Add Dynamic CheckBox Handle CheckedChanged Event ASP.NET

Question

I would like to know why the event is not firing & how to find which checkbox control fired the event.

chkList1 = new CheckBox();
                            chkList1.Text = row["subj_nme"].ToString();
                            chkList1.ID = row["subjid"].ToString();
                            chkList1.Checked = true;
                            chkList1.Font.Name = "Verdana";
                            chkList1.Font.Size = 12;
                            chkList1.AutoPostBack = true;
                            chkList1.CheckedChanged += new EventHandler(CheckBox_CheckedChanged);
                            Panel1.Controls.Add(chkList1);

protected void CheckBox_CheckedChanged(object sender, EventArgs e)
            {
                Label1.Text = "Called";
            }

Where do you create the Checkbox dynamically? Do you recreate it also on postbacks in page_load at the latest with the same ID as before? — Tim Schmelter
– Tim Schmelter, Commented May 6, 2012 at 19:04
The object sender is the check box that triggered the event when you clicked on it. Just cast it to CheckBox. — fero
– fero, Commented May 6, 2012 at 21:41

James Johnson · Accepted Answer · 2012-05-06 22:55:19Z

2

If the events aren't firing, it's likely for one of two reasons:

The controls are recreated too late in the page lifecycle. Try creating the controls during OnInit.
Validation is preventing the postback. To work around this you can set CausesValidation to false on all of the CheckBox controls.

You can find out which control triggered the event using the sender argument.

protected void CheckBox_CheckChanged(object sender, EventArgs e)
{
    //write the client id of the control that triggered the event
    Response.Write(((CheckBox)sender).ClientID);
}

edited May 6, 2012 at 22:55

answered May 6, 2012 at 22:48

James Johnson

46.1k8 gold badges75 silver badges111 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Add Dynamic CheckBox Handle CheckedChanged Event ASP.NET

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related