pubnub removeListener 不会在 useEffect 上触发 return

Question

虽然打开单个聊天可以完美运行，但进入聊天，然后离开聊天屏幕并再次进入聊天会导致双重消息传递，尽管将监听器放置在 useEffect 中的 return 上，但它并没有被删除我什至在这个线程中尝试了解决方案：

希望大家能帮我找出问题所在。提前致谢！

 useEffect(() => {
   
    const listener = {
      message: (envelope: any) => {
        if (envelope) {
          const message = {
            channel: envelope.channel,
            message: {
              ...envelope.message,
            },
            uuid: envelope.publisher,
            timetoken: envelope.timetoken,
          }

          dispatch(setMessage(message))
// this log activates the same amount of times you entered and left the chat, because the listener isn't being removed
          console.log('Message listener activated!') 
        }

        //   setLastTimeToken(message.timetoken)
      },
    }

    pubnub.addListener(listener)
    pubnub.setUUID(employer._id)


    pubnub.fetchMessages(
      {
        channels: [ch],
        count: 100,
      },
      (status, response) => {
        if (response.channels[ch]) {
          dispatch(setMessages(response?.channels[ch]))
        } else {
          dispatch(setMessages([]))
        }
      },
    )
    pubnub.subscribe({ channels: [ch] })

    const usersInfo = channel.split('_')
    if (channel != employer._id && usersInfo[1] !== 'job') {
      const deeberId = usersInfo[0]
      getCandidateById(deeberId).then(res => {
        dispatch(setSelectedChatCandidate(res))
      })
    }
    renderDisplayName()

    return () => {
      pubnub.removeListener(listener) 

      pubnub.unsubscribeAll()
    }

  }, [])

Answer 1

升级 PubNub JS SDK 修复了导致多次回调触发的问题。 https://www.pubnub.com/docs/sdks/javascript/changelog#uv4342u

pubnub removeListener 不会在 useEffect 上触发 return

pubnub removeListener doesn't trigger on useEffect return

javascript

typescript

react-native

pubnub