Check Box in header of Grid View

[hao]

Hi, i tried to follow this KB "how to add a checkbox header" to add a checkbox to the header of a checkboxcolumn of grid view
but when ever i try to scroll till the Column(which contains the Check box in its header) disappears behind the grid NullRefrenceException Happens in this method
 public override void Detach()
        {
            base.Detach();
            this.GridControl.ValueChanged -= GridControl_ValueChanged;
        }

im using the latest version

thank you

[Richard Slade]

Hello,

Please have a look at this forum answer which I am sure will solve your issue.
Regards,
Richard