RoutedEventAttribute: How to handle a custom event args type?

[HavenDV]

Discussed in #61

^{Originally posted by fubar-coder August 27, 2024}
Hi,

the dependency property source generator stuff really works well. After that, I wanted to try the routed events, but I stumbled over the following problem:

Let's assume that I have an event handler delegate, like EventHandler<MyCustomEventArgs>, with MyCustomEventArgs being defined as:

public class MyCustomEventArgs : RoutedEventArgs
{
  public MyCustomEventArgs(int myValue)
  {
    MyValue = myValue;
  }

  public MyCustomEventArgs(int myValue, RoutedEvent evt)
    : base(evt)
  {
    MyValue = myValue;
  }

  public MyCustomEventArgs(int myValue, RoutedEvent evt, object? source)
    : base(evt, source)
  {
    MyValue = myValue;
  }

  public int MyValue { get; }
}

Now, I'd like to use the following attribute:

[RoutedEvent<EventHandler<MyCustomEventArgs>>("MyCustomEvent", RoutedEventStrategy.Bubble)]

The problem is, that it automatically generates a OnMyCustomEvent, which creates a RoutedEventArgs instead of the needed MyCustomEventArgs.

Is there a way to provide the correct event arguments?

[fubar-coder]

I'd suggest a simple option, which allows to specify your custom OnMyCustomEvent function name, which has the following effect of suppressing the automatic implementation of the default On* function. This would allow s/o to implement a custom function with the "correct" event arguments.