select multiple checkbox in gridview in asp.net not working

Question

I am using this code to select multiple checkbox in GridView in asp.net but it is not working

protected void cbheader_CheckedChanged(object sender, EventArgs e)
{

    foreach (GridViewRow gridViewRow in GridView1.Rows)
    {
        ((CheckBox)gridViewRow.FindControl("chkcol"))
               .Checked = ((CheckBox)sender).Checked;
    }

}

Answer 1

For me it is a nonsense to do a postback (generating traffic) only to check few checkboxes... IMHO it is better to use javascript.

Here there are some examples: multiple checkboxes inside a GridView q using jquery , checkbox as template column and last one

Answer 2

Try JavaScript to check all checkboxes in DataGrid. Postback requests is not a good idea to solve this. There is a good example of how to implement such functionality using JavaScript: Implement check all checkbox functionality in ASP.Net GridView control using JavaScript