Catch Events from Within Templates

Mon, 13 Aug 2007 16:20:46 Z

Here the pretty much simplyfied code:

Code Snippet

<Page.Resources>

<Border.Triggers>

</EventTrigger>

<Border.Triggers>

</Border>

</DataTemplate>

</Page.Resources>

...

</Page>

Now I want to throw the NextDocEvent from within c# code.
The definition of the Event:

Code Snippet

public static readonly RoutedEvent NextDocEvent = EventManager.RegisterRoutedEvent( "NextDoc", RoutingStrategy.Tunnel, typeof( RoutedEventHandler ), typeof( MyPage ) );

public event RoutedEventHandler NextDoc
{

add { AddHandler( NextDocEvent, value ); }

remove { RemoveHandler( NextDocEvent, value ); }

}

void RaiseNextDocEvent()
{

RoutedEventArgs newEventArgs = new RoutedEventArgs( MyPage.NextDocEvent );
RaiseEvent(newEventArgs);

}

this approach seems not to work because I get this Error:

Code Snippet

'MyPage.NextDocEvent' value cannot be assigned to property 'RoutedEvent' of object 'System.Windows.EventTrigger'. Value cannot be null.
Parameter name: value Error at object 'System.Windows.EventTrigger' in markup file

Catch Events from Within Templates

Wed, 15 Aug 2007 06:55:12 Z

Hello, you should use RoutedEvent="local:MyPage.NextDoc", not NextDocEvent. Just like you normally use RoutedEvent="Button.Click", not ClickEvent.

Catch Events from Within Templates

Wed, 15 Aug 2007 16:36:45 Z

stupid me! Of course.
Now it compiles but still the event is not catched.
if I call the Raise-Method the EventTrigger doesnt get the tunneled event it should shouldn't it?

Catch Events from Within Templates

Thu, 16 Aug 2007 03:31:03 Z

This works fine for me:

In the Window’s code behind, create a routed event:

public static readonly RoutedEvent TestEvent = EventManager.RegisterRoutedEvent("Test", RoutingStrategy.Tunnel, typeof(RoutedEventHandler), typeof(Window1));

public event RoutedEventHandler Test

{

add { AddHandler(TestEvent, value); }

remove { RemoveHandler(TestEvent, value); }

}

private void RaiseTestEvent()

{

RoutedEventArgs newEventArgs = new RoutedEventArgs(Window1.TestEvent);

RaiseEvent(newEventArgs);

}

Raise this event when clicking a Button (are you missing this step?):

private void Button1_Click(object sender, RoutedEventArgs e)

{

RaiseTestEvent();

}

Use an EventTrigger to handle this event:

</EventTrigger>

The animation plays successfully.

Catch Events from Within Templates

Thu, 16 Aug 2007 07:12:21 Z

Could it be that I cant catch the event because my EventTrigger is in a Template?

Catch Events from Within Templates

Thu, 16 Aug 2007 21:24:05 Z

I have a very similar situation. My post here explains this. Have you figured out what your issue is? I have been struggling with this for a while now - need to find some alternate solutions soon if I can't figure out what is going on.

I have double-checked and tripple checked for syntatic/spelling errors which the compiler might not catch and have found nothing. For some reason my DataTemplate is not catching the event even though I have verified that the ListBoxItem it is applied to can from code.

Any suggestions out there on how to debug this?

Catch Events from Within Templates

Tue, 21 Aug 2007 16:52:24 Z

DataTemplate is a NameScope (implements INameScope), so the SourceName in the EventTrigger is looking for myPageObj in the DataTemlate, not in the Page.

Thanks, Rob

Rob Relyea | Program Manager, WPF & Xaml Language Team
robrelyea.com | /blog | /wpf | /xaml

Catch Events from Within Templates

Wed, 22 Aug 2007 08:39:49 Z

Thanks Rob that was a slightly more helpful piece of information.
So i am in another scope.
Is there a Chance to Trigger that EvenTrigger from within other scopes?
Any solution is ok even a hacky one. I need to catch that Event in the templatescope else I have to work around and remove almost all my templates and work them into my definitions.
That would be good night DRY.