RongIM.init(this, 'AppKey', false);
RongIM.connect("Token", new RongIMClient.ConnectCallback() {
  @Override
  public void onTokenIncorrect() { }

  @Override
  public void onSuccess(String userId) { }

  @Override
  public void onError(RongIMClient.ErrorCode errorCode) { }
});

[[RCIM sharedRCIM] initWithAppKey:@"AppKey"];

[[RCIM sharedRCIM] connectWithToken:@"Token" success:^(NSString *userId) {

} error:^(RCConnectErrorCode status) {

} tokenIncorrect:^{

}];
                
              

RongIMLib.RongIMClient.init('AppKey');

RongIMClient.connect('Token', {
  onSuccess: function(userId) { },

  onTokenIncorrect: function() { },

  onError: function(errorCode) { }
});
                
              

//Initialization
RongIMClient.init(RongAppKey);
//connection
RongIMClient.connect(RongIMToken, (int code, String userId) {
  print('connect result ' + code.toString());
  if (code == 0) {
    print("connect success userId" + userId);
  } else if(code == 31004) {
    /* 
      the token is invalid, 
      you need to re-obtain the token from the APP service and connect
    */
  }
});

RongRTCEngine.getInstance().joinRoom(
'RoomId', new JoinRoomUICallBack() {
  @Override
  protected void onUiSuccess(RongRTCRoomrongRTCRoom) { }

  @Override 
  protected void onUiFailed(RTCErrorCode rtcErrorCode) { }
});

[[RongRTCEngine sharedEngine]
joinRoom:@"RoomID"
completion:^(RongRTCRoom * _Nullable
room, RongRTCCode code) {
}];

let room = new Room({
  id: 'RoomId',
  joined: function(user){ },
  left: function(user){ }
});
let user = {
  id: 'userId'
};
room.join(user).then(() => { }, error => { });

RongCloudImPlugin.init(RongAppKey);
int rc = await RongCloudImPlugin.connect(IMToken);
print("connecting im " + rc.toString());
RongRTCEngine.joinRTCRoom(this.roomId,(int code) {});
RongRTCEngine.startCapture();