public class CalendarGcTextBoxCellType : CalendarInputManCellBaseType 

using System;
using System.Windows.Forms;
using System.Drawing;
using GrapeCity.Win.CalendarGrid.InputMan;
using GrapeCity.Win.CalendarGrid;

namespace CalendarGridSampleCode
{
    class GcTextBoxCellDemo : Form
    {
        private GcCalendarGrid gcCalendarGrid1 = new GcCalendarGrid();
        private Label label = new Label();

        public GcTextBoxCellDemo()
        {
            this.Text = "GcTextBoxCell Demo";
            this.Size = new Size(350, 300);

            // Add GcCalendarGrid to form
            this.gcCalendarGrid1.Dock = DockStyle.Fill;
            this.Controls.Add(this.gcCalendarGrid1);

            this.label.Dock = DockStyle.Bottom;
            this.label.Height = 50;
            this.label.BackColor = SystemColors.Info;
            this.label.Text = "You can only input upper and lower case alphabet, as well as the symbols. Except '#', '@' and '*' chars; The DropDownButton will show when GcTextBoxCell is CurrentCell, and you can switch the DropDownList through hitting the F4 in edit mode.";
            this.Controls.Add(label);

            this.Load += Form1_Load;

            this.StartPosition = FormStartPosition.CenterScreen;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // Create an instance of a GcTextBox control.
            CalendarGcTextBoxCellType gcTextBoxCell1 = new CalendarGcTextBoxCellType();
            // Accept upper and lower case alphabet, as well as the symbols. Except '#', '@' and '*' chars.
            gcTextBoxCell1.Format = @"aA@^\#\@*";
            // The GcTextBox will try to convert the invalid char to valid char automatically.
            gcTextBoxCell1.AutoConvert = true;

            DropDownButton dropDownButton1 = new DropDownButton();
            dropDownButton1.Visible = CalendarCellButtonVisibility.ShowForCurrentCell;
            gcTextBoxCell1.SideButtons.Add(dropDownButton1);

            CalendarTemplate template1 = CalendarTemplate.CreateDefaultTemplate();
            template1.Content[1, 0].CellType = gcTextBoxCell1;
            template1.Content[2, 0].CellType = gcTextBoxCell1.Clone();
            gcCalendarGrid1.Template = template1;
        }

        [STAThreadAttribute()]
        public static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new GcTextBoxCellDemo());
        }
    }
}