TRTCCloud

  NSMutableDictionaryjsonDict = [[NSMutableDictionary alloc] init];
  [jsonDict setObject:@(102) forKey:@"roomId"];
  [jsonDict setObject:@"userB" forKey:@"userId"];
  NSData* jsonData = [NSJSONSerialization dataWithJSONObject:jsonDict options:NSJSONWritingPrettyPrinted error:nil];
  NSString* jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
  [trtc connectOtherRoom:jsonString];

  NSMutableDictionaryjsonDict = [[NSMutableDictionary alloc] init];
  [jsonDict setObject:@"102" forKey:@"strRoomId"];
  [jsonDict setObject:@"userB" forKey:@"userId"];
  NSData* jsonData = [NSJSONSerialization dataWithJSONObject:jsonDict options:NSJSONWritingPrettyPrinted error:nil];
  NSString* jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
  [trtc connectOtherRoom:jsonString];

    //In the small room that needs interaction, enter the room as an anchor and push audio and video streams
    TRTCCloud *mainCloud = [TRTCCloud sharedInstance];
    TRTCParams *mainParams = [[TRTCParams alloc] init];
    //Fill your params
    mainParams.role = TRTCRoleAnchor;
    [mainCloud enterRoom:mainParams appScene:TRTCAppSceneLIVE)];
    //...
    [mainCloud startLocalPreview:YES view:videoView];
    [mainCloud startLocalAudio:TRTCAudioQualityDefault];

    //In the large room that only needs to watch, enter the room as an audience and pull audio and video streams
    TRTCCloud *subCloud = [mainCloud createSubCloud];
    TRTCParams *subParams = [[TRTCParams alloc] init];
    //Fill your params
    subParams.role = TRTCRoleAudience;
    [subCloud enterRoom:subParams appScene:TRTCAppSceneLIVE)];
    //...
    [subCloud startRemoteView:userId streamType:TRTCVideoStreamTypeBig view:videoView];
    //...
    //Exit from new room and release it.
    [subCloud exitRoom];
    [mainCloud destroySubCloud:subCloud];