Prepares or unprepares an event asynchronously. The Events are identified by string (refer to General Information for a discussion on using strings and IDs). Before invoking PrepareEvent(), use LoadBank() to explicitly load the SoundBank(s) that contain the Events and structures. When a request is posted to the Bank Manager consumer thread, it will resolve all dependencies needed to successfully post the specified Events and load the required loose media files.
The function returns immediately. Use a callback to be notified when the request has finished being processed.