C#窗体随意移动

　　　　　//全区域移动
        const int WM_NCLBUTTONDOWN = 0xA1;
        const int HT_CAPTION = 0x2;
        [DllImport("user32.dll")]
        static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
        protected override void OnMouseDown(MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                this.Capture = false;
                SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, );
            }
            else
            {
                this.Close(); // 右键可以退出窗体
            }
        }
　　　　　
　　　　　
　　　　　

　　　　　//标题区域移动
　　　　　[DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;

        public void ShapedForm_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, );
        }