无边窗体 鼠标进入窗体边界鼠标状态改变 进行调整窗体大小

        /// <summary>        /// 重写改变窗体大小        /// </summary>        /// <param name="m"></param>        protected override void WndProc(ref Message m)        {            const int WM_NCHITTEST = 0x0084;            int HTCLIENT = 1;            int HTLEFT = 10;            int HTRIGHT = 11;            int HTTOP = 12;            int HTTOPLEFT = 13;            int HTTOPRIGHT = 14;            int HTBOTTOM = 15;            int HTBOTTOMLEFT = 16;            int HTBOTTOMRIGHT = 17;            int offset = 3;            switch (m.Msg)            {                case WM_NCHITTEST:                    int px = Form.MousePosition.X - this.Left;                    int py = Form.MousePosition.Y - this.Top;                    int temp;                    if (px >= this.Width - offset)                    {                        if (py <= offset) temp = HTTOPRIGHT;                        else if (py >= this.Height - offset) temp = HTBOTTOMRIGHT;                        else temp = HTRIGHT;                    }                    else if (px <= offset)                    {                        if (py <= offset) temp = HTTOPLEFT;                        else if (py >= this.Height - offset) temp = HTBOTTOMLEFT;                        else temp = HTLEFT;                    }                    else                    {                        if (py <= offset) temp = HTTOP;                        else if (py >= this.Height - offset) temp = HTBOTTOM;                        else temp = HTCLIENT;                    }                    m.Result = (IntPtr)temp;                    break;                default:                    base.WndProc(ref m);                    break;            }        }