Code highlighting produced by Actipro CodeHighlighter (freeware) const int HTLEFT = 10; const int HTRIGHT = 11; const int HTTOP = 12; const int HTTOPLEFT = 13; const int HTTOPRIGHT = 14; const int HTBOTTOM = 15; const int HTBOTTOMLEFT = 0x10; const int HTBOTTOMRIGHT = 17; protected override void WndProc(ref Message m) {     switch (m.Msg)     {         case 0x0084:             base.WndProc(ref m);             Point vPoint = new Point((int)m.LParam & 0xFFFF,                 (int)m.LParam >> 16 & 0xFFFF);             vPoint = PointToClient(vPoint);             if (vPoint.X <= 5)                 if (vPoint.Y <= 5)                     m.Result = (IntPtr)HTTOPLEFT;                 else if (vPoint.Y >= ClientSize.Height - 5)                     m.Result = (IntPtr)HTBOTTOMLEFT;                 else m.Result = (IntPtr)HTLEFT;             else if (vPoint.X >= ClientSize.Width - 5)                 if (vPoint.Y <= 5)                     m.Result = (IntPtr)HTTOPRIGHT;                 else if (vPoint.Y >= ClientSize.Height - 5)                     m.Result = (IntPtr)HTBOTTOMRIGHT;                 else m.Result = (IntPtr)HTRIGHT;             else if (vPoint.Y <= 5)                 m.Result = (IntPtr)HTTOP;             else if (vPoint.Y >= ClientSize.Height - 5)                 m.Result = (IntPtr)HTBOTTOM;             break;         case 0x0201://鼠标左键按下的消息             m.Msg = 0x00A1;//更改消息为非客户区按下鼠标             m.LParam = IntPtr.Zero;//默认值             m.WParam = new IntPtr(2);//鼠标放在标题栏内             base.WndProc(ref m);             break;         default:             base.WndProc(ref m);             break;     } }