ZForge.Controls.HeaderPanel.WndProc C# (CSharp) Method

        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
                case WM_NCCALCSIZE:
                    WmNCCalcSize(ref m);
                    break;
                case WM_NCPAINT:
                    IntPtr hDC = HeaderPanelNativeMethods.GetWindowDC(m.HWnd);
                    if (hDC != IntPtr.Zero)
                    {
                        using (Graphics canvas = Graphics.FromHdc(hDC))
                        {
                            PaintNonClientArea(canvas);
                        }
                        HeaderPanelNativeMethods.ReleaseDC(m.HWnd, hDC);
                    }
                    m.Result = IntPtr.Zero;
                    break;
            }
            base.WndProc(ref m);
        }