Provides access to the asynchronous function API, allowing the developer to control the background threads.
Beginning in Excel 2010, functions can be marked as "Asynchronous". The CXlAsyncManager class manages the execution of queued asynchronous worksheet functions. These functions use a background (worker) thread to run their implementations and inform the Excel calculation tree that they are complete by calling the xlAsyncReturn SDK call-back. See Queued functions in the User Guide for more information.
The object should not be created directly. A single instance of the class is created on demand by the method CXllApp::GetXlAsyncManager().
Once you have retrieved a pointer to the CXlAsyncManager instance, you can set the maximum number of threads used by the asynchronous function mechanism with the SetMaxThreads() method. During operation, you can use Stop() and Start() to control the worker threads.