学步园

const int WM_NCHITTEST =
0x0084;

const int HTLEFT =
10;
const int HTRIGHT = 11;
const int HTTOP = 12;
const int HTTOPLEFT = 13;
const int HTTOPRIGHT = 14;
const int HTBOTTOM = 15;
const int HTBOTTOMLEFT =
0x10;
const int HTBOTTOMRIGHT =
17;

protected override void WndProc(ref
Message m)
{
   base.WndProc(ref m);
   switch (m.Msg)
    {
       case WM_NCHITTEST:
           
Point vPoint = new
Point((int)m.LParam
& 0xFFFF, 
                (int)m.LParam
>> 16
& 0xFFFF);
            vPoint
= PointToClient(vPoint);
           if (vPoint.X
<= 5)
               if (vPoint.Y
<= 5)
                    m.Result
= (IntPtr)HTTOPLEFT;
               else if (vPoint.Y
>= ClientSize.Height
- 5)
                    m.Result
= (IntPtr)HTBOTTOMLEFT;
               else m.Result
= (IntPtr)HTLEFT;
           else if (vPoint.X
>= ClientSize.Width
- 5)
               if (vPoint.Y
<= 5)
                    m.Result
= (IntPtr)HTTOPRIGHT;
               else if (vPoint.Y
>= ClientSize.Height
- 5)
                    m.Result
= (IntPtr)HTBOTTOMRIGHT;
               else m.Result
= (IntPtr)HTRIGHT;