Enables or disables redraw optimization for MDI child windows.
The default value is TRUE.
Set this flag to FALSE if you want to optimize redrawing of MDI children. In this case the framework will call SetRedraw (FALSE) for the main frame when the application is changing the active tab.
This flag can cause unwanted effects (such as background applications that become visible). Therefore we recommend that you change the default only if you experience noticeable flickering during MDI tab activation.