CPSUI Message Handler

A CPSUI message handler is a callback function that is defined using the _CPSUICALLBACK function type. This type of page event callback is recommended if you are using CPSUI-supplied pages and templates.

When a user interacts with a property sheet page and causes an event to occur, CPSUI intercepts the event and calls the _CPSUICALLBACK-typed function, supplying a CPSUICBPARAM structure that describes the reason the callback function is being called.

The callback function must handle the event, and then return a status value to CPSUI that indicates if the page needs to be redisplayed or reinitialized.