protected override void WndProc(ref Message m)

{

        const int WM_NCHITTEST = 0x84;

        const int HTCLIENT = 0x01;

        const int HTCAPTION = 0x02;

         if (m.Msg == WM_NCHITTEST)

        {

                this.DefWndProc(ref m);

                if (m.Result.ToInt32() == HTCLIENT)

                    m.Result = new IntPtr(HTCAPTION);

                else

                    base.WndProc(ref m);

        }

        else

        {

                base.WndProc(ref m);

        }

}

private const int WM_NCLBUTTONDOWN = 0x00A1;

private const int WM_NCHITTEST = 0x84;

private const int HT_CAPTION = 0x2;

private const int HT_CLIENT = 0x1;

private void pictureBox1_MouseDown(object sender, MouseEventArgs e)

{

    //this.Capture = false;

    pictureBox1.Capture = false;

    Message msg = Message.Create(Handle, WM_NCLBUTTONDOWN, (IntPtr)HT_CAPTION, IntPtr.Zero);

    WndProc(ref   msg);

} 

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;

   //在窗体的_MouseDown中加入如下代码:

如:

private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)

{

ReleaseCapture();

SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, );

}