SL beta2 Known Issue

Silverlight 2 (beta1) Known Issues and workarounds (if any)

1 Apr,2008  Silverlight

The following is the List of kNown issues for Silverlight 2 beta 1.

But this is not something new. If you keep on reading Silverlight Forum,you may already aware of those issues. but I wrote this post for those who are not aware of those issues. If you are facing some strange issues,please come and check before spending too much time for finding why something is not working as expected. I hope that you will find it useful. The most of issues are confirmed by Yi-Lun (MSFS) in our forum. (Thanks! Yi-Lun)

If you want to share some SL2 kNown issues that you like to share with everybody,please let me kNow.

List of issues

Issue #1: Binding DatagrID with Anonymous type will crash the browser. Source: http://silverlight.net/forums/p/11147/36232.aspxProblem ~Binding DatagrID with Anonymous type will crash the browser

Steps to reproduce ~

view plaincopy to clipboardprint?

<my:DataGrID x:name="myDataGrID" Height="200" WIDth="700" margin="0,10"

autoGenerateColumns="True" VerticalAlignment="top">

string str = string.Empty;str = @"<?xml version=""1.0"" encoding=""utf-8"" ?>";  

string str = string.Empty;str = @"<?xml version=""1.0"" encoding=""utf-8"" ?>";

str = "<Products>";

str += "<Product>";

str += "<ID>";

str += "1";

str += "</ID>";

str += "<Name>";

str += "dd";

str += "</Name>";

str += "</Product>";

str += "<Product>";

str += "<ID>";

str += "2";

str += "</ID>";

str += "<Name>";

str += "ee";

str += "</Name>";

str += "</Product>";

str += "</Products>";XDocument xmlSource = XDocument.Parse(str);

var products = from p in xmlSource.Descendants("Product")

select new

{

ID = Convert.ToInt32(p.Element("ID").Value),

Name = (string)p.Element("Name").Value

};

myDataGrid.ItemsSource = products;

Workarounds ~Create the class explicitly

Yi-Lun from Microsoft explained about this issue as below.

Hello,actually the problem is: Anonymous Types are internal. Currently data binding doesn’t support binding to non-public classes. Try to use a ListBox to bind to an internal class,you’ll find a similar problem.

The root cause seems to be: Data binding uses reflection,and reflection needs high security permissions. Silverlight runs in a sand box,where such security permissions are not granted.

However,I found that it’s working fine with Listbox. So,we are still discussing about this issue. I will update this post once we got the final conclusion.

Credit: Thanks to Yi-lun for verifying this issue.

Issue #2: Binding Datagrid with Anonymous type will crash the browser.Source : http://silverlight.net/forums/t/13077.aspxThere are two sub-issues in this issue.

Create new Silverlight 2 project

<TextBox x:Name="Txt"  TextChanged="Txt_TextChanged" />  

<TextBox x:Name="Txt"  TextChanged="Txt_TextChanged" />

WordaroundsNone:

Credit: Thanks to pavelsua for reporting this issue. He reported the issue 2.1. When I tried to verify his issue,I found another one (2.2). Issue #3. Controls inside the canvas don’t appear until mouse hovers over them.

Source : http://silverlight.net/forums/t/10906.aspxSymptom: A canvas has visibility changed from Visibilty.Collapsed to Visibilty.Visible but controls insIDe the canvas don’t appear until mouse hovers over them.

