: http://www.amazon.com/Professional-Windows-Phone-Application-Development/dp/0470891661/ref=ntt_at_ep_dpi_4/179-5348678-9414068
  [25]: http://www.amazon.com/Pro-Windows-Phone-7-Development/dp/1430232196/ref=pd_sim_sbs_b_2
  [26]: http://www.amazon.com/Beginning-Windows-Phone-7-Development/dp/1430232161/ref=pd_sim_sbs_b_3
  [27]: http://www.amazon.com/Learning-Windows-Programming-Yochay-Kiriaty/dp/1449388361/ref=pd_sim_sbs_b_4
  [28]: http://www.amazon.com/Windows-Phone-7-Game-Development/dp/1430233060/ref=pd_sim_sbs_b_6
  [29]: http://www.amazon.com/Windows-Application-Development-Developers-Library/dp/0672332221/ref=pd_sim_sbs_b_9
  [30]: http://www.amazon.com/101-Windows-Phone-Apps-Developing/dp/0672335522/ref=sr_1_1?ie=UTF8&amp;qid=1308054520&amp;sr=1-1-spell
  [31]: http://www.amazon.com/101-Windows-Phone-Apps-Developing/dp/0672335603/ref=pd_sim_b_1
  [32]: http://www.dotnetrocks.com/default.aspx?showNum=539
  [33]: http://www.dotnetrocks.com/default.aspx?showNum=542
  [34]: http://www.hanselminutes.com/default.aspx?showID=224
  [35]: http://www.hanselminutes.com/default.aspx?showID=225
  [36]: http://channel9.msdn.com/Blogs/egibson/Windows-Phone-7-Jump-Start-Session-1-of-12-Introduction
  [37]: http://www.dnrtv.com/default.aspx?showNum=172
  [38]: http://channel9.msdn.com/tags/WP7/
  [39]: http://www.diaryofaninja.com/blog/2012/01/23/8-musthave-tools-for-windows-phone-7-development
  [40]: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=04704acf-a63a-4f97-952c-8b51b34b00ce&amp;displaylang=en
  [41]: http://eqatec.com/Profiler
  [42]: http://www.bugsense.com/docs/windowsphone
  [43]: http://ioc.codeplex.com/
  [44]: http://nuget.org/List/Packages/Autofac.Wp7
  [45]: http://msaf.codeplex.com
  [46]: http://www.galasoft.ch/mvvm/getstarted/
  [47]: http://columbus.codeplex.com
  [48]: http://windowsphonemvp.codeplex.com/
  [49]: http://caliburnmicro.codeplex.com/

Getting Started with Windows Phone 7

I have a DataGrid which is populating data from ViewModel by asynchronous method.My DataGrid is :
   

    &lt;DataGrid ItemsSource=&quot;{Binding MatchObsCollection}&quot;  x:Name=&quot;dataGridParent&quot; 
                          Style=&quot;{StaticResource EfesDataGridStyle}&quot; 
                          HorizontalGridLinesBrush=&quot;#DADADA&quot; VerticalGridLinesBrush=&quot;#DADADA&quot; Cursor=&quot;Hand&quot; AutoGenerateColumns=&quot;False&quot; 
                          RowDetailsVisibilityMode=&quot;Visible&quot;  &gt;

I am using http://www.amazedsaint.com/2010/10/asynchronous-delegate-command-for-your.html to implement asynchronous way in my viewmodel.

Here is my viewmodel code:

    public class MainWindowViewModel:WorkspaceViewModel,INotifyCollectionChanged
        {        
            
            MatchBLL matchBLL = new MatchBLL();
            EfesBetServiceReference.EfesBetClient proxy = new EfesBetClient();
            
            public ICommand DoSomethingCommand { get; set; }
            public MainWindowViewModel()
            {
                DoSomethingCommand = new AsyncDelegateCommand(
                    () =&gt; Load(), null, null,
                    (ex) =&gt; Debug.WriteLine(ex.Message));           
                _matchObsCollection = new ObservableCollection&lt;EfesBet.DataContract.GetMatchDetailsDC&gt;();                
                
