“SelectedIndexChanged” event in ComboBoxColumn on Datagridview

Question

I want to handle this event \"SelectedIndexChanged\" on a DataGridViewComboBoxColumn, and I set it on \"EditingControlShowing\" event of the gridview.

The problem :

Answer 1

Things get complicated since they optimized the DataGridView by only having one editing control for all the rows. Here's how I handled a similar situation:

First hook up a delegate to the EditControlShowing event:

myGrid.EditingControlShowing += new DataGridViewEditingControlShowingEventHandler(
                                    Grid_EditingControlShowing);
...

Then in the handler, hook up to the EditControl's SelectedValueChanged event:

void Grid_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
    ComboBox combo = e.Control as ComboBox;
    if (combo != null)
    {
        // the event to handle combo changes
        EventHandler comboDelegate = new EventHandler(
            (cbSender, args) =>
            {
                DoSomeStuff();
            });

        // register the event with the editing control
        combo.SelectedValueChanged += comboDelegate;

        // since we don't want to add this event multiple times, when the 
        // editing control is hidden, we must remove the handler we added.
        EventHandler visibilityDelegate = null;
        visibilityDelegate = new EventHandler(
            (visSender, args) =>
            {
                // remove the handlers when the editing control is
                // no longer visible.
                if ((visSender as Control).Visible == false)
                {
                    combo.SelectedValueChanged -= comboDelegate;
                    visSender.VisibleChanged -= visibilityDelegate;
                }
            });

        (sender as DataGridView).EditingControl.VisibleChanged += 
           visibilityDelegate;

    }
}