Steps to reproduce:

1. Create a Silverlight 2 app
2. Change the Page XAML to look like this (either manually or in Blend)

<UserControl x:Class="SilverlightApplication3.Page"  

<UserControl x:Class="SilverlightApplication3.Page"

xmlns="http://schemas.microsoft.com/client/2007"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Width="400" Height="300">

<Canvas x:Name="LayoutRoot" Background="White">

<Button Height="20" Width="120" Canvas.Left="0" Canvas.Top="0" Content="Button" x:Name="btnTest"/>

<Canvas Height="68" Width="120" Canvas.Top="0" Visibility="Collapsed" x:Name="cnvTest">

<Button Height="20" Width="50" Content="Button" Canvas.Top="48"/>

</Canvas>

</Canvas>

</UserControl>

3. Change the Visibility of cnvTest on clicking the button

public Page(){  

public Page(){

InitializeComponent();

btnTest.Click += new RoutedEventHandler(btnTest_Click);

}

void btnTest_Click(object sender,RoutedEventArgs e){

cnvTest.Visibility = Visibility.Visible;

}

Expected: the button in the canvas to be shown as soon as the canvas is made visible.

Workarounds ~

Credits: Thanks to AdamJTP for reporting this issue and sharing the workaround.————-

Issue #4. Cursor will disappear when you add the textbox after removingSource : http://silverlight.net/forums/p/11142/36252.aspx: The cursor of textBox won’t show when adding the textBox that is removed earlIEr at runtime.

~

1. The code is written in Page.xaml. There are one button for adding new textBox,another button for removing the textBox and one canvas where the textBox suppose to be added or removed.

<UserControl x:Class="SL2KnownIssue.Page"  

<UserControl x:Class="SL2KnownIssue.Page"

xmlns="http://schemas.microsoft.com/client/2007"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Width="400" Height="300">

<Grid x:Name="LayoutRoot" Background="White">

<StackPanel>

<Button x:Name="add" Content="Add"></Button>

<Button x:Name="remove" Content="Remove"></Button>

<Canvas x:Name="placeHolder" Background="Red" Width="100"   Height="100">

</Canvas>

</StackPanel>

</Grid>

</UserControl>

2. The code is written in Page.xaml.cs

namespace SL2KnownIssue {  

namespace SL2KnownIssue {

public partial class Page : UserControl {

TextBox txt = new TextBox();

public Page() {

InitializeComponent();

add.Click += new RoutedEventHandler(add_Click);

remove.Click += new RoutedEventHandler(remove_Click);

}

void remove_Click(object sender,RoutedEventArgs e) {

placeHolder.Children.Remove(txt);

}

void add_Click(object sender,RoutedEventArgs e) {

placeHolder.Children.Add(txt);

}

}

}

3. Run the application

4. Click “Add” button to add the textbox to the screen on the fly.

5. Try to type something in that textbox that you added. (Observe: It will be working fine as you expected.)

6. Click “Remove” button to remove the textbox and click “Add” button again.

7. then,type something in this textbox. (Observe: At this time,you are still able to type it but you won’t see the cursor anymore. )

Initially,I was thinking that the workaround would be “hiding/showing” instead of “removing and adding”. But it won’t work since we already have issue #1. So,I think there is no workaround for that. Be careful when you are trying to remove or add the element.

Credits: Thanks to sgzwkrm for reporting this issue and Yi-Lun for confirming this issue. Issue #5. DispatcherTimer doesn’t allow event subscription after timer is startedSource: http://silverlight.net/forums/p/12652/41581.aspx: dispatcherTimer doesn’t allow any event subscription after timer is started

Steps to reproduce

1. Attach the Tick event to Timer after calling Start() method

_timer = new DispatcherTimer();  

_timer = new DispatcherTimer();

_timer.Interval = TimeSpan.FromSeconds(0.5);

_timer.Start();

_timer.Tick += new EventHandler(_timer_Tick);

Obseve: _timer_Tick will never be called.

Workaround ~Obviously,you have to attach the event before calling Start() method.