            }       
            
            List&lt;EfesBet.DataContract.GetMatchDetailsDC&gt; matchList;
            ObservableCollection&lt;EfesBet.DataContract.GetMatchDetailsDC&gt; _matchObsCollection;
    
            public ObservableCollection&lt;EfesBet.DataContract.GetMatchDetailsDC&gt; MatchObsCollection
            {
                get { return _matchObsCollection; }
                set
                {
                    _matchObsCollection = value;
                    OnPropertyChanged(&quot;MatchObsCollection&quot;);
                }
            }        
            //
            public void Load()
            {            
                matchList = new List&lt;GetMatchDetailsDC&gt;();
                matchList = proxy.GetMatch().ToList();
    
                foreach (EfesBet.DataContract.GetMatchDetailsDC match in matchList)
                {
                    _matchObsCollection.Add(match);
                }
                
            }

As you can see in my Load() method in my ViewModel first I am getting matchList (which is a list of a DataContract Class) from my Service.Then by foreach loop I am inserting my matchList items to my _matchObsCollection(which is an ObservableCollection of DataContract Class)).Now here I am getting the above error (as I shown in Title) &quot;This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread&quot; 
![enter image description here][1]


  [1]: http://i.stack.imgur.com/zHgtd.jpg

Can anyone suggest me any solution.Moreover if possible I would like to know how to bind my DataGrid in View and also refresh it asynchronously if any better way is there.

This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread

In my silverlight application I am trying to create a database connection using LINQ.
First I add a new LINQ to SQL class, and drag my table called &quot;tblPersoon&quot; into it.

Then in my service file I try to execute the following query:

    [OperationContract]
    public tblPersoon GetPersoonByID(string id)
    {
        var query = (from p in tblPersoon where p.id == id select p).Single();

But at tblPersoon it gives me the following error.

&gt; Could not find an implementation of the query pattern for source type
&gt; &#39;SilverlightApplication1.Web.tblPersoon&#39;.  &#39;Where&#39; not found.

And even when I try the following:

    var query = (from p in tblPersoon select p).Single();

It gives me an error saying &#39;Select&#39; not found!

Code for the generated class for my table can be found here: http://pastebin.com/edx3XRhi

What is causing this and how would I possibly solve this?

Thank you.



Could not find an implementation of the query pattern

&gt; **Possible Duplicate:**  
&gt; [What is the difference between WPF and Silverlight application?](https://stackoverflow.com/questions/629927/what-is-the-difference-between-wpf-and-silverlight-application)  

&lt;!-- End of automatically inserted text --&gt;

What are the exact differences between WPF and Silverlight? 

WPF vs Silverlight

I&#39;m currently creating an application in C# using Visual Studio. I want to create some code so that when a variable has a value of 1 then a certain piece of code is carried out.
I know that I can use an if statement but the problem is that the value will be changed in an asynchronous process so technically the if statement could be ignored before the value has changed.

Is it possible to create an event handler so that when the variable value changes an event is triggered? If so, how can I do this?

It is completely possible that I could have misunderstood how an if statement works! Any help would be much appreciated.

How to trigger event when a variable&#39;s value is changed?

I have a very simple test app just to play around with Windows Phone 7. I&#39;ve just added a `TextBox` and a `TextBlock` to the standard UI template. The only custom code is the following:

    public partial class MainPage : PhoneApplicationPage
    {
        public MainPage()
        {
            InitializeComponent();
        }

        private int counter = 0;

        private void TextBoxChanged(object sender, TextChangedEventArgs e)
        {
            textBlock1.Text += &quot;Text changed &quot; + (counter++) + &quot;\r\n&quot;;
        }
    }

The `TextBox.TextChanged` event is wired up to `TextBoxChanged` in the XAML:

    &lt;TextBox Height=&quot;72&quot; HorizontalAlignment=&quot;Left&quot; Margin=&quot;6,37,0,0&quot;
             Name=&quot;textBox1&quot; Text=&quot;&quot; VerticalAlignment=&quot;Top&quot;
             Width=&quot;460&quot; TextChanged=&quot;TextBoxChanged&quot; /&gt;

However, every time I press a key when running in the emulator (either the on-screen keyboard or the physical one, having pressed Pause to enable the latter) it increments the counter twice, displaying two lines in the `TextBlock`. Everything I&#39;ve tried shows that the event is genuinely firing twice, and I&#39;ve no idea why. I&#39;ve verified that it&#39;s only being subscribed once - if I unsubscribe in the `MainPage` constructor, nothing happens at all (to the text block) when the text changes.

