Dynamic button click event created OnPreRender doesn't fire

Question

I am creating a button dynamically in the PreRender event like this:

Button myButton = new Button();
myButton.Text = "Test";
myButton.Click += new EventHandler(myButton_Click);
myDiv.Controls.Add(myButton);

This button is render in the browser, but when I click the button, the click event doesn't fire. I tried to create an identical button in the PageLoad event and it works perfectly, but I must create this button it the PreRender event, since creating this dynamic button or not depends on a value which I get only in this event. What can I do so when I click a dynamic button created in the PreRender, the click event fires?

Answer 1

You should add your button to the page in the page's OnInit event and wire up it's click event during or before OnLoad and then you can enable/disable your button or make visible/invisible your button using the variable that you will have during the PreRender event. See Joel Coehoorn's answer to this question for more details. Otherwise try using a PlaceHolder control though that may end up being trickier.

protected override void OnInit (EventArgs e)
{
  Button myButton = new Button();
  myButton.Text = "Test";
  myButton.Click += new EventHandler(myButton_Click);
  myDiv.Controls.Add(myButton);

  base.OnInit(e);
}

protected override void OnPreRender(EventArgs e)
{
  myButton.Visible = myConditional;

  base.OnPreRender(e);
}