Credits: Thanks to Florian Kruesch for reporting this issue and Allen Chen for confirming this issue. Issue #6. The exception occurs if you hIDe the button in Click event Source: http://silverlight.net/forums/p/12519/41100.aspxDescription:

Steps to reproduce ~

1. Add one button in XAML

</UserControl>  

<UserControl x:Class="SL2KnownIssue.Page"

xmlns="http://schemas.microsoft.com/client/2007"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Width="400" Height="300">

<Grid x:Name="LayoutRoot" Background="White">

<Button x:Name="add" Content="Add"></Button>

</Grid>

</UserControl>

<usercontrol x:></usercontrol>

2. Attach the Click event in that button and hide it in that event

add.Visibility = Visibility.Collapsed;  

public Page() {

InitializeComponent();

add.Click += new RoutedEventHandler(add_Click);

remove.Click += new RoutedEventHandler(remove_Click);

}

void add_Click(object sender,RoutedEventArgs e) {

add.Visibility = Visibility.Collapsed;

}

}

3. Run the application and click the button. (Ob: You will get the following error.)

Error Message:“Error HRESULT E_FAIL has been returned from a call to a COM component”

stack trace :
at MS.Internal.XcpImports.MethodEx(IntPtr ptr,String name,CValue[] cvData)
at System.Windows.DependencyObject.MethodEx(String methodName,CValue[] cvData)
at System.Windows.UIElement.ReleaseMouseCapture()
at System.Windows.Controls.Primitives.ButtonBase.ReleaseMouseCaptureInternal()
at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(Object sender,MouseButtonEventArgs e)
at System.Windows.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex,Delegate handlerDelegate,Object sender,Object args)
at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj,IntPtr unmanagedObjArgs,Int32 argsTypeIndex,String eventName)

Disable the button instead of hiding. OR

Yi-Lun from Silverlight explained about this issue as below ~

Credits: Thanks to hotdave2 for reporting this issue and Thanks to Yi-Lun for providing good explanation and workarounds for this issue.Issue #7. Textbox doesn’t work well with non-English keyboardSource : http://silverlight.net/forums/t/10705.aspxSome reported that they are not able to type accented characters,like ‘é’,Alt Gr and Ctrl+’,<letter> in textBox if they are using non-English keyboard such as Spanish,German and etc.

None

Credit: Thanks to everyone who are participating in this post. Issue #8. Scrollbar HorizontalRootElement shows as artifact behind VerticalRootElement Source : http://silverlight.net/forums/p/12939/42610.aspx and http://silverlight.net/forums/p/10698/34561.aspxProblem : An artifact of the HorizontalRootElement (from the HorizontalThumbTemplate) is clearly visible.

Steps to reproduce ~

ElementVerticalTemplate = GetTemplateChild(ElementVerticalTemplateName) as FrameworkElement;  

ElementVerticalTemplate = GetTemplateChild(ElementVerticalTemplateName) as FrameworkElement;

Credits: Thanks to jseaver and Attila for reporting this issue and thanks to Attila and Yi-Lun for showing the workarounds.Issue #9. Border.Child - System.ArgumentException and System.AccessViolationExceptionSource: http://silverlight.net/forums/p/11401/36428.aspxUsing SL2B1 with C# (and ie7),the border control will throw an exception if the Child property is set to the same object twice.

Example:

UserControl A;
UserControl B;

myborder.Child = A; //OK
myborder.Child = B; //OK
myborder.Child = B; //Exception

An exception of type ‘System.ArgumentException’ occurred in System.windows.dll but was not handled in user code
Additional information: Value does not fall within the expected range.

Also along these lines,setting Child to null produces another exception,

myborder.Child = null;

An exception of type ‘System.AccessViolationException’ occurred in System.windows.dll but was not handled in user code
Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

Credit: Thanks to UncleRedz for reporting this issue and Pranav Goel for confirming this issue.Issue #10: HorizontalAlignment not respected in Silverlight as in WPF Source: http://silverlight.net/forums/p/12636/41513.aspxProblems ~

Note: The following is reported by MichaelGG from Silverlight forum.In WPF setting HorizontalAlignment on a control will let it resize itself if it’s insIDe a @R_372_4041@ element. For example:

