Example for invoking back to the main thread in MFC.
Some code, including direct UI updates, needs to run directly on the main application thread. When application code becomes increasingly parallelized, we need a simple, easy pattern to invoke back to the main thread which can be used directly across our applications.
The standard way to invoke in MFC would be to create a new WM_USER message and handler for every method which needs to be invoked. This works, but gets very clunky when creating a large number of invokes. We can solve this by having the invoker run one WM_USER message to use the operating system messaging to get back to the main thread, and then use a lambda function to make the function calls and variable management, vastly simplifying the code required to manage the invoke.