using System;

using System.Windows.Forms;

public class CalendarColumn : DataGridViewColumn

{

    public CalendarColumn() : base(new CalendarCell())

    {

    }

    public override DataGridViewCell CellTemplate

    {

        get

        {

            return base.CellTemplate;

        }

        set

        {

            // Ensure that the cell used for the template is a CalendarCell.

            if (value != null &&

                !value.GetType().IsAssignableFrom(typeof(CalendarCell)))

            {

                throw new InvalidCastException("Must be a CalendarCell");

            }

            base.CellTemplate = value;

        }

    }

}

public class CalendarCell : DataGridViewTextBoxCell

{

    public CalendarCell()

        : base()

    {

        // Use the short date format.

        this.Style.Format = "d";

    }

    public override void InitializeEditingControl(int rowIndex, object

        initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)

    {

        // Set the value of the editing control to the current cell value.

        base.InitializeEditingControl(rowIndex, initialFormattedValue,

            dataGridViewCellStyle);

        CalendarEditingControl ctl =

            DataGridView.EditingControl as CalendarEditingControl;

        ctl.Value = (DateTime)this.Value;

    }

    public override Type EditType

    {

        get

        {

            // Return the type of the editing contol that CalendarCell uses.

            return typeof(CalendarEditingControl);

        }

    }

    public override Type ValueType

    {

        get

        {

            // Return the type of the value that CalendarCell contains.

            return typeof(DateTime);

        }

    }

    public override object DefaultNewRowValue

    {

        get

        {

            // Use the current date and time as the default value.

            return DateTime.Now;

        }

    }

}

class CalendarEditingControl : DateTimePicker, IDataGridViewEditingControl

{

    DataGridView dataGridView;

    private bool valueChanged = false;

    int rowIndex;

    public CalendarEditingControl()

    {

        this.Format = DateTimePickerFormat.Short;

    }

    // Implements the IDataGridViewEditingControl.EditingControlFormattedValue

    // property.

    public object EditingControlFormattedValue

    {

        get

        {

            return this.Value.ToShortDateString();

        }

        set

        {

            String newValue = value as String;

            if (newValue != null)

            {

                this.Value = DateTime.Parse(newValue);

            }

        }

    }

    // Implements the

    // IDataGridViewEditingControl.GetEditingControlFormattedValue method.

    public object GetEditingControlFormattedValue(

        DataGridViewDataErrorContexts context)

    {

        return EditingControlFormattedValue;

    }

    // Implements the

    // IDataGridViewEditingControl.ApplyCellStyleToEditingControl method.

    public void ApplyCellStyleToEditingControl(

        DataGridViewCellStyle dataGridViewCellStyle)

    {

        this.Font = dataGridViewCellStyle.Font;

        this.CalendarForeColor = dataGridViewCellStyle.ForeColor;

        this.CalendarMonthBackground = dataGridViewCellStyle.BackColor;

    }

    // Implements the IDataGridViewEditingControl.EditingControlRowIndex

    // property.

    public int EditingControlRowIndex

    {

        get

        {

            return rowIndex;

        }

        set

        {

            rowIndex = value;

        }

    }

    // Implements the IDataGridViewEditingControl.EditingControlWantsInputKey

    // method.

    public bool EditingControlWantsInputKey(

        Keys key, bool dataGridViewWantsInputKey)

    {

        // Let the DateTimePicker handle the keys listed.

        switch (key & Keys.KeyCode)

        {

            case Keys.Left:

            case Keys.Up:

            case Keys.Down:

            case Keys.Right:

            case Keys.Home:

            case Keys.End:

            case Keys.PageDown:

            case Keys.PageUp:

                return true;

            default:

                return false;

        }

    }

    // Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit

    // method.

    public void PrepareEditingControlForEdit(bool selectAll)

    {

        // No preparation needs to be done.

    }

    // Implements the IDataGridViewEditingControl

    // .RepositionEditingControlOnValueChange property.

    public bool RepositionEditingControlOnValueChange

    {

        get

        {

            return false;

        }

    }

    // Implements the IDataGridViewEditingControl

    // .EditingControlDataGridView property.

    public DataGridView EditingControlDataGridView

    {

        get

        {

            return dataGridView;

        }

        set

        {

            dataGridView = value;

        }

    }

    // Implements the IDataGridViewEditingControl

    // .EditingControlValueChanged property.

    public bool EditingControlValueChanged

    {

        get

        {

            return valueChanged;

        }

        set

        {

            valueChanged = value;

        }

    }

    // Implements the IDataGridViewEditingControl

    // .EditingPanelCursor property.

    public Cursor EditingPanelCursor

    {

        get

        {

            return base.Cursor;

        }

    }

    protected override void OnValueChanged(EventArgs eventargs)

    {

        // Notify the DataGridView that the contents of the cell

        // have changed.

        valueChanged = true;

        this.EditingControlDataGridView.NotifyCurrentCellDirty(true);

        base.OnValueChanged(eventargs);

    }

}

public class Form1 : Form

{

    private DataGridView dataGridView1 = new DataGridView();

    [STAThreadAttribute()]

    public static void Main()

    {

        Application.Run(new Form1());

    }

    public Form1()

    {

        this.dataGridView1.Dock = DockStyle.Fill;

        this.Controls.Add(this.dataGridView1);

        this.Load += new EventHandler(Form1_Load);

        this.Text = "DataGridView calendar column demo";

    }

    private void Form1_Load(object sender, EventArgs e)

    {

        CalendarColumn col = new CalendarColumn();

        this.dataGridView1.Columns.Add(col);

        this.dataGridView1.RowCount = ;

        foreach (DataGridViewRow row in this.dataGridView1.Rows)

        {

            row.Cells[].Value = DateTime.Now;

        }

    }

}