I&#39;ve tried the equivalent code in a regular Silverlight app, and it didn&#39;t occur there. I don&#39;t have a physical phone to reproduce this with at the moment. I haven&#39;t found any record of this being a known problem in the Windows Phone 7.

Can anyone explain what I&#39;m doing wrong, or should I report this as a bug?

EDIT: To reduce the possibility of this being down to having two text controls, I&#39;ve tried removing the `TextBlock` completely, and changing the TextBoxChanged method to *just* increment `counter`. I&#39;ve then run in the emulator, typed 10 letters and *then* put a breakpoint on the `counter++;` line (just to get rid of any possibility that breaking into the debugger is causing issues) - and it shows `counter` as 20.

EDIT: I&#39;ve now [asked in the Windows Phone 7 forum][1]... we&#39;ll see what happens.


  [1]: http://social.msdn.microsoft.com/Forums/en-US/windowsphone7series/thread/cb9b5544-a75e-4c9c-8475-0bf29e0bb5e3

TextBox.TextChanged event firing twice on Windows Phone 7 emulator

I&#39;ve installed Visual Studio 2010 (fresh install), then applied the SP1. Now I&#39;ve tried to install the silverlight 4 tools, but i&#39;m getting a strange error message : 

&quot;Visual Studio 2010 or Visual Web Developer Express 2010 or Visual Phone Developer Express 2010 that matches the language version of Silverlight Tools 4 must be installed before installation of Silverlight Tools can continue.  Silverlight Tools is available in other languages at &lt;A HREF=&quot;http://go.microsoft.com/fwlink/?LinkId=177432&quot;&gt;http://go.microsoft.com/fwlink/?LinkId=177432&lt;/A&gt;. 

The Visual Web Developer feature for Visual Studio 2010 must be installed before installation can continue.&quot;

I&#39;ve triple checked and there&#39;s no language conflict. Browsing the web, some guys have the same error, but there are some MSDN posts that say that with SP1 you don&#39;t need to install silverlight tools because they&#39;re already bundled with SP1, but that&#39;s not the case here, I don&#39;t have any project templates in VS for silverlight, and the tools aren&#39;t installed. Any ideas??

Cannot install silverlight 4 tools on visual studio 2010 sp1

How to create a style based on default style in Silverlight?

For example, in WPF we make it like:

    &lt;Style TargetType=&quot;{x:Type TextBox}&quot; BasedOn=&quot;{StaticResource {x:Type TextBox}}&quot;&gt;
      &lt;Setter Property=&quot;Margin&quot; Value=&quot;2&quot; /&gt;
      &lt;Setter Property=&quot;Padding&quot; Value=&quot;2&quot; /&gt;
    &lt;/Style&gt;


How to create a style based on default style?

I want to take a collection of objects and bind it to a StackPanel so basically if the collection has 4 elements, inside the stack panel that should produce 4 buttons lets say.

I tried this...But I dont think its the correct approach anyway. I used DataTemplated to do this type of idea in the past.. please correct me if I am wrong.

**Here is my fake model**

    public class MockModel
    {
       public ObservableCollection&lt;MockNode&gt; Nodes;
    
       public MockModel()
       {
          Nodes = new ObservableCollection&lt;MockNode&gt;();
       }
    }
    
    public class MockNode
    {
       public MockNode()
       {
       }
       
       private string itemname;
       public string ItemName
       {
          get { return this.itemname; }
          set { this.itemname = value; }
       }
    }

**In code I set the DataContext like this...**

    // Init Model
    MockModel myModel = new MockModel();
    
    for (int i = 0; i &lt; 4; i++)
    {
       MockNode mn = new MockNode();
       mn.ItemName = String.Format(&quot;Node {0}&quot;, i);
       myModel.Nodes.Add(mn);
    }
    // Set DataContext for StackPanel
    Stack.DataContext = myModel.Nodes;



**And the xaml**

    &lt;StackPanel x:Name=&quot;tStack&quot;&gt;
       &lt;ItemsControl ItemsSource=&quot;{Binding Nodes}&quot;&gt;
          &lt;ItemsControl.Template&gt;
             &lt;ControlTemplate&gt;
                &lt;Button Content=&quot;{Binding ItemName}&quot;/&gt;
             &lt;/ControlTemplate&gt;
          &lt;/ItemsControl.Template&gt;
       &lt;/ItemsControl&gt;
    &lt;/StackPanel&gt;

IT does bind but instead of 4 buttons I only get one button....

