C# to implement Winform borderless movement

This article describes the method of C# to implement borderless movement of Winform. Share it for your reference. The details are as follows:

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)
{
 switch ()
 {
  case 0x0084:
   (ref m);
   Point vPoint = new Point((int) &amp; 0xFFFF,
    (int) &gt;&gt; 16 &amp; 0xFFFF);
   vPoint = PointToClient(vPoint);
   if ( &lt;= 5)
    if ( &lt;= 5)
      = (IntPtr)HTTOPLEFT;
    else if ( &gt;=  - 5)
      = (IntPtr)HTBOTTOMLEFT;
    else  = (IntPtr)HTLEFT;
   else if ( &gt;=  - 5)
    if ( &lt;= 5)
      = (IntPtr)HTTOPRIGHT;
    else if ( &gt;=  - 5)
      = (IntPtr)HTBOTTOMRIGHT;
    else  = (IntPtr)HTRIGHT;
   else if ( &lt;= 5)
     = (IntPtr)HTTOP;
   else if ( &gt;=  - 5)
     = (IntPtr)HTBOTTOM;
   break;
  case 0x0201://The message pressed by the left mouse button    = 0x00A1;//Change the message to non-customer area and press the mouse    = ;//default value    = new IntPtr(2);//Put the mouse in the title bar   (ref m);
   break;
  default:
   (ref m);
   break;
 }
}

I hope this article will be helpful to everyone's C# programming.