Call this method to assign a response processing callback function.
PFNATLSTATUSCALLBACK SetReadStatusCallback( PFNATLSTATUSCALLBACK pfn, DWORD_PTR dwData ) throw( );
A pointer to the response processing callback function, as defined by the PFNATLSTATUSCALLBACK typedef.
Context data that is to be passed to the callback function each time it is invoked.
If a read status callback is installed, the CAtlHttpClientT class will call the provided function whenever new response data arrives. This mechanism allows for the display of partial responses (such as images that are displayed incrementally) and progress bars.