Angular:如何知道HttpClient中的请求是否已被取消

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要知道请求是否已完成，请执行if (httpEvent instanceof HttpResponse).同样，如何知道HttpInterceptor中的请求是否被取消?下面是我的intercept函数.

To know if a request has completed, I do if (httpEvent instanceof HttpResponse). Likewise, how to know if a request is cancelled in HttpInterceptor? Below is my intercept function.

intercept(httpRequest: HttpRequest<any>, httpHandler: HttpHandler): Observable<HttpEvent<any>> { this.requestsPending++; if (this.typeAheads.includes(httpRequest.url.split('/').pop())) this.slimLoadingBarService.start(); else this.flsLoaderService.start(); return httpHandler.handle(httpRequest) .do((httpEvent: HttpEvent<any>) => { if (httpEvent instanceof HttpResponse) { // decrementing counter on each request return this.requestsPending--; if (this.typeAheads.includes(httpEvent.url.split('/').pop())) { if (this.requestsPending === 0) this.slimLoadingBarServiceplete(); } else { if (this.requestsPending === 0) this.flsLoaderService.stop(); } } }, () => { this.slimLoadingBarServiceplete(); // reset counter on error this.requestsPending = 0; this.flsLoaderService.stop(); }); }

推荐答案

我也遇到了这个问题，这是我最近遇到的一个解决方案:

I have also had this problem and that's a solution to which I've came recently:

要知道请求是否已取消，可以使用finally运算符，例如:

to know if a request was cancelled you can use finally operator, heres example:

let cancelled = true; return next.handle(request).do( undefined, () => { // error cancelled = false; }, () => { // completed cancelled = false; }, ).finally( () => { if (cancelled) { // do things } }, );