How to always display the WinForms GridListControl drop-down of the same size?

//Trigger the Events.
this.gridGroupingControl1.QueryCellStyleInfo += new GridTableCellStyleInfoEventHandler(gridGroupingControl1_QueryCellStyleInfo);
this.gridGroupingControl1.TableControlCurrentCellShowingDropDown += new GridTableControlCurrentCellShowingDropDownEventHandler(gridGroupingControl1_TableControlCurrentCellShowingDropDown);

void gridGroupingControl1_TableControlCurrentCellShowingDropDown(object sender, GridTableControlCurrentCellShowingDropDownEventArgs e)
{
    int defaultHeight = 18;
    //Dropdown size change for column 3.
    if (isitem1)
    {
        if (this.gridGroupingControl1.TableModel.CurrentCellRenderer != null && this.gridGroupingControl1.TableModel.CurrentCellRenderer is GridDropDownGridListControlCellRenderer)
        {                   
            GridDropDownGridListControlCellRenderer listRenderer =
(GridDropDownGridListControlCellRenderer)this.gridGroupingControl1.TableModel.CurrentCellRenderer;
            e.Inner.Size = new Size(200, (dr.Table.Rows.Count * defaultHeight));//Set the height based on the items.
            listRenderer.ListControlPart.ShowColumnHeader = false;
        }
    }
    //Dropdown size change for column 4.
    else if (isitem2)
        if (this.gridGroupingControl1.TableModel.CurrentCellRenderer != null && this.gridGroupingControl1.TableModel.CurrentCellRenderer is GridDropDownGridListControlCellRenderer)
        {
            GridDropDownGridListControlCellRenderer listRenderer =
(GridDropDownGridListControlCellRenderer)this.gridGroupingControl1.TableModel.CurrentCellRenderer;
            e.Inner.Size = new Size(300, (dr1.Table.Rows.Count * defaultHeight));//Set the height based on the items
            listRenderer.ListControlPart.ShowColumnHeader = false;
        }
}

bool isitem1, isitem2;
void gridGroupingControl1_QueryCellStyleInfo(object sender, GridTableCellStyleInfoEventArgs e)
{
    //GridListControl cell type assigned for column 4.
    if (e.TableCellIdentity.RowIndex > 2 && e.TableCellIdentity.ColIndex == 4)
    {
        e.Style.CellType = "GridListControl";
        e.Style.DataSource = this.ReturnATable();
        e.Style.DisplayMember = "LastName";
        isitem2 = true;
        isitem1 = false;
    }
    //GridListControl cell type assigned for column 3.
    if (e.TableCellIdentity.RowIndex > 2 && e.TableCellIdentity.ColIndex == 3)
    {
        e.Style.CellType = "GridListControl";
        e.Style.DataSource = this.table();
        e.Style.DisplayMember = "FirstName";
        isitem1 = true;
        isitem2 = false;
    }
}

'Trigger the Events.
AddHandler Me.gridGroupingControl1.QueryCellStyleInfo, AddressOf gridGroupingControl1_QueryCellStyleInfo
AddHandler Me.gridGroupingControl1.TableControlCurrentCellShowingDropDown, AddressOf gridGroupingControl1_TableControlCurrentCellShowingDropDown

Private Sub gridGroupingControl1_TableControlCurrentCellShowingDropDown(ByVal sender As Object, ByVal e As GridTableControlCurrentCellShowingDropDownEventArgs)
            Dim defaultHeight As Integer = 18
            'Dropdown size change for column 3
            If isitem1 Then
                If Me.gridGroupingControl1.TableModel.CurrentCellRenderer IsNot Nothing AndAlso TypeOf Me.gridGroupingControl1.TableModel.CurrentCellRenderer Is GridDropDownGridListControlCellRenderer Then
                    Dim listRenderer As GridDropDownGridListControlCellRenderer = CType(Me.gridGroupingControl1.TableModel.CurrentCellRenderer, GridDropDownGridListControlCellRenderer)
                    e.Inner.Size = New Size(200, (dr.Table.Rows.Count * defaultHeight)) 'Set the height based on the items
                    listRenderer.ListControlPart.ShowColumnHeader = False
                End If
           'Drop down size change for column 4
            ElseIf isitem2 Then
                If Me.gridGroupingControl1.TableModel.CurrentCellRenderer IsNot Nothing AndAlso TypeOf Me.gridGroupingControl1.TableModel.CurrentCellRenderer Is GridDropDownGridListControlCellRenderer Then
                    Dim listRenderer As GridDropDownGridListControlCellRenderer = CType(Me.gridGroupingControl1.TableModel.CurrentCellRenderer, GridDropDownGridListControlCellRenderer)
                     e.Inner.Size = New Size(300, (dr1.Table.Rows.Count * defaultHeight)) 'Set the height based on the items
                      listRenderer.ListControlPart.ShowColumnHeader = False
          End If
      End If
End Sub

Private isitem1, isitem2 As Boolean
Private Sub gridGroupingControl1_QueryCellStyleInfo(ByVal sender As Object, ByVal e As GridTableCellStyleInfoEventArgs)
          'GridListControl cell type assigned for column 4
           If e.TableCellIdentity.RowIndex > 2 AndAlso e.TableCellIdentity.ColIndex = 4 Then
                e.Style.CellType = "GridListControl"
                e.Style.DataSource = Me.ReturnATable()
                e.Style.DisplayMember = "LastName"
                isitem2 = True
                isitem1 = False
           End If
            'GridListControl cell type assigned for column 3
           If e.TableCellIdentity.RowIndex > 2 AndAlso e.TableCellIdentity.ColIndex = 3 Then
                e.Style.CellType = "GridListControl"
                e.Style.DataSource = Me.table()
                e.Style.DisplayMember = "FirstName"
                isitem1 = True
                isitem2 = False
           End If
End Sub