How to write an out-of-process MS UI Automation client

Question

Much of the documentation I've read regarding UIA lauds its ability to be used out-of-process with significant performance improvements over out-of-process MSAA clients, but I can't seem to drum up any documentation describing how to actually write your client in this way.

I'm guessing it has to do with how you call CoCreateInstance, and so the first thing I tried was changing the argument from CLSCTX_INPROC_SERVER to CLSCTX_LOCAL_SERVER, which resulted in a "class not registered" error, which I have yet to find the cause of. Are there additional steps required on my part?

Thanks for any assistance.

Answer 1

You do this using IUIAutomationCacheRequest , BuildUpdatedCache and GetCachedPattern along with the various CachedXXXX properties. Requesting the current patterns/properties requires a round trip per request; building the cache allows you to get all the patterns & properties you need in a single request.