C# Datagridview Column Header Double Click
// If you want the event to NOT work on Header Double Click
private void itemsList_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
{
if(e.RowIndex>-1)
HereIsNotHeader();
}
// If you want the event to ONLY work on Header Double Click
private void itemsList_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
{
if(e.RowIndex == -1)
HereIsHeader();
}