Datetimepicker 文本值更改但值未给出预期值

Question

我创建了一个 class 更改压光机的外观。 class 基于这些先前的 Whosebug 问题：

来源 1：Setting calendar size when overriding DateTimePicker to add week numbers

来源 2：Increase Font Size of DateTimePicker Calender in Win7 Aero Theme

这是class:

class DateTimePickerImpl : DateTimePicker
{
    private const int McmFirst = 0x1000;
    private const int McmGetminreqrect = (McmFirst + 9);
    private const int McsWeeknumbers = 0x4;
    private const int DtmFirst = 0x1000;
    private const int DtmGetmonthcal = (DtmFirst + 8);

    [DllImport("User32.dll")]
    private static extern int GetWindowLong(IntPtr handleToWindow, int offsetToValueToGet);
    [DllImport("User32.dll")]
    private static extern int SetWindowLong(IntPtr h, int index, int value);
    [DllImport("uxtheme.dll")]
    private static extern int SetWindowTheme(IntPtr hWnd, string appname, string idlist);
    [DllImport("User32.dll")]
    private static extern IntPtr SendMessage(IntPtr h, int msg, int param, int data);
    [DllImport("User32.dll")]
    private static extern IntPtr GetParent(IntPtr h);
    [DllImport("User32.dll")]
    private static extern int SendMessage(IntPtr h, int msg, int param, ref Rectangle data);
    [DllImport("User32.dll")]
    private static extern int MoveWindow(IntPtr h, int x, int y, int width, int height, bool repaint);

    protected override void OnDropDown(EventArgs e)
    {
        CalendarFont = new Font("Microsoft Sans Serif", 20F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
        const int offsetToGetWindowsStyles = (-16);

        IntPtr pointerToCalenderWindow = SendMessage(Handle, DtmGetmonthcal, 0, 0);
        SetWindowTheme(pointerToCalenderWindow, "", "");
        int styleForWindow = GetWindowLong(pointerToCalenderWindow, offsetToGetWindowsStyles);

        styleForWindow = styleForWindow | McsWeeknumbers;

        Rectangle rect = new Rectangle();
        SendMessage(pointerToCalenderWindow, McmGetminreqrect, 0, ref rect);

        rect.Width = rect.Width + 30;
        rect.Height = rect.Height + 10;

        SetWindowLong(pointerToCalenderWindow, offsetToGetWindowsStyles, styleForWindow);

        MoveWindow(pointerToCalenderWindow, 0, 0, rect.Width, rect.Height, true);

        IntPtr parentWindow = GetParent(pointerToCalenderWindow);
        MoveWindow(parentWindow, 0, 0, rect.Width, rect.Height, true);

        base.OnDropDown(e);
    }
}

实施此 class 后，日期时间选择器的可见文本将更改为您选择的任何内容。但是当使用 dateTimePickerImpl.Value 时，它总是 returns 它开始的时间（加载 datetimpicker 的时间）。我已经通过向 ValueChanged 事件添加一个方法发现该事件永远不会发生。我在网上发现了一些类似的问题，但这些都是通过将 datetimepicker 的 checked 属性设置为 true 来解决的。在我的例子中 checked 属性已经是真的。

我做了什么破坏了日期时间选择器？

Answer 1

我不得不手动创建日期时间选择器，而不是将它从工具箱拖到设计器中。

DateTimePickerImpl dtp = new DateTimePickerImpl();
dtp.Location = new Point(3, 254);
dtp.Name = "dtp";
dtp.Size = new Size(271, 26);
dtp.TabIndex = 25;
panel1.Controls.Add(dtp);

Datetimepicker 文本值更改但值未给出预期值

Datetimepicker text value changes but value doesn't give the expected value

.net

c#

datetimepicker

winforms