Hi,

The problem here is that the event is firing on the KeyDown event and so the KeyUp gets triggered on the new dialog you showed and it is being handled by the control with focus at the time, which is the button (since it's the only control on form2).

Also, this has nothing to do with the problem you are having, but it's really not a good idea to hook into events on the column's editor. If you want to trap when the user changes the CheckBox, then you should use the CellChange event of the grid.

To avoid the KeyUp problem, I tried launching the dialog via a BeginInvoke instead of doing it directly inside the event. That way all of the keyboard processing completes before the dialog is displayed.But it does not work. I think this might be because there is another timing issue going on here with yuor handling of the grid's KeyDown event to put the cell into edit mode.

If you tell me what you are trying to achieve, exactly, then perhaps I could help you achieve it. But right now, it's a bit unclear. It looks like you don't want anything in the grid to be editable and you are just using the to select a list of rows using the checkbox column. So all you really want is for the spacebar to toggle the checkbox and show a dialog. If that's the case, then I think it makes more sense to simply toggle the checkbox in the KeyUp event of the grid rather than putting the cell into edit mode in KeyDown.

        private void ultraGrid1_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Space)
            {
                if (ultraGrid1.ActiveRow != null)
                {
                    this.ultraGrid1.ActiveRow.Cells["Flag"].Value = !((bool)this.ultraGrid1.ActiveRow.Cells["Flag"].Value);
                    this.ShowForm2();
                }
            }
        }

        private void ShowForm2()
        {
            using (var form2 = new Form2())
            {
                form2.ShowDialog();
            }
        }