Try the CurrentCellShowedDropDown event. This code worked for me in the DropDownGrid sample. And it also worked when I switched the dropped grid to a GriddataBoundGrid.
private void gridControl1_CurrentCellShowedDropDown(object sender, System.EventArgs e)
{
GridCurrentCell cc = this.gridControl1.CurrentCell;
if(this.gridControl1[cc.RowIndex, cc.ColIndex].CellType == "GridADropCell")
{
GridA.Focus();
GridA.ForceCurrentCellMoveTo = true;
GridA.CurrentCell.MoveTo(1,1);
}
}
Without the focus call, the currentcell shows with a dotted border meaning the grid does not have focus.