public class ComboBoxCell : ListCell 

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Data;

namespace GrapeCity.Win.MultiRow.SampleCode
{
    public class ComboBoxCellDemo : Form
    {
        private GcMultiRow gcMultiRow1 = new GcMultiRow();
        
        private Label descriptionLable = new Label();

        public ComboBoxCellDemo()
        {
            this.Text = "ComboBoxCell Demo";
            this.Size = new Size(400, 300);

            // Add MultiRow to form
            this.gcMultiRow1.Dock = DockStyle.Fill;
            this.Controls.Add(this.gcMultiRow1);

            descriptionLable.Height = 40;
            descriptionLable.BackColor = SystemColors.Info;
            descriptionLable.Dock = DockStyle.Bottom;
            this.Controls.Add(descriptionLable);

            this.gcMultiRow1.CellEnter += new EventHandler<CellEventArgs>(gcMultiRow1_CellEnter);
            this.Load += new EventHandler(Form1_Load);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // create a template with 4 combo box cell columns.
            ComboBoxCell unboundComboCell = this.CreateCommonComboBoxCell();

            ComboBoxCell dataBindingComboCell = this.CreateDatabindingComboBoxCell();

            ComboBoxCell autoCompleteComboCell = this.CreateAutoCompleteComboBoxCell();

            ComboBoxCell hiddenDropDownButtonComboCell = this.CreateComboBoxCellHiddenDropDownButton();

            Cell[] comboBoxCells = new Cell[] { unboundComboCell, dataBindingComboCell, autoCompleteComboCell, hiddenDropDownButtonComboCell };

            this.gcMultiRow1.Template = Template.CreateGridTemplate(comboBoxCells);

            this.gcMultiRow1.ColumnHeaders[0][0].Value = "Common";
            this.gcMultiRow1.ColumnHeaders[0][1].Value = "Databinding";
            this.gcMultiRow1.ColumnHeaders[0][2].Value = "AutoComplete";
            this.gcMultiRow1.ColumnHeaders[0][3].Value = "Hide Button";

            this.gcMultiRow1.RowCount = 6;
        }

        ComboBoxCell CreateCommonComboBoxCell()
        {
            ComboBoxCell comboBoxCell = new ComboBoxCell();
            
            // The item which listed in drop down window. 
            comboBoxCell.Items.AddRange("Item2", "Item1", "Item3", "Item4", "Long Item to Make Ellipsis Show");

            // Sort items.
            comboBoxCell.Sorted = true;

            // Drop down window's width, in default, the value is equals to cell's width.
            comboBoxCell.DropDownWidth = 100;

            // In non edit status, if text's length bigger than cell's width, EllipsisString will be shown.
            comboBoxCell.Ellipsis = MultiRowEllipsisMode.EllipsisEnd;

            return comboBoxCell;
        }

        ComboBoxCell CreateDatabindingComboBoxCell()
        {
            DataTable dataTable = this.CreatDataTable();

            ComboBoxCell comboBoxCell = new ComboBoxCell();

            // Binding items to a data source.
            comboBoxCell.DataSource = dataTable;

            // The column "Name" of data source will be use to display in the drop down list.
            comboBoxCell.DisplayMember = "Name";

            // When user select a value, the corresponding "ID" will be save as cell's value.
            comboBoxCell.ValueMember = "ID";

            return comboBoxCell;
        }

        private DataTable CreatDataTable()
        {
            DataTable dataTable = new DataTable();
            dataTable.Columns.Add("ID", typeof(int));
            dataTable.Columns.Add("Name", typeof(string));

            dataTable.Rows.Add(0, "Barry");
            dataTable.Rows.Add(1, "Colin");
            dataTable.Rows.Add(2, "Robert");
            dataTable.Rows.Add(3, "Walter");
            dataTable.Rows.Add(4, "Wedy");

            return dataTable;
        }

        ComboBoxCell CreateAutoCompleteComboBoxCell()
        {
            ComboBoxCell comboBoxCell = new ComboBoxCell();

            comboBoxCell.DropDownStyle = MultiRowComboBoxStyle.DropDown;
            comboBoxCell.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
            comboBoxCell.AutoCompleteSource = AutoCompleteSource.CustomSource;
            string[] customSourceItems = new string[] { "aaa", "bbb", "ccc", "ddd" };
            comboBoxCell.AutoCompleteCustomSource.AddRange(customSourceItems);

            comboBoxCell.Items.AddRange("(none)", "aaa", "bbb", "ccc", "ddd");

            return comboBoxCell;
        }

        ComboBoxCell CreateComboBoxCellHiddenDropDownButton()
        {
            ComboBoxCell comboBoxCell = new ComboBoxCell();

            comboBoxCell.DropDownStyle = MultiRowComboBoxStyle.DropDown;

            // Hide drop down button when non edit status.
            comboBoxCell.ShowDropDownButton = CellButtonVisibility.NotShown;

            comboBoxCell.Items.AddRange("Item1", "Item2");

            return comboBoxCell;
        }

        void gcMultiRow1_CellEnter(object sender, CellEventArgs e)
        {
            switch (e.CellIndex)
            {
                case 0:
                    descriptionLable.Text = "Common combo box cell setting. You can click the cell to show drop down list, and select a item in the list to edit cell";
                    break;
                case 1:
                    descriptionLable.Text = "The combo box cell binding to a data table which have two columns 'ID' and 'Name', drop list will lists 'Name', and when you select a item, 'ID' will be stored.";
                    break;
                case 2:
                    descriptionLable.Text = "When you input some char, the cell will show some recommended values. Try input 'a' or 'b' and watch what happened";
                    break;
                default:
                    descriptionLable.Text = "Combo box cell hide its drop down button";
                    break;
            }
        }
               
        [STAThreadAttribute()]
        public static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new ComboBoxCellDemo());
        }
    }
}