角度 2 踩踏服务消耗

Question

我responseBody未定义，但我在msg_body中收到订阅响应。responseBody怎么了？

let stomp_subscription = this._stompService.subscribe('/topic/queue');
stomp_subscription.map((message: Message) => {
return message.body;
}).subscribe((msg_body: string) => {
console.log(`Received: ${msg_body}`);
this.responseBody = JSON.parse(msg_body);
console.log('RESPONSECODE' + this.responseBody.ResponseInfo.ResponseCode);
});

Answer 1

您正在使用来自可观察量的.map()运算符的return语句。因此，该值不会传递给针对可观察量的下一个.subscribe()调用。你能试试下面的代码吗

let stomp_subscription = this._stompService.subscribe('/topic/queue');
stomp_subscription.map((message: Message) => message.body )
.subscribe((msg_body: string) => {
console.log(`Received: ${msg_body}`);
this.responseBody = JSON.parse(msg_body);
console.log('RESPONSECODE' + this.responseBody.ResponseInfo.ResponseCode);
});