如何在 Foreach 循环中多次重新发出主题？

Question

我正在尝试订阅一个主题，该主题将在 forEach 中重新发出多次。但是我只订阅了一个，实际上是7次。

我试图延迟一些时间来执行带有setTimeOut 的"next()" 方法。但它不起作用。 Angular 客户端：6.2.9 节点：10.15.3 OS: win32 x64 RXJS：6.2.2 打字稿：2.7.2

private selectedVersion$: Subject<LeadTimeVersion> = new Subject<LeadTimeVersion>();
productLineId: string;
nodes: LeadTimeNode[] =[];
filterNodes: LeadTimeNode[];
versions: LeadTimeVersion[];
constructor( private leadTimeService: LeadTimeService) { }
ngOnInit() {

...

    let counter = 0;
    this.selectedVersion$.pipe(
      switchMap(v => this.leadTimeService.getLeadTimeVersionData(this.productLineId, v.id)),
      takeUntil(this.unsubscribe)
    ).subscribe(x => {
        this.nodes = mergeArray(this.nodes, x.nodes);
        counter++;
        if(counter === this.versions.length){
          this.filterTables('');
        }
    });

    this.leadTimeService.selectedLeadTimeWorkbench$.pipe(
      takeUntil(this.unsubscribe)
    ).subscribe(x => {
      this.productLineId = x.id;
      this.versions = x.workingVersions;

      this.versions.forEach(v => {

        this.selectedVersion$.next(v);
      })

    });

  }

Answer 1

将 switchMap 更改为 mergeMap。 switchMap 正在取消您之前的 API 响应并仅发出 API 的最新值。上面的答案有效，由@user2216584 回答。谢谢。

如何在 Foreach 循环中多次重新发出主题？

How to re-emit a Subject several times in a Foreach loop?

subject

observable

rxjs

angular