Comanighttrain Comanighttrain - 10 days ago 8
ASP.NET (C#) Question

Dynamically (programatically) adding check boxes and checkedchanged events

I am having a bit of a problem adding a few check boxes and an event handler programatically. The check boxes all appear fine, but they don't do anything when clicked. Does anyone have any idea what I am doing wrong?

My code:



foreach (Statement i in theseStatements)
{
box = new CheckBox();
box.Text = i.StatementText;
box.AutoPostBack = true;
box.CheckedChanged += new EventHandler(this.CheckedChange);
PlaceHolder.Controls.Add(box);
}

protected void CheckedChange(object sender, EventArgs e)
{
CheckBox x = (CheckBox)sender;
Instructions.Text = "change";
WorkPlaceHazardsBox.Text += x.Text;
}

Answer

You should do the following:

  1. Set the ID property for each instance of CheckBox you create in your foreach loop.
  2. For PostBacks, ensure that your CheckBoxes are created and CheckedChanged event handler is attached at some point of the page life-cycle before control events are raised
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