Unable to handle events of controls created at runtime

[Lalit]

Hi,

My application has two methods which creates buttons at runtime. In one
method I am able to handle the events of the buttons created at run time, but
in other I am not.

The code structure is as follows:

page_load
{
...Do something
CreateFirstSetOfButtons()
}

private CreateFirstSetOfButtons()
{
// Create first set of buttons
for { i=1; i<5; i++)
{
LinkButton newButton1 = new LinkButton();
newButton1.Click += new EventHandler(this.Button1_Click);
}
... Do something
}

// Event handler of first set of buttons. The second buttons are created on
click of first buttons click.
private void Button1_Click(object sender, System.EventArgs e)
{
CreateSecondSetOfButtons();
}
private CreateSecondSetOfButtons()
{
// Create first set of buttons
for { i=1; i<2; i++)
{
LinkButton newButton2 = new LinkButton();
newButton2.Click += new EventHandler(this.Button2_Click); // This event
is never getting fired.
}
... Do something
}

private void Button2_Click(object sender, System.EventArgs e)
{
Response.Write("Hello");
}

On click of buttons created at page load I am able to catch the Click evet
of those buttons and the second set of buttons gets created. But when I click
on this second set of created buttons, the statement
Response.Write("Hello"); never gets executed.

An early resolution for the same will be really helpful.

Regards
Lalit

 

[aidan.s.marcuss]

I suspect this has to do with binding the event handlers too late.
Take a look at:
http://msdn.microsoft.com/library/d...guide/html/cpconcontrolexecutionlifecycle.asp

While not crystal clear, I would guess that because your controls are
present during the "LoadPostData" method, they aren't able to take
part in post back events. I've seen a similar problem manifested in
many ways while working with ASP.NET. In order for a dynamically
created control to take part in PostBack and ViewState fully, it must
be created and be part of the Page's Control hierarchy (either directly
or as part of the Controls collection some other control which is
eventually a part of the Page's Control collection).

My role has been for the past few years to always create dynamc
controls during the Init event.

Hope this helps,
Aidan

 

[aidan.s.marcuss]

I suspect this has to do with binding the event handlers too late.
Take a look at:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpgu...

While not crystal clear, I would guess that because your controls are
not
present during the "LoadPostData" method, they aren't able to take
part in post back events. I've seen a similar problem manifested in
many ways while working with ASP.NET. In order for a dynamically
created control to take part in PostBack and ViewState fully, it must
be created and be part of the Page's Control hierarchy (either directly
or as part of the Controls collection some other control which is
eventually a part of the Page's Control collection) by the time the
Init event is done.

My rule has been for the past few years to always create dynamc
controls during the Init event.

Hope this helps,
Aidan