我从RC 5开始这样做

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

以上大多数解决方案是正确的，但我面临的问题是这个发射多次'导航发射'事件。当我改变任何路由时，此事件被触发。所以hear是Angular 6的完整解决方案。

import { Subscription } from 'rxjs/Subscription';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/filter';    

export class FooComponent implements OnInit, OnDestroy {
   private _routerSub = Subscription.EMPTY;
   constructor(private router: Router){}

   ngOnInit(){
     this._routerSub = this.router.events
      .filter(event => event instanceof NavigationEnd)
      .subscribe((value) => {
         //do something with the value
     });
  }

  ngOnDestroy(){
   this._routerSub.unsubscribe();
  }
} 

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
            }
        });
   }
}

@Ludohen的回答很好，但如果你不想使用instanceof，请使用下面的方法

this.router.events.subscribe(event => {
  if(event.constructor.name === "NavigationStart") {
    // do something...
  }
});

通过这种方式，您可以检查当前事件名称作为字符串，如果事件发生，您可以执行您计划的函数要执行的操作。

路由器3.0.0-beta。2应该是

this.router.events.subscribe(path => {
  console.log('path = ', path);
});

我是这么说的:

class ClassName {
  constructor(private router: Router) {
    router.events.subscribe((value) => {
        // see this 
        console.log(value instanceof NavigationEnd) 
    });
  }
}