我刚刚在我的react native和nodejs项目中完成了套接字的设置，但当消息发送时，我的平面列表仍然没有立即更新，我需要刷新应用程序才能更新。
我以为通过使用套接字，这将工作，但它仍然是不工作的。每当我的用户打开聊天，我得到例如。用户：1已加入控制台中的会话1，这表明套接字正在工作。
客户端

function ChatScreen({route,navigation}) {
const message = route.params.message;

const [messages, setMessages] = useState(message.Messages);
const [text, setText] = useState('');
const [socket, setSocket] = useState(null);
const { user } = useAuth();

const index = route.params.index;
const updateView = route.params.updateView;

useEffect(() => {
const newsocket =io.connect(socketURL)
setMessages(messages);
newsocket.on('connect', msg => {
    console.log(`user: ${user.id} has joined conversation ${message.id}`)
    setMessages(messages=>messages.concat(msg))
    setSocket(newsocket)
 });
 return()=>newsocket.close;
 }, []);

const onSend = (ConversationId,senderId,receiverId,message) => {

messagesApi.sendMessage({ConversationId,senderId,receiverId,message});
setText("")

const to = (user.id===route.params.message.user1? 
route.params.message.user2:route.params.message.user1)

socket.emit('message', { to: to, from: user.id, message, ConversationId });
};

const updateText=(text)=>{
setText(text);
}

return (
    <FlatList
    inverted
    data={message.Messages}
    keyExtractor={(message) => message.id.toString()}
    renderItem={({item,index})=>(
        <>
        <Text>
         {moment(item.createdAt).fromNow()}
         </Text>
        <MessageBubble
        text={item.message}
        mine={item.senderId !== user.id}
        />
         </>
    )}      
    />
    <View style={styles.messageBoxContainer}>
        <TextInput 
        onChangeText={updateText} 
        value={text} 
        />
        <TouchableOpacity 
          onPress={()=>{onSend(message.id,user.id,(user.id===message.user1? 
          message.user2:message.user1),text)}}>
        </TouchableOpacity>
    </View>
);
}

服务器端

const express = require("express");
const app = express();
const http = require("http");
const socket = require("socket.io")
const server=http.createServer(app);
const io =socket(server)

io.on('connection', (socket) => {
console.log("connected")
socket.on('message', (data) => {
console.log(data)
  socket.join(data.ConversationId);
  io.sockets.in(data.to).emit('send_message', { message: 
  data.message, to: data.to });
  });
  });

* 更新 *

客户端

const message = route.params.message;
  const [messages, setMessages] = useState([]);
  const [text, setText] = useState('');
  const [socket, setSocket] = useState(null);
  const { user } = useAuth();

  useEffect(() => {
  const newsocket =io.connect("http://192.168.1.103:9000")
  newsocket.on('connect', msg => {
  console.log(`user: ${user.id} has joined conversation 
  ${message.id}`)
  setSocket(newsocket)
  setMessages(message.Messages)
  });

  newsocket.on("send_message", (msg) => {
  console.log("this is the chat message:", msg);
  setMessages([ { ...message.Messages },...messages]);
  });

  return()=>newsocket.close;
  }, []);

  const onSend = (ConversationId,senderId,receiverId,message) => {
  console.log("sent")
messagesApi.sendMessage({ConversationId,senderId,receiverId,message});
setText("")
const to = (user.id===route.params.message.user1? 
route.params.message.user2:route.params.message.user1)
    socket.emit(
    'message', { to: to, from: user.id, message,ConversationId });
  };

 const updateText=(text)=>{
 setText(text);
 }

<FlatList
    inverted
    data={messages}
    keyExtractor={(message) => message.id.toString()}
    renderItem={({item,index})=>(
        <>
        <Text>
         {moment(item.createdAt).fromNow()}
         </Text>
        <MessageBubble
        text={item.message}
        mine={item.senderId !== user.id}
        />
         </>
    )}   
    bounces={false}  
    />
    <View style={styles.messageBoxContainer}>
        <TextInput 
        onChangeText={updateText} 
        value={text} 
        />
        <TouchableOpacity 
         onPress={()=>{
         onSend(
         message.id,
         user.id, 
         (user.id===message.user1?message.user2:message.user1),
         text
         )}}
         >
         <Text>Send</Text>
        </TouchableOpacity>
     </View>

服务器端

io.on('connection', (socket) => {
console.log("connected")
socket.on('message', (data) => {
console.log(data)
socket.emit('send_message', { message: data.message, receiverId: 
data.to,senderId:data.from,conversationId:data.ConversationId })
});
});

使用更新的代码，当我打开聊天我得到

user: 43 has joined conversation 4 ---- on client side console
connected ---- on server side console

使用更新的代码，当我发送消息时，我得到

this is the chat message: Object {
"conversationId": 25,
"message": "You",
"receiverId": 47,
"senderId": 43,
} --- in my client side console

{ to: 47, from: 43, message: 'You', ConversationId: 25 } ---- server 
side console

但是我得到一个错误

undefined is not an object (evaluating 'message.id.toString')

我想我的问题是我没有正确地发出消息id，因此我的平面列表不知道它。要获得消息id，我需要先将消息存储在db中

* 最新更新 *

客户端

const message = route.params.message;
  const [messages, setMessages] = useState([]);
  const [text, setText] = useState('');
  const [socket, setSocket] = useState(null);
  const { user } = useAuth();

  useEffect(() => {
  const newsocket =io.connect(socketURL)
  newsocket.on('connect', msg => {
  console.log(`user: ${user.id} has joined conversation 
  ${message.id}`)
  setSocket(newsocket)
  setMessages(message.Messages)
  });

  newsocket.on("send_message", (msg) => {
  console.log("this is the chat message:", msg);
  const data = [...messages]; 
  console.log(data)
  data.push(msg);
  setMessages(data); 
  });

  return(()=>newsocket.close());
  }, []);

  const onSend = (ConversationId,senderId,receiverId,message) => {
  console.log("sent")
messagesApi.sendMessage({ConversationId,senderId,receiverId,message});
setText("")
const to = (user.id===route.params.message.user1? 
route.params.message.user2:route.params.message.user1)
    socket.emit(
    'message', { to: to, from: user.id, message,ConversationId });
  };

 const updateText=(text)=>{
 setText(text);
 }

<FlatList
    inverted
    data={messages}
    keyExtractor={(item,index)=>index.toString()}
    renderItem={({item,index})=>(
        <>
        <Text>
         {moment(item.createdAt).fromNow()}
         </Text>
        <MessageBubble
        text={item.message}
        mine={item.senderId !== user.id}
        />
         </>
    )}   
    bounces={false}  
    />
    <View style={styles.messageBoxContainer}>
        <TextInput 
        onChangeText={updateText} 
        value={text} 
        />
        <TouchableOpacity 
         onPress={()=>{
         onSend(
         message.id,
         user.id, 
         (user.id===message.user1?message.user2:message.user1),
         text
         )}}
         >
         <Text>Send</Text>
        </TouchableOpacity>
     </View>

服务器端

io.on('connection', (socket) => {
console.log("connected")
socket.on('message', (data) => {
console.log(data)
socket.emit('send_message', { message: data.message, receiverId: 
data.to,senderId:data.from,conversationId:data.ConversationId })
});
});

现在使用新的更新代码，当我发送消息时，只有新消息被呈现给发送者，而没有以前的消息，接收者在聊天时没有收到任何东西。