Hi!

I am trying to make a custom size title-bar in the non-client area of the
form. I've tried hooking to the NCCALCSIZE message with this code:

case (int)Native.NativeMethods.WindowMessages.WM_NCCALCSIZE:
                   if (m.WParam == IntPtr.Zero)
                   {
                       // get the NCCALCSIZE parameters
                       NativeMethods.NCCALCSIZE_PARAMS csp;

                       // Marshal them from the pointer
                       csp =
(NativeMethods.NCCALCSIZE_PARAMS)Marshal.PtrToStructure(m.LParam,
                           typeof(NativeMethods.NCCALCSIZE_PARAMS));

                       // Resize the client area to make more room above
                       csp.rectBeforeMove.top-= csp.rectBeforeMove.top/ 2;
                       
                       Marshal.StructureToPtr(csp, m.LParam, false);
                   }
                   else
                   {
                       base.WndProc(ref m);
                   }
                   return;

However, it just says that I am trying to read or write into a protected
memory. If i modify any other value, i.e. right, left or bottom of the same
rectangle, it works OK yet there are no changes. I also tried changing the
other two rectangles, but the result is never what I need.

I would really appriciate any suggestions on this topic.