How to show the dropdown list when a key is pressed in the ComboBox cell in WinForms GridControl?

this.gridControl1.CurrentCellKeyPress += new KeyPressEventHandler(gridControl1_CurrentCellKeyPress);
void gridControl1_CurrentCellKeyPress(object sender, KeyPressEventArgs e)
{         
    //Checks whether the cell type is ComboBox or not.
    if (this.gridControl1[this.gridControl1.CurrentCellInfo.RowIndex, this.gridControl1.CurrentCellInfo.ColIndex].CellType == GridCellTypeName.ComboBox)
    {
        //Enables the show dropdown in the current cell.
        this.gridControl1.CurrentCell.ShowDropDown();
    }
}

Private Me.gridControl1.CurrentCellKeyPress += New KeyPressEventHandler(AddressOf gridControl1_CurrentCellKeyPress)
Private Sub gridControl1_CurrentCellKeyPress(ByVal sender As Object, ByVal e As KeyPressEventArgs)
  'Checks whether the cell type is ComboBox or not.
  If Me.gridControl1(Me.gridControl1.CurrentCellInfo.RowIndex, Me.gridControl1.CurrentCellInfo.ColIndex).CellType Is GridCellTypeName.ComboBox Then
    'Enables the show dropdown in the current cell.
    Me.gridControl1.CurrentCell.ShowDropDown()
  End If
End Sub