<Window x:Class=”WpfApplication1.Window1″
xmlns=”http://schemas.microsoft.com/winfx/2006/xaml/presentation”
xmlns:x=”http://schemas.microsoft.com/winfx/2006/xaml”
Title=”Window1″ Height=”auto” WIDth=”auto”>
<GrID>
<StackPanel>
<button Content=”asd” HorizontalAlignment=”Center” />
</StackPanel>
</GrID>
</Window>

This will show a button not much larger than it’s content,centered in the Window. However,doing the same in Silverlight fails:

<UserControl x:Class=”SilverlightApplication1.Page”
xmlns=”http://schemas.microsoft.com/client/2007”
WIDth=”auto” Height=”auto”>
<GrID>
<StackPanel>
<button Content=”asd” HorizontalAlignment=”Center” />
</StackPanel>
</GrID>
</UserControl>

The button is @R_372_4041@ across the entire window.

My WPF-layout-powers are not that strong,so it’s quite possible that I’m missing something here. But it does appear as if SL isn’t behaving how it should.

WorkaroundNote: The following is replIEd from Yi-Lun.<Path x:Name="CurvedBevel" Stretch="Fill" Margin="3,3,0" Data="F1 M 0,0.02 V 0.15 C 0.15,0.22 0.30,0.25 0.50,0.26 C 0.70,0.26 0.85,0.22 1,0.15 V 0.02 L 0.97,0 H 0.02 L 0,0.02 Z">  

<Path x:Name="CurvedBevel" Stretch="Fill" Margin="3,0" Data="F1 M 0,0.02 V 0.15 C 0.15,0.22 0.30,0.25 0.50,0.26 C 0.70,0.26 0.85,0.22 1,0.15 V 0.02 L 0.97,0 H 0.02 L 0,0.02 Z">

Nice as it is,this will cause layout problems. Add this Path to a WPF’s Button’s template,and you’ll get the same result. So you have to override the Button’s template,and remove this Path or so…

Issue #11: TextBlock MouseEvent doesn’t work properly when text alignment is applied Source: http://silverlight.net/forums/t/12672.aspxAll Mouse event of TextBlock is not fired when TextAlignment =”Center” .

Steps to reproduces ~Put the following code in XAML (e.g. Page.xaml)

<TextBlock x:Name="textBlock"  

<TextBlock x:Name="textBlock"

Width="400"

VerticalAlignment="Center"

TextAlignment="Center"

Text="Center aligned text"

MouseMove="TextBlock_MouseMove"

MouseEnter="TextBlock_MouseEnter"

MouseLeave="TextBlock_MouseLeave"></TextBlock>

private void TextBlock_MouseMove(object sender, MouseEventArgs e)  

private void TextBlock_MouseMove(object sender,MouseEventArgs e)

{

this.textBlock.FontStyle = FontStyles.Italic;}private void TextBlock_MouseEnter(object sender,MouseEventArgs e)

{

this.textBlock.Foreground = highlight;

}private void TextBlock_MouseLeave(object sender,MouseEventArgs e)

{

this.textBlock.Foreground = normal;

this.textBlock.FontStyle = FontStyles.Normal;

}

Credit: Thanks to Jongho for reporting this issue.Issue #12: The storePath of Isolated Storage in Application_Startup event and the storepath in Application_Exit event are different.

Source: http://silverlight.net/forums/p/12247/42471.aspxThe storePath of Isolated Storage in Application_Startup event and the storepath in Application_Exit event are different.

Download the sample project from this link.(Thanks to Jong Ho for making this sample for me.)

A workaround is to cache the isolated storage path in the Startup event,or handle the HTML window.onunload event instead of Silverlight’s Exit event.

Credit: Thanks to bpatters for reporting this issue,Jong Ho for making the demo and Yi-lun for verifying this issue and provIDing the workaround.That’s all for Now. I have 3 or 5 issues in my List. I will update those issue tomorrow or this weekend. If you have any kNown issue of Silverlight 2 beta1,please let me kNow.