Ideas?


Bind Collection to StackPanel

I have a Silverlight 4 application. I have a C# DateTime object that I&#39;m binding to my UI. I want this DateTime to be in the format of `dd/mm/yyyy` time (TimeZone). For instance, today would be displayed as

    04/07/2011 at 01:13 p.m. (EST)

Is there a way to do this `XAML`? Or do I need to build a converter?

Format Date/Time in XAML in Silverlight

I have the feeling that [Flash][1]-based ( or [Silverlight][2]-based) websites are generally frowned upon, except when you are creating games or multimedia-content rich applications. Why this is so?

  [1]: http://en.wikipedia.org/wiki/Adobe_Flash
  [2]: http://en.wikipedia.org/wiki/Microsoft_Silverlight


What is so evil about a Flash based website?

My company develops several types of applications.  A lot of our business comes from doing multimedia-type apps, typically done in Flash.  However, now that side of the house is starting to migrate towards doing Flex development.

Most of our other development is done using .NET.  I&#39;m trying to make a push towards doing Silverlight development instead, since it would take better advantage of the .NET developers on staff.  I prefer the Silverlight platform over the Flex platform for the simple fact that Silverlight is all .NET code.  We have more .NET developers on staff than Flash/Flex developers, and most of our Flash/Flex developers are graphic artists (not real programmers).  Only reason they push towards Flex right now is because it seems like the logical step from Flash.

I&#39;ve done development using both, and I honestly believe Silverlight is easier to work with.  But I&#39;m trying to convince people who are only Flash developers. 

So here&#39;s my question:  If I&#39;m going to go into a meeting to praise Silverlight, why would a company want to go with Silverlight instead of Flex?  Other than the obvious &quot;not everyone has Silverlight&quot;, what are the pros and cons for each?

Silverlight vs Flex

By default, the `Validation.ErrorTemplate` in **WPF** is just a small red border without any `ToolTip`.

In **Silverlight 4**, the validation error is nicely styled out-of-the-box.  

Here is a comparison of a validation error occuring in Silverlight 4 and WPF

**Silverlight 4**  
![enter image description here][1]  
**WPF**  
![enter image description here][2]

Notice the really flat, boring look of the WPF version compared to the, in my opinion, great look in Silverlight.

Does any similar validation styles/templates exist in the WPF Framework or has anybody created nicely styled validation templates like the **Silverlight** version above? Or will I have to create them from scratch?

If anybody wants to try it out, the validation error above can be reproduced with the following code, works for both **Silverlight** and **WPF**

*MainWindow/MainPage.xaml*

    &lt;StackPanel Orientation=&quot;Horizontal&quot; Margin=&quot;10&quot; VerticalAlignment=&quot;Top&quot;&gt;
        &lt;TextBox Text=&quot;{Binding Path=TextProperty, Mode=TwoWay, ValidatesOnExceptions=True}&quot;/&gt;
        &lt;Button Content=&quot;Tab To Me...&quot; Margin=&quot;20,0,0,0&quot;/&gt;
    &lt;/StackPanel&gt;

*MainWindow/MainPage.xaml.cs*

    public MainWindow/MainPage()
    {
        InitializeComponent();
        this.DataContext = this;
    }

    private string _textProperty;
    public string TextProperty
    {
        get { return _textProperty; }
        set
        {
            if (value.Length &gt; 5)
            {
                throw new Exception(&quot;Too many characters&quot;);
            }
            _textProperty = value;
        }
    }


  [1]: http://i.stack.imgur.com/7hSRg.png
  [2]: http://i.stack.imgur.com/ESu4Q.png

Validation Error Style in WPF, similar to Silverlight

What is the difference for 

    TargetType=&quot;{x:Type Button}&quot;

and

    TargetType=&quot;Button&quot;

What is the difference for TargetType=&quot;{x:Type Button}&quot; and TargetType=&quot;Button&quot;?

