This method updates the specified rectangle or region in the specified window’s client area.
| Header file: | Afxwin.h | 
| Platforms: | H/PC 2.0, Palm-size PC, H/PC Pro | 
| Windows CE versions: | 1.0 and later | 
| Complete documentation: | Visual C++ documentation | 
BOOL RedrawWindow( LPCRECT lpRectUpdate = NULL, CRgn* prgnUpdate = NULL, UINT flags = RDW_INVALIDATE | RDW_UPDATENOW | RDW_ERASE );