UEC++ From Basics to Advanced | M29-006: Exposing Start and Stop to Blueprint

Xiaogang writes the Blueprint Function Library that exposes the STT subsystem's Start, Stop, ForceStop, and IsWorking methods to Blueprint. The lesson demonstrates the standard pattern: obtaining the world context, retrieving the subsystem instance via UGameInstance, and calling the protected methods through a friend class declaration. The implementation includes proper error handling with CheckForce for null subsystems and descriptive warning logs. The lesson also covers Blueprint node categorization with keywords like 'Xingfei STT' for easy searching in the Blueprint editor, and the difference between latent function and pure function declarations. After compilation, the instructor tests the Blueprint integration in a Level Blueprint, successfully connecting to the iFlytek WebSocket server. The test shows the connection establishing and then timing out after 10-15 seconds since no audio data is sent yet, confirming the framework works end-to-end.