DateTimePicker control in ContextMenuStrip

Question

我使用ToolStripControlHost在ContextMenuStrip中添加了一个DateTimePicker。我使用下面的代码。

DateTimePicker startDate = new DateTimePicker();
(cms.Items["mnuStartDate"] as ToolStripMenuItem).DropDownItems.Add(new ToolStripControlHost(startDate));

选择日期是有效的，但当我点击箭头去前一个月或下一个月，或者如果我点击月份，工具条正在关闭。有什么解决办法吗?谢谢。

注意:我显示cms(ContextMenuStrip)时右键单击一个控件。

Answer 1

看起来ToolStrip行为在选择项时关闭。所以我只使用CalendarMonth Control作为替代。链接

Answer 2

这似乎与Application.EnableVisualStyles();有关，当未启用时，菜单不会意外关闭。

当启用时，为了防止关闭，检测CalendarMonth菜单当前是否可见，以及鼠标是否被单击。

public class DatePicker : DateTimePicker {
private const int DtmFirst = 0x1000;
private const int DtmGetmonthcal = (DtmFirst + 8);
private bool isDroppedDown = false;
private IntPtr hwndCalendarWindow = IntPtr.Zero;
protected override void OnDropDown(EventArgs e) {
isDroppedDown = true;
hwndCalendarWindow = SendMessage(Handle, DtmGetmonthcal, 0, 0);
base.OnDropDown(e);
}
protected override void OnCloseUp(EventArgs eventargs) {
isDroppedDown = false;
base.OnCloseUp(eventargs);
}
public bool CalendarMonthClicked(Point pt) {
if (!isDroppedDown)
return false;
RECT r = new RECT();
GetWindowRect(hwndCalendarWindow, out r);
return pt.X >= r.Left && pt.X <= r.Right && pt.Y >= r.Top && pt.Y <= r.Bottom;
}
[DllImport("user32.dll")]
private static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);
[DllImport("User32.dll")]
private static extern IntPtr SendMessage(IntPtr h, int msg, int param, int data);
[StructLayout(LayoutKind.Sequential)]
private struct RECT {
public int Left, Top, Right, Bottom;
}
}
static class Program {
//[DllImport("uxtheme.dll", ExactSpelling = true, CharSet = CharSet.Unicode)]
//public extern static Int32 SetWindowTheme(IntPtr hWnd, String textSubAppName, String textSubIdList);
[STAThread]
static void Main() {
Application.EnableVisualStyles(); // if you disable visual styles then the menu won't close
DatePicker dpStart = new DatePicker();
dpStart.MinimumSize = new Size(100, 50);
Form ff = new Form();
ContextMenuStrip cms = new ContextMenuStrip();
ToolStripMenuItem menu = new ToolStripMenuItem("Menu");
menu.DropDown.Closing += (o, e) => {
e.Cancel = (e.CloseReason == ToolStripDropDownCloseReason.AppClicked && dpStart.CalendarMonthClicked(Cursor.Position));
};
// sub-menu doesn't close properly, probably related to the ToolStripControlHost
cms.Opening += delegate {
menu.DropDown.Close(ToolStripDropDownCloseReason.CloseCalled);
};
cms.Closed += delegate {
menu.DropDown.Close(ToolStripDropDownCloseReason.CloseCalled);
};
ff.ContextMenuStrip = cms;
cms.Items.Add(menu);
ToolStripControlHost item = new ToolStripControlHost(dpStart) { AutoSize = true };
menu.DropDownItems.Add(item);
Application.Run(ff);
}
}