reactjs - 无法在本机反应中使用 Sockjs 添加聊天消息

Question

我在我的 Flatlist 中添加聊天消息时遇到问题，因为我无法调用stompClient.subscribe ()中的任何函数 我的代码如下：

     dummy='dummyurl';
sock = new SockJS(this.dummy);

componentDidMount() {
var that = this;
this.sock.onConnect =(e) =>{
 console.log("connected")
}
this.sock.onopen = function() {
 console.log('open');
 var dummy2='dummyurl';
  var sock2 = new SockJS(dummy2);
   let stompClient = Stomp.over(sock2);
        stompClient.heartbeat.outgoing = 20000;
        stompClient.heartbeat.incoming = 0;
        stompClient.connect({}, (frame) => {
      stompClient.subscribe('xyz/getChat', (messageOutput) =>{
         var mymessage =JSON.parse(messageOutput.body).message;
         this.state = {
           incomingchatMessage: "",
           chatMessages:[]
         }
         that.setState({incomingchatMessage:mymessage})  //getting issue setState not found
         console.log(this.state)
      });
      });
};
this.sock.onmessage =(e) =>{
console.log('message', e);
alert("on message calledj")
};
this.sock.onmessage = evt => {
console.log("erve");
}

}

在这段代码中，我能够在 new_message 变量中获取网络消息，但无法在此处更新状态值。这种情况的任何解决方案。