I have a Silverlight application that is building a URL. This URL is a call to a REST-based service. This service expects a single parameter that represents a location. The location is in the form of &quot;city, state&quot;. To build this URL, I&#39;m calling the following code:

    string url = &quot;http://www.example.com/myService.svc/&quot;;
    url += HttpUtility.UrlEncode(locationTextBox.Text);

If a user enters &quot;chicago, il&quot; into locationTextBox, the result looks like this:

&lt;!-- language: lang-none --&gt;

    http://www.example.com/myService.svc/chicago%2c+il

In reality though, I was kind of expecting the URL to look like;

&lt;!-- language: lang-none --&gt;

    http://www.example.com/myService.svc/chicago,%20il

When testing my service via the browser URL, the one I am expecting works. However, the URL that is being generated is not working. What am I doing wrong?





Encoding parameters for a URL

What is meant by easing function in the context of animation. It seems that dojo, jquery, silverlight, flex and other UI systems have the notion of easing function. I could not locate a good explanation of easing functions? Can anyone explain the concept of easing functions, or point a good explanation of them, I am interested in the concept not in the specific details of a framework? 

Is easing strictly used for location or is it general and can be applied to any property of an object?  

What is an easing function?

  I have installed VS 2010 professional with full installation in Windows 7.

I have installed Silverlight 5.0 separately.

When I create  silverlight application, it asks for installing silverlight Developer runtime.
&gt; You need to install the latest Silverlight Developer runtime before creating a Silverlight project



 After downloading the runtime when I tried to install  it prompted that 

&gt; newer version of Silverlight is already installed

So I cant install runtime and I cant create siverlight application.

   
 
I tried to install Silverlight 5 tools, but it ask to install service pack 1 for visual studio.
 Microsoft Silverlight 3 SDK and Microsoft Silverlight 4 SDK are already installed in the system. Why SDK does not include the developer runtime ?

What are the things do we need to develop a silverlight application ?


Can&#39;t install Silverlight Developer runtime

I have `ObservableCollection&lt;T&gt;` collection, and I want to replace all elements with a new collection of elements, I could do:

    collection.Clear(); 

OR: 

    collection.ClearItems();

(BTW, what&#39;s the difference between these two methods?)

I could also use `foreach` to `collection.Add` one by one, but this will fire multiple times

Same when adding a collection of elements.

EDIT:

I found a good library here: [Enhanced ObservableCollection with ability to delay or disable notifications](http://www.codeproject.com/Articles/249311/Enhanced-ObservableCollection) but it seems that it does NOT support silverlight.

How to Avoid Firing ObservableCollection.CollectionChanged Multiple Times When Replacing All Elements Or Adding a Collection of Elements

In my Silverlight project, I would like to make an assembly which contains .xaml that can&#39;t be seen from outside of the assembly. However, there is no clear way I can do this. When I modify the access modifier on the .xaml.cs file, the compiler tells me:

    Partial declarations of &quot;My xaml class here&quot; have conflicting accessibility modifiers	

In the xaml file itself, there doesn&#39;t seem to be a place to put my access modifier. In short, how do I set the class associated with my xaml file to `internal`?

Make a XAML file internal in .NET

How can I access the public variable which in *Sample.xaml.cs* file like asp.net `&lt;%=VariableName%&gt;`?

Access codebehind variable in XAML

I want to have a Button that defines no `CornerRadius` and two others that do, how can I achieve this?

    &lt;Style TargetType=&quot;Button&quot; x:Key=&quot;TabButton&quot;&gt;
        &lt;Setter Property=&quot;Background&quot; Value=&quot;White&quot; /&gt;
        &lt;Setter Property=&quot;TextBlock.TextAlignment&quot; Value=&quot;Center&quot; /&gt;
        &lt;Setter Property=&quot;Template&quot;&gt;
            &lt;Setter.Value&gt;
                &lt;ControlTemplate TargetType=&quot;Button&quot;&gt;
                    &lt;Border CornerRadius=&quot;0&quot; Background=&quot;White&quot; BorderBrush=&quot;#ccc&quot; BorderThickness=&quot;0,1,1,0&quot; &gt;
                        &lt;ContentPresenter x:Name=&quot;contentPresenter&quot; ContentTemplate=&quot;{TemplateBinding ContentTemplate}&quot; Content=&quot;{TemplateBinding Content}&quot; HorizontalAlignment=&quot;{TemplateBinding HorizontalContentAlignment}&quot; Margin=&quot;{TemplateBinding Padding}&quot; VerticalAlignment=&quot;{TemplateBinding VerticalContentAlignment}&quot;/&gt;
                    &lt;/Border&gt;
                &lt;/ControlTemplate&gt;
            &lt;/Setter.Value&gt;
        &lt;/Setter&gt;
    &lt;/Style&gt;

