Help on eventhandler

[phinoppix]

I read this article about imitating VB6's control arrays on C#. What it suggested is this: Assuming I am trying to employ a single Click event on multiple buttons - b1, b2, b3 - I would instantiate a Button class (bx) and create its eventhandler. Then, I add eventhandlers to these (b1, b...) pointing to bx's.

this.b1.Click += EventHandler(bx_Click);
this.b2.Click += EventHandler(bx_Click);

It worked, but I'm stopped on one question: How do I know who's the sender? I mean how do I use the sender par to identify who's b1 or b2 or b3?

Well, I know they have their Name property, but are there better (cleaner) approach on this?

[tt]
private void bx_Click(object sender, EventArgs e)
{
Button btnHndr;
btnHndr = (Button)sender;
switch(btnHndr.Name)
{
case "b1":
MessageBox.Show("Button 1"
break;
case "b2":
MessageBox.Show("Button 2"
break;
case "b3":
MessageBox.Show("Button 3"
break;
}
}[/tt]

TIA,

 

[kelviny]

You've pretty much got it. You could improve your current example slightly (see below), but in most cases you will find yourself using a switch block.

private void bx_Click(object sender, EventArgs e)
{
Button btnHndr;
btnHndr = (Button)sender;
MessageBox.Show(btnHndr.Text);
}

 

[tgreer]

I suggest using the .GetHashCode() method. That will give you a unique ID for each button. Compare that to Sender.GetHashCode(). If the sender's hashcode matches a particular button... that button generated your event.

Thomas D. Greer

http://www.tgreer.com