C# 消息响应的一些例子

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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);
        }