    &lt;Style TargetType=&quot;Button&quot; x:Key=&quot;TabButtonFirst&quot; BasedOn=&quot;{StaticResource TabButton}&quot;&gt;
        &lt;Setter Property=&quot;CornerRadius&quot; Value=&quot;3,0,0,0&quot; /&gt;
    &lt;/Style&gt;

    &lt;Style TargetType=&quot;Button&quot; x:Key=&quot;TabButtonLast&quot; BasedOn=&quot;{StaticResource TabButton}&quot;&gt;
        &lt;Setter Property=&quot;CornerRadius&quot; Value=&quot;0,0,0,3&quot; /&gt;
    &lt;/Style&gt;

Set CornerRadius on button template

When working with Silverlight, I&#39;ve noticed that Firefox will cache the XAP file, so if I do an update, a user may be stuck using an outdated version.  Is there a way to force the browser to either re-download the XAP file every time, or maybe only force it to after an update has been published?  Or is there a setting in the Silverlight config that stops the browser from caching the XAP file altogether?

Thanks,
jeff

How do you force Firefox to not cache or re-download a Silverlight XAP file?

I&#39;ve been upgrading some Silverlight 3 apps to Silverlight 4 in Visual Studio 2010. My Silverlight 3 apps open fine in Visual Studio, but SL4 apps don&#39;t, with the following error:

`C:\Path\To\MyProject.csproj : error  : Unable to read the project file &#39;XNTVOD.AdminClient.csproj&#39;. 
C:\Path\To\MyProject.csproj(593,3): The imported project &quot;C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v4.0\Microsoft.Silverlight.CSharp.targets&quot; was not found. Confirm that the path in the &lt;Import&gt; declaration is correct, and that the file exists on disk.
`

I had a problem with older VS Silverlight components and recently uninstalled most of the SL components, and right now in Add/Remove programs I have:

 1. Microsoft Silverlight
 2. Microsoft Silverlight 3 SDK
 3. Microsoft Silverlight 4 Toolkit April 2010

The `&lt;import&gt;` declaration looks like this for the SL4 project:

`&lt;Import Project=&quot;$(MSBuildExtensionsPath32)\Microsoft\Silverlight\$(SilverlightVersion)\Microsoft.Silverlight.CSharp.targets&quot; /&gt;`

That folder, `C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v4.0` only has two files in it:

`Microsoft.Ria.Client.targets`

`Microsoft.Ria.Client.VisualStudio.targets`

What Silverlight development component am I missing in particular? I see a bunch of different options, from Silverlight 4 SDK Beta to VS Tools for Silverlight 4 and a bunch of others. I don&#39;t want to install stuff that will get me right back to the situation I had before this one with outdated components.

Silverlight 4: Resolving Microsoft.Silverlight.CSharp.targets was not found?

The look of a WPF CheckBox misaligns the check portion with the label (content) portion. The check stays slightly above the content as shown here:

![enter image description here][1]

The XAML looks like this:

    &lt;CheckBox Content=&quot;Poorly aligned CheckBox&quot; Margin=&quot;9&quot;/&gt;

The CheckBox is inside a Grid cell. **Is there a simple way to make the content and check portions of a XAML CheckBox align vertically?** I&#39;ve tried various combinations of properties with no luck. I saw [a similar question here][2] but the answer is way too complex.

Thanks in advance.

**EDIT: The problem was caused by the Window FontSize which I set to 14**. To re-create the problem set the CheckBox FontSize to 14 (or more). My program is viewed at a distance by factory workers so I allow the Window FontSize to be increased or decreased by the user.


  [1]: http://i.stack.imgur.com/cTT3O.png
  [2]: https://stackoverflow.com/questions/6077510/how-can-i-center-a-wpf-checkbox-inside-its-clickable-region

All Silverlight Solutions on Gang of Coders

Total of 28 Silverlight Solutions