Angular Router Events: NavigationEnd — How to filter only the last event

问题

I want to extract only the last event entry of type NavigationEnd from router.events. But somehow I can't find a proper way to do this. Whatever I try the following code snipped is the only way to get access to these objects of interest.

let ne: any;

router.events.filter(e => e instanceof NavigationEnd)
   .forEach(e => {
      ne = e as NavigationEnd;                 
   });

console.log('target page: ', ne.urlAfterRedirects);

But do I really have to use .forEach() letting it run though all entries and using then the last entry? Isn't there a better way to handle the events as a kind of array and then say

ne = arrayOfEvents[arrayOfEvents.length-1]

?

I'm getting crazy about it but it seems that I can't see the wood for the trees...

回答1:

PS. There's a better way to filter using a 'typeguard', you then get the proper type without having to assert it again:

firstChildData$ = this.router.events.pipe(

            filter((e): e is NavigationEnd => e instanceof NavigationEnd), 

            map(e => { // e is now NavigationEnd }

This is actually necessary in strict mode.

回答2:

Okay, after reading through the posted articles above and rethinking what I really want to achieve I found out that my approach was definitely too complicated. Because actually I only need access to the currently called route. And so I started from scratch and came across this small but very effective solution:

this.router.events.subscribe(value => {
    console.log('current route: ', router.url.toString());
});

Thanks to all who shared a comment in oder to support me! It helped al lot as I was able to tie up loose ends.

来源：https://stackoverflow.com/questions/49722369/angular-router-events-navigationend-how-to-filter-only-the-last-event