Bindable UserControl stops updating when an event member is added

Troncho posted on Friday, November 09, 2012

[System.ComponentModel.DefaultBindingProperty("InfoObj")]

[DefaultEvent("InfoObjChanged")]

public partial class UCNrgHelpBase : UserControl

{

public event EventHandler<NrgHelpBaseEventArgs> InfoObjChanged;

public virtual IReadOnlyInfo InfoObj {...}

...

}

If I comment the event (InfoObjChanged), DataBinding works perfectly well.

If I just leave the event (InfoObjChanged) decleared,

even without using it anywhere, the control's bindable property

updates just fine but the DataSource property never gets updated.

Do you know what I may be missing here?

Thanks,

Troncho

I found the problem!

It seems that, behind the curtains, when you declare a class with the attribute:

[System.ComponentModel.DefaultBindingProperty("InfoObj")]

It generates some hidden event for DataBinding handling or something with the following name: [PropertyName + "Changed"].

So, when I declared the

public event EventHandler<NrgHelpBaseEventArgs> InfoObjChanged;

it seems to suppress the underlaying behaivour for DataBinding to work correctly.

Just fooling around, I begun changing EventHandler types and names, and I got it working.

The result being that I only changed my custom event handler's name to:

public event EventHandler<NrgHelpBaseEventArgs> InfoObj_ValueChanged;

And it all fall into place. Now DataBinding is working again just fine and my custom event is firing just as well.

So, problem seems to be solved.

Troncho