Intellisense not working in XAML if used on a Custom event handler

Question

I created a UserControl and a fully custom (args, handler, event) event for it:

public partial class UserControl1 : UserControl {

public UserControl1() {

InitializeComponent();

}

public static RoutedEvent AreaSelectedEvent =

EventManager.RegisterRoutedEvent("AreaSelected", RoutingStrategy.Bubble, typeof(AreaSelectEventHandler), typeof(UserControl1));

public event AreaSelectEventHandler AreaSelected { add { AddHandler(AreaSelectedEvent, value); } remove { RemoveHandler(AreaSelectedEvent, value); } }

protected virtual void OnAreaSelected() {

RoutedEventArgs args = new AreaSelectEventArgs() { RoutedEvent = AreaSelectedEvent, Source = this };

RaiseEvent(args);

}

}

public delegate void AreaSelectEventHandler(object sender, AreaSelectEventArgs e);

public class AreaSelectEventArgs : RoutedEventArgs {}

It is working as intended but, if I use the UserControl in XAML, the XAML editor does not help me. ie: it is not creating the event handler for the custom event. It shows (lists) the event in the popul list, and creates what you see below:

<Window x:Class="Test.Window1"

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

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

xmlns:local="clr-namespace:Test"

Title="Window1" Height="300" Width="300">

<Grid>

<local:UserControl1 AreaSelected="|" />

</Grid>

</Window>

If I place the cursor where the pipe (|) is and press Control+Space it does not show anything and complains about the empty string. If I fill it in like: <local:UserControl1 AreaSelected="uc_AreaSelected" /> and right click it and press Navigate to evnt handler... it tells me:
Unable to navigate to event handler. Valid event assignment not found. Select an event handler in the XAML and try again.
even if I create an event handler like so: public void uc_AreaSelected(object sender, AreaSelectEventArgs e) {}

Why is it not working what am I doing wrong when creating custom event and/or using the User control?

Comment:
At some place (ScrollEventArgs) I saw that it's implemented like this (which does not help either):

protected override void InvokeEventHandler(Delegate genericHandler, object genericTarget) {

AreaSelectEventHandler handler = (AreaSelectEventHandler)genericHandler;

handler(genericTarget, this);

}

I don't know why it is needed, but I think it is to make sure (by casting which throws Exception) that the right type of handler is used.

Answer 1

Hi, did you find a solution why the intellisense isn't working? At the moment I'm facing the same problem...maybe there is a missing class attribute.

Greets, Michael

Answer 2

Aw..I got it: Instead of using 

public   event  AreaSelectEventHandler AreaSelected

you have to write:

public   event EventHandler<AreaSelectedEventArgs> AreaSelected

and also when registering this event:

public   static  RoutedEvent AreaSelectedEvent =

EventManager.RegisterRoutedEvent( "AreaSelected" , RoutingStrategy.Bubble,  typeof (EventHandler< AreaSelectEventArgs> ),  typeof (UserControl1));

Now, your Intellisense inside XAML will be working fine!