为那些使用Angular9+的人更新了答案，通过使用@angular/ Router提供的路由器API并监听路由变化

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

    @Component({
      selector: 'my-app',
      templateUrl: './app.component.html',
      styleUrls: [ './app.component.css' ]
    })
    export class AppComponent  {
      
      name = 'Get Current Url Route Demo';
      currentRoute: string;
     routeSubscription: subscription;
    
      constructor(private router: Router){
        console.log(router.url);
        
        this.routeSubscription = router.events.filter(event => event instanceof NavigationEnd)
              .subscribe(event => 
               {
                  this.currentRoute = event.url;          
                  console.log(event);
               });
        }
    }

下面的方法可以帮你解决棘手的问题。

// in constructor of your app.ts with router and auth services injected
router.subscribe(path => {
    if (!authService.isAuthorised(path)) //whatever your auth service needs
        router.navigate(['/Login']);
    });

不幸的是，这在路由过程中比我想要的晚些时候重定向。在重定向之前调用原始目标组件的onActivate()。

你可以在目标组件上使用@CanActivate装饰器，但这是a)不集中的，b)不能从注入的服务中受益。

如果有人能提出一种更好的方法，在路由提交之前对其进行集中授权，那就太好了。我相信一定有更好的办法。

这是我当前的代码(我如何改变它来监听路由变化?):

import {Component, View, bootstrap, bind, provide} from 'angular2/angular2';
import {ROUTER_BINDINGS, RouterOutlet, RouteConfig, RouterLink, ROUTER_PROVIDERS, APP_BASE_HREF} from 'angular2/router';    
import {Location, LocationStrategy, HashLocationStrategy} from 'angular2/router';

import { Todo } from './components/todo/todo';
import { About } from './components/about/about';

@Component({
    selector: 'app'
})

@View({
    template: `
        <div class="container">
            <nav>
                <ul>
                    <li><a [router-link]="['/Home']">Todo</a></li>
                    <li><a [router-link]="['/About']">About</a></li>
                </ul>
            </nav>
            <router-outlet></router-outlet>
        </div>
    `,
    directives: [RouterOutlet, RouterLink]
})

@RouteConfig([
    { path: '/', redirectTo: '/home' },
    { path: '/home', component: Todo, as: 'Home' },
    { path: '/about', component: About, as: 'About' }
])

class AppComponent {    
    constructor(location: Location){
        location.go('/');
    }    
}    
bootstrap(AppComponent, [ROUTER_PROVIDERS, provide(APP_BASE_HREF, {useValue: '/'})]);

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
 }   
}

更清晰的方法是继承RouteAware并实现onNavigationEnd()方法。

它是一个名为@bespunky/angular-zen的库的一部分。

NPM install @bespunky/angular-zen 让你的AppComponent扩展RouteAware并添加一个onNavigationEnd()方法。

import { Component     } from '@angular/core';
import { NavigationEnd } from '@angular/router';
import { RouteAware    } from '@bespunky/angular-zen/router-x';

@Component({
    selector   : 'app-root',
    templateUrl: './app.component.html',
    styleUrls  : ['./app.component.css']
})
export class AppComponent extends RouteAware
{    
    protected onNavigationEnd(event: NavigationEnd): void
    {
        // Handle authentication...
    }
}

RouteAware还有其他好处，比如: ✨任何路由器事件都可以有处理程序方法(Angular支持的路由器事件)。 ✨使用这个。路由器访问路由器 ✨使用这个。访问激活路由的路由 ✨使用this.componentBus访问RouterOutletComponentBus服务

在Angular 10中，你可以像下面这样做……

    import { Component, OnInit } from '@angular/core';
    import { Router, NavigationEnd } from '@angular/router';
    import { filter } from 'rxjs/operators';
    
    @Component({
      selector: 'app-my-class',
      templateUrl: './my-class.component.html',
      styleUrls: ['./my-class.component.scss']
    })
    export class MyClassComponent implements OnInit {
      constructor(private router: Router) {}
    
      ngOnInit(): void {
        this.router.events
        .pipe(filter(event => event instanceof NavigationEnd))  
        .subscribe((event: NavigationEnd) => {
          // code goes here...
        });
      }
    }

我会这样写:

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

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