基本上，当被测试点位于窗体的客户区域时，您将覆盖WndProc方法将HTCAPTION返回到WM_NCHITTEST消息 – 这实际上是告诉Windows对待点击完全一样，就好像发生了表格的标题。

private const int WM_NCHITTEST = 0x84;
private const int HTCLIENT = 0x1;
private const int HTCAPTION = 0x2;

protected override void WndProc(ref Message m)
{
  switch(m.Msg)
  {
    case WM_NCHITTEST:
      base.WndProc(ref m);
      if ((int)m.Result == HTCLIENT)
      {
        m.Result = (IntPtr)HTCAPTION;
      }

      return;
  }

  base.WndProc(ref m);
}