private void panel3_MouseEnter(object sender, EventArgs e) //滑鼠經過
        {
            panel3.BackColor = Color.FromArgb(128, 128, 255);
        }


        private void panel3_MouseLeave(object sender, EventArgs e) //滑鼠移出
        {
            panel3.BackColor = Color.FromArgb(192, 192, 255);
        }
 

using System.Runtime.InteropServices;


 [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; 


   private void panel1_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }