//禁止通過拖動，雙擊標題欄改變窗體大小。
  public const int WM_NCLBUTTONDBLCLK = 0xA3;
  const int WM_NCLBUTTONDOWN = 0x00A1;
  const int HTCAPTION = 2;
  protected override void WndProc(ref Message m)
  {
    if (m.Msg == WM_NCLBUTTONDOWN && m.WParam.ToInt32() == HTCAPTION)
      return;
    if (m.Msg == WM_NCLBUTTONDBLCLK)
      return;

      base.WndProc(ref m)·}
    }
   }