this.router.events.subscribe((event) => {
  if (event instanceof NavigationStart) {
    this.showProgressBar = true
  } else if (event instanceof NavigationEnd) {
    this.showProgressBar = false
  }
  else if (event instanceof NavigationCancel) {
    this.showProgressBar = false
  }
})

您可以在任何事件路由状态下订阅

对于Angular 7，应该这样写:

this.router.events。订阅((事件:事件)=> {})

具体示例如下:

import { Component } from '@angular/core'; 
import { Router, Event, NavigationStart, NavigationEnd, NavigationError } from '@angular/router';

@Component({
    selector: 'app-root',
    template: `<router-outlet></router-outlet>`
})
export class AppComponent {

    constructor(private router: Router) {

        this.router.events.subscribe((event: Event) => {
            if (event instanceof NavigationStart) {
                // Show loading indicator
            }

            if (event instanceof NavigationEnd) {
                // Hide loading indicator
            }

            if (event instanceof NavigationError) {
                // Hide loading indicator

                // Present error to user
                console.log(event.error);
            }
        });

   }
}

我从RC 5开始这样做

this.router.events
  .map( event => event instanceof NavigationStart )
  .subscribe( () => {
    // TODO
  } );

如果您只是想检查路由/查询参数更改，如localhost:4200/users/1?编辑=1到localhost:4200/users/2?Edit =0你可以像下面这样使用可观察的参数。

import { ActivatedRoute, Params } from '@angular/router';
export class SomeClass implements OnInit {

paramFromRoute;

constructor(private route: ActivatedRoute) { }

ngOnInit() {
  this.paramFromRoute = this.route.snapshot.params['paramName']; // this one is required for getting it first time

  this.route.params.subscribe((params:Params)=>{
    this.paramFromRoute =  params['paramName'] // whenever route is changed, this function will triggered.
  });
  // for queryParams you can subscribe to this.route.queryParams
 }   
}

在Angular 8中，你应该这样做。router.events。订阅((事件:事件)=> {})

例子:

import { Component } from '@angular/core'; 
import { Router, Event } from '@angular/router';
import { NavigationStart, NavigationError, NavigationEnd } from '@angular/router';

@Component({
    selector: 'app-root',
    template: `<router-outlet></router-outlet>`
})
export class AppComponent {

    constructor(private router: Router) {
        //Router subscriber
        this.router.events.subscribe((event: Event) => {
            if (event instanceof NavigationStart) {
                //do something on start activity
            }

            if (event instanceof NavigationError) {
                // Handle error
                console.error(event.error);
            }

            if (event instanceof NavigationEnd) {
                //do something on end activity
            }
        });
   }
}

Angular 7，如果你想订阅路由器

import { Router, NavigationEnd } from '@angular/router';

import { filter } from 'rxjs/operators';

constructor(
  private router: Router
) {
  router.events.pipe(
    filter(event => event instanceof NavigationEnd)  
  ).subscribe((event: NavigationEnd) => {
    console.log(event.url);
  });
}