c# - WinForms - 无边界 DateTimePicker

Question

我有一个看起来像这样的股票 winform datetimepicker...

我想让它看起来像这样......

WinForm TextBox 有一个无边框选项，我手动创建了一条水平线来产生无缝下划线 TextBox 的错觉，但是 DateTimePicker 好像没有borderless选项。

我可以做些什么来使 DateTimePicker 看起来像上面的示例，或者至少删除边框以便我可以手动放置下划线？

Answer 1

要实现控件的自定义外观，您必须覆盖 WndProc 方法，该方法处理此控件的所有窗口消息。

protected override void WndProc(ref Message m)
{
IntPtr hDC = GetWindowDC(m.HWnd);
Graphics gdc = Graphics.FromHdc(hDC);
switch (m.Msg)
{
case WM_NC_PAINT:
 SendMessage(this.Handle, WM_ERASEBKGND, hDC, 0);
 SendPrintClientMsg();
 SendMessage(this.Handle, WM_PAINT, IntPtr.Zero, 0);
 OverrideControlBorder(gdc);

 m.Result = (IntPtr)1; // indicate msg has been processed
 break;
case WM_PAINT: base.WndProc(ref m);
 OverrideControlBorder(gdc);
 OverrideDropDown(gdc);
 break;
  case  WM_NC_HITTEST:
 base.WndProc(ref m);
 if (DroppedDown)
  this.Invalidate(this.ClientRectangle, false);
 break;
default:
 base.WndProc(ref m);
 break;
}
ReleaseDC(m.HWnd, hDC);
gdc.Dispose();
}