void setSecondColumnDropDownListButton_Click(object sender, EventArgs e)
        {
            // Create a header drop down list without default down down items.
            HeaderDropDownList headerDropDownList = new HeaderDropDownList();

            // If do not indicate which cell to be filtered, the cell which has same index with column header cell in row section will be filtered.
            headerDropDownList.CellName = "textBoxCell2";

            DropDownItemCollection dropDownItemCollection = headerDropDownList.Items;
            // Initialize drop down items manually.
            // Add sort item.
            dropDownItemCollection.Add(new DropDownSortItem(SortOrder.Ascending));
            dropDownItemCollection.Add(new DropDownSortItem(SortOrder.Descending));
            
            // Add a separator line.
            dropDownItemCollection.Add(new DropDownSeparatorItem());

            // Add show all, black and none black items.
            dropDownItemCollection.Add(new DropDownShowAllFilterItem());
            dropDownItemCollection.Add(new DropDownBlanksFilterItem());
            dropDownItemCollection.Add(new DropDownNonBlanksFilterItem());

            // Add auto filter items.
            dropDownItemCollection.Add(new DropDownAutoFilterItem());

            // Get second column header cell.
            ColumnHeaderCell columnHeaderCell = this.gcMultiRow1.ColumnHeaders[0][1] as ColumnHeaderCell;
            columnHeaderCell.DropDownList = headerDropDownList;
        }