问题描述
我使用 ToolStripControlHost 在 ContextMenuStrip 中添加了一个 DateTimePicker。我正在使用以下代码。
DateTimePicker startDate = new DateTimePicker();
(cms.Items["mnuStartDate"] as ToolStripMenuItem).DropDownItems.Add(new ToolStripControlHost(startDate));
选择日期有效,但是当我单击箭头转到上个月或下个月时,或者如果我单击月份,则 ToolStrip 正在关闭。这里有什么解决方法吗?谢谢。
注意:我在控件上单击鼠标右键时显示 cms(ContextMenuStrip)。
解决方法
看起来 ToolStrip 行为在选择项目时关闭。所以我突出使用 CalendarMonth Control 作为替代。链接here
,似乎与Application.EnableVisualStyles();
有关,未启用时,菜单不会意外关闭。
启用后,为防止关闭,请检测 CalendarMonth
菜单当前是否可见,以及是否点击了鼠标。
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);
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);
}
}