我正在尝试在我的代码中使用 combineLatest。代码如下：

this.selectedIcon$ = this.iconForm.get('selectedIcon').valueChanges
   .pipe(takeUntil(this.unsubscribe$))
   .pipe(startWith(''))
   .pipe(tap((value) => { 
    //This not being called / set,every time the values changes.
    this.searchIcon = value;
    }));
 
   this.selectedColour$ = this.iconForm.get('selectedColour').valueChanges
   .pipe(takeUntil(this.unsubscribe$))
   .pipe(startWith(''))
   .pipe(tap((value) => { 
       this.selectedColour = value; 
    }));
 
   let data$ = this.menuNavigationProvider.iconCssData
    .pipe(takeUntil(this.unsubscribe$));
 
 combineLatest([data$,this.selectedIcon$]).subscribe(([data,icon]) => {
     console.log(data+ ' - ' + icon);
 });

当 'selectedIcon' 值改变时，订阅不起作用。谁能纠正我我在这里做的错误？在上面的代码中，我希望每次更改值时都设置 this.searchIcon = value。

谢谢