Android套接字io获取在线用户

Question

我正在开发一个Android私人聊天应用程序。在这个应用程序中，我想查看在线用户或检查用户是否在线。我有参考。

emit("login",userid); 

用于获取在线用户。所以我用

public class OnlineActivity extends AppCompatActivity { 
    private Socket mSocket; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_online); 

     ChatApplication app = (ChatApplication) getApplication(); 
     mSocket = app.getSocket(); 

     JSONObject user = new JSONObject(); 
     try { 
      user.put("userId", "abc"); 
     } catch (JSONException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     mSocket.emit("login",user); 

     Log.d("LOG", String.valueOf(mSocket.emit("login",user))); 
     Log.d("LOG", String.valueOf(user)); 
    } 
} 

其中abc是用户ID，但它不显示任何结果。请帮帮我。

Answer 1

答案在How to check a user online or not in socket io and android chat application

socket.on('isActive', function (user) { 
const userId = user.userId; 
const user = usernames[userId]; 
const socketId = socket.id; 
let response; 
if(user) { 
    // User is active 
    response = {isActive: true}; 
} else { 
    // User is not active 
    response = {isActive: false}; 
} 
const responseSocket = io.sockets.connected[socketId]; 
if(responseSocket) { 
    responseSocket.emit('onIsActive', response); 
} 
}); 

所示