I have a DataGridview in which there is a DataTimePickerColumn, and it's DateTimePickerCell contain checkstate. How do I get the checkstate value after editing the checkstate?
Create a control inheriting from DateTimePicker and handle the DTN_DATETIMECHANGE notification. Then handle your DataGridView's EditingControlShowing event to add a handler for your DateTimePicker's new CheckedChanged event, or even you can create your own DataGridViewColumn and Cell type with DateTimePickerEx as EditingControl:
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
public class DateTimePickerEx : DateTimePicker
{
private bool _checked;
private const int WM_REFLECT = 0x2000;
public event CheckedChangedEventHandler CheckedChanged;
public delegate void CheckedChangedEventHandler(object sender, System.EventArgs e);
public DateTimePickerEx()
{
this._checked = this.Checked;
}
private void WmDateTimeChange(ref Message m)
{
NMDATETIMECHANGE nmdatetimechange = m.GetLParam(typeof(NMDATETIMECHANGE));
if (nmdatetimechange.dwFlags == GetDateTimeValues.GDT_NONE) {
if (this.ShowCheckBox && !this.Checked) {
this._checked = false;
if (CheckedChanged != null) {
CheckedChanged(this, EventArgs.Empty);
}
}
} else {
if (this.ShowCheckBox && this.Checked && !this._checked) {
this._checked = true;
if (CheckedChanged != null) {
CheckedChanged(this, EventArgs.Empty);
}
}
this.Value = SysTimeToDateTime(nmdatetimechange.st);
}
m.Result = IntPtr.Zero;
}
private bool WmReflectCommand(ref Message m)
{
if (m.HWnd == this.Handle) {
long code = NMHDR.FromMessage(m).code;
switch (code) {
case FWEx.Win32API.DateTimePickerNotifications.DTN_DATETIMECHANGE:
this.WmDateTimeChange(ref m);
return true;
}
return false;
}
}
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
protected override void WndProc(ref System.Windows.Forms.Message m)
{
if (m.Msg != 71 && m.Msg != 513) {
switch ((WindowsMessages)m.Msg) {
case WindowsMessages.WM_NOTIFY + WM_REFLECT:
if (!this.WmReflectCommand(ref m)) {
break;
}
return;
break;
}
}
base.WndProc(m);
}
private System.DateTime SysTimeToDateTime(SYSTEMTIME st)
{
return new System.DateTime(st.Year, st.Month, st.Day, st.Hour, st.Minute, st.Second);
}
/// <summary>
/// This structure contains information about a change that has taken place in a date and time picker (DTP) control.
/// This structure is used with the DTN_DATETIMECHANGE notification message.
/// </summary>
/// <remarks></remarks>
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct NMDATETIMECHANGE
{
/// <summary>
/// NMHDR structure that contains information about the notification message.
/// </summary>
public NMHDR nmhdr;
/// <summary>
/// Specifies if the control was set to no date status (for DTS_SHOWNONE only).
/// Also specifies whether the contents of the st member are valid and contain current time information.
/// </summary>
public GetDateTimeValues dwFlags;
/// <summary>
/// SYSTEMTIME structure that contains information about the current system date and time.
/// </summary>
public SYSTEMTIME st;
}
/// <summary>
/// This structure contains information about a message.
/// The pointer to this structure is specified as the lParam member of the WM_NOTIFY message.
/// </summary>
[StructLayout(LayoutKind.Sequential)]
public struct NMHDR
{
/// <summary>
/// Window handle to the control sending a message.
/// </summary>
public IntPtr hwndFrom;
/// <summary>
/// Identifier of the control sending a message.
/// </summary>
public IntPtr idFrom;
/// <summary>
/// Notification code. This member can be a control-specific notification code or it can be one of the common notification codes. The following values are supported if you include mouse support in your device platform:
/// - NM_RCLICK
/// - NM_RDBCLICK
/// </summary>
public int code;
public static NMHDR FromMessage(System.Windows.Forms.Message msg)
{
return (NMHDR)msg.GetLParam(typeof(NMHDR));
}
}
/// <summary>
/// Specifies a date and time, using individual members for the month, day, year, weekday, hour, minute, second, and millisecond.
/// The time is either in coordinated universal time (UTC) or local time, depending on the function that is being called.
/// </summary>
/// <remarks>
/// It is not recommended that you add and subtract values from the SYSTEMTIME structure to obtain relative times.
/// </remarks>
public struct SYSTEMTIME
{
/// <summary>
/// The year. The valid values for this member are 1601 through 30827.
/// </summary>
public short Year;
/// <summary>
/// The month.
/// </summary>
public short Month;
/// <summary>
/// The day of the week. Sunday = 0.
/// </summary>
public short DayOfWeek;
/// <summary>
/// The day of the month. The valid values for this member are 1 through 31.
/// </summary>
public short Day;
/// <summary>
/// The hour. The valid values for this member are 0 through 23.
/// </summary>
public short Hour;
/// <summary>
/// The minute. The valid values for this member are 0 through 59.
/// </summary>
public short Minute;
/// <summary>
/// The second. The valid values for this member are 0 through 59.
/// </summary>
public short Second;
/// <summary>
/// The millisecond. The valid values for this member are 0 through 999.
/// </summary>
public short Milliseconds;
}
public enum GetDateTimeValues
{
/// <summary>
/// Error.
/// </summary>
GDT_ERROR = -1,
/// <summary>
/// The control is not set to the no date status.
/// The st member contains the current date and time.
/// </summary>
GDT_VALID = 0,
/// <summary>
/// The control is set to no date status.
/// The no date status applies only to controls that are set to the DTS_SHOWNONE style.
/// </summary>
GDT_NONE = 1
}
public enum WindowsMessages
{
/// <summary>
///Sent by a common control to its parent window when an event has occurred or the control requires some information.
/// </summary>
WM_NOTIFY = 0x4e
}
public enum DateTimePickerNotifications
{
DTN_FIRST = -740,
DTN_LAST = -745,
DTN_FIRST2 = -753,
DTN_LAST2 = -799,
DTN_DATETIMECHANGE = DTN_FIRST2 - 6,
DTN_USERSTRING = DTN_FIRST2 - 5,
DTN_WMKEYDOWN = DTN_FIRST2 - 4,
DTN_FORMAT = DTN_FIRST2 - 3,
DTN_FORMATQUERY = DTN_FIRST2 - 2,
DTN_DROPDOWN = DTN_FIRST2 - 1,
DTN_CLOSEUP = DTN_FIRST2
}
}
Handle the DateTimePickerEx.CheckedChanged on DataGridView.EditingControlShowing:
private void dgv_EditingControlShowing(System.Object sender, System.Windows.Forms.DataGridViewEditingControlShowingEventArgs e)
{
switch (this.dgv.CurrentCellAddress.X) {
case 0: // your DateTimePickerEx column number
DateTimePickerEx dtp = e.Control as DateTimePickerEx;
if (dtp != null) {
dtp.CheckedChanged += (object sen, EventArgs ea) => {
//TODO: Add your code here
};
}
break;
}
}