void SetRedraw( BOOL bRedraw = TRUE );
bRedraw
Specifies the state of the redraw flag. If this parameter is TRUE, the redraw flag is set; if FALSE, the flag is cleared.
An application calls SetRedraw to allow changes to be redrawn, or to prevent changes from being redrawn.
This member function sets or clears the redraw flag. While the redraw flag is cleared, the contents will not be updated after each change, and will not be repainted until the redraw flag is set. For example, an application that needs to add several items to a list box can clear the redraw flag, add the items, then set the redraw flag. Finally, the application can call the Invalidate or InvalidateRect member function to cause the list box to be repainted.
WM_SETREDRAW