I want to get my_user_ID after join meeting. I see there is a getMyUserID() function (InMeetingService (Zoom.us SDK API Document)) may I know how do we call that function? Is there any callback for meetingService.joinMeetingWithParams(mContext, params, options); so that I can call getMyUserID() after join successfully?
With regards to callbacks, the joinMeetingWithParams() method returns a constant from MeetingError (Zoom.us SDK API Document) - From here you should be able to determine if it was successful or not.
You can also use the MeetingEvent class to see whether or not a user joined successfully.