private void RadForm1_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'nwindDataSet.Orders' table. You can move, or remove it, as needed.
            this.ordersTableAdapter.Fill(this.nwindDataSet.Orders);

            this.radMultiColumnComboBox1.DisplayMember = "OrderID";
            this.radMultiColumnComboBox1.ValueMember = "OrderID";
            this.radMultiColumnComboBox1.DataSource = ((DataSet)ordersBindingSource.DataSource).Tables[0].AsEnumerable().Reverse().Take(5);
             

            this.radMultiColumnComboBox1.UseCompatibleTextRendering = false;
            foreach (GridViewColumn col in this.radMultiColumnComboBox1.EditorControl.Columns)
            {
                if (!col.Name.Contains("ID") && !col.Name.Contains("OrderDate"))
                {
                    col.IsVisible = false;
                }
            }
            this.radMultiColumnComboBox1.AutoSizeDropDownColumnMode = BestFitColumnMode.AllCells;
            this.radMultiColumnComboBox1.AutoSizeDropDownToBestFit = true;

            return;  
        }

            List<string> columnNames = new List<string>();
            foreach (GridViewColumn col in this.radMultiColumnComboBox1.EditorControl.Columns)
            {
                if (!col.Name.Contains("ID") && !col.Name.Contains("OrderDate"))
                {
                    columnNames.Add(col.Name);
                    //col.IsVisible = false;
                }
            }
            while (columnNames.Count>0)
            {
                this.radMultiColumnComboBox1.Columns.Remove(columnNames[0]);
                columnNames.RemoveAt(0);
            }