c# 關閉 窗口最小化

protected override void WndProc(ref System.Windows.Forms.Message m)         {             const int wm_syscommand = 0x0112;             const int sc_close = 0xF060;             if (m.Msg == wm_syscommand && (int)m.WParam == sc_close)             {                 this.WindowState = FormWindowState.Minimized;                 return;             }             base.WndProc(ref m);         }