Thanks in advance for any help with this. It is driving me nuts. Here is the setup:
I have a Silverlight Control Library "Controls", in which I have a customer control defined for presenting dialogs:
public class Dialog : ContentControl
{
public Dialog()
: base()
{
DefaultStyleKey = typeof(Dialog);
}
<...normal custom control stuff...>
}
also the default style is in generic.xaml:
<Style TargetType="src_general:Dialog">
<Setter Property="Padding" Value="25"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="src_general:Dialog">
<Grid x:Name="RootElement" >
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="DiakogStyleStates">
<vsm:VisualState x:Name="OkCancel">
<Storyboard>
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="OkOnly">
<Storyboard>
<ObjectAnimationUsingKeyFrames Duration="0:0:0" Storyboard.TargetName="CancelButton" Storyboard.TargetProperty="Visibility" >
<DiscreteObjectKeyFrame KeyTime="0:0:0" >
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="CancelOnly">
<Storyboard>
<ObjectAnimationUsingKeyFrames Duration="0:0:0" Storyboard.TargetName="OkButton" Storyboard.TargetProperty="Visibility" >
<DiscreteObjectKeyFrame KeyTime="0:0:0" >
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="None">
<Storyboard>
<ObjectAnimationUsingKeyFrames Duration="0:0:0" Storyboard.TargetName="CancelButton" Storyboard.TargetProperty="Visibility" >
<DiscreteObjectKeyFrame KeyTime="0:0:0" >
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Duration="0:0:0" Storyboard.TargetName="OkButton" Storyboard.TargetProperty="Visibility" >
<DiscreteObjectKeyFrame KeyTime="0:0:0" >
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<Popup x:Name="DialogPopup">
<src_general:WindowFrame x:Name="Frame">
<Grid >
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ContentPresenter Grid.Row="0" x:Name="ContentPresenter" Margin="{TemplateBinding Padding}"/>
<!--Action Buttons-->
<StackPanel Grid.Row="1" Orientation="Horizontal" HorizontalAlignment="Right" Margin="15">
<src_general:GlassButton x:Name="CancelButton" Content="Cancel" Margin="2"/>
<src_general:GlassButton x:Name="OkButton" Content="Ok" Margin="2"/>
</StackPanel>
</Grid>
</src_general:WindowFrame>
</Popup>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
I use this dialog in a lot of places with no problem. However, in one application, nested about 3-4 usercontrols from the RootVisual, I use it the following way:
<general:Dialog x:Name="AddUpdateDialog" DialogStyle="OkCancel" Title="Add/Update Connection" Closed="AddUpdateDialog_Closed" ValidationGroup="AddConnection">
<Grid Width="300">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="10"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Text="Name:" Style="{StaticResource LabelText}"/>
<TextBox Grid.Row="0" Grid.Column="2" Text="{Binding Name, Mode=TwoWay}" Style="{StaticResource TextBoxInput}" MaxLength="49">
<val:ValidationManager.Validator>
<val:RequiredValidator ManagerName="AddConnection" ErrorMessage="Name is required."/>
</val:ValidationManager.Validator>
</TextBox>
</Grid>
</general:Dialog>
When I run this app I intermittently (about every 5-10 starts get the following exception:
"Unable to cast object of type 'System.Windows.Controls.ContentControl' to type 'hookitupright.com.silverlight.controls.general.Dialog'." that occurs in the InitializeComponent() for the parent UserControl of the above XAML. To be sepcific, it occurs right here:
this.AddUpdateDialog = ((hookitupright.com.silverlight.controls.general.Dialog)(this.FindName("AddUpdateDialog")));
When I put a breakpoint there, most of the time the FindName returns a Dialog typed object, but sometimes, it returns a ContentControl (the base for Dialog) and it fails. The XAML has not changed. It is static...Since the exception is intermittent and occurs within generated code I am at a loss.
I have tried:
1) Moved all of the content for the Dialog into a separate UserControl - only seemed to make problem worse
2) Comment out parts and see when it works...well, if I comment out the TextBox completely, it no longer fails. Everything else (including the custom validation attached property) seems to have no impact.
2a) Thinking it may have something to do with the TwoWay binding to the TextBox, I removed the binding. Still fail.
UPDATE: So given 2) above I left the Textbox commented out decided to move on to other things and come back to this with hopes that something will reveal itself to me. Unfortunately, it seems to also fail with the textbox out, just less frequently.
In addition, I have this control in the exact same configuration in another usercontrol in the same app (and at the same level in the VisualTree) and it does not fail at all. So I literally copied and pasted the failing XAML into the Main.xaml (my root visual) and of course, it does not fail there either. Assuming that the the XAML is loaded in sequence (top to bottom) the failing control is likely one of the last ones loaded. My only hypothesis now is that there is some timing thing that is happening whereby as Iam still loading the visual tree, I start to get *Completed events from the loading of the data via WCF service and that these trigger a layout before the visual tree is fully loaded which causes some ill side effects... I will test this.
The problem is that it does NOT fail every time. It blows up about 20% of the time. When it works, everything works even this dialog???
This problem is related if not the same problem: When I "fix" the invalidcast by commenting out needed functionality, I will far less frequently but intermittently get this invalid attribute (when the attribute/property is in fact there).
http://stackoverflow.com/questions/229117/xamlparseexception-attribute-in-custom-control-missing-but-its-defined#473015
Help please.
From stackoverflow
