Re: this cf sender in event handlers

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Hmm, I suppose I should have been more precise by pointing out that "sender
as MyButton" does not return null - hence sender is definitely an instance
of MyButton (as expected since the event is actually raised by clicking the
button in question) - but apparently not (always) the same instance as
"this".

I see that another respondent found the assertion not to fail in their
testing, so I remain at a loss. Perhaps the question should be rephrased
as: Under what circumstances might the assertion be made to fail?

thanks,

gary

--
http://www.oxide.net.au
"Jon Skeet [C# MVP]" <skeet@xxxxxxxxx> wrote in message
news:MPG.20d6fcf1fc6e04971ff@xxxxxxxxxxxxxxxxxxxxxxx
Gary Stephenson <gary@xxxxxxxxxxxx> wrote:
Can someone please explain why the assertion in the following code fails?
Could the assertion be made to succeed somehow?

// code begins

class MyButton : Button
{
public MyButton()
{
Click += HandleClick ;
}

public void HandleClick( object sender, EventArgs e)
{
Debug.Assert( Object.ReferenceEquals( sender as MyButton, this )
;
// why does this fail?
}
}

Well, the first thing to do would be to look at what the sender
*actually* is.

--
Jon Skeet - <skeet@xxxxxxxxx>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too


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