2022 利用你的应用程序路由-更多的是一种“角度方法”，而不是访问浏览器的位置对象来获取导航历史。 想想你为什么需要用户返回，以及“返回”在应用程序及其路由的更广泛的上下文中意味着什么。

例如，从子路由返回到父路由

  this.router.navigate(['..'], {relativeTo: this.route});

您还可以阅读以前的导航

previousNavigation:先前成功的导航对象。只有 一个先前的导航是可用的，因此这个先前的 Navigation对象的previousNavigation为空值。

此外，您还可以在历史记录为空的情况下使用此服务与回退功能

url-back.service.ts

import { Injectable } from '@angular/core';
import { Location } from '@angular/common';

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

const EMPTY_HISTORY_LENGTH = 2;

/**
 * This service helps to Navigate back to the prev page, and if no prev page,
 * will redirect to the fallback url.
 */
@Injectable()
export class UrlBackService {
  constructor(private router: Router, private location: Location) {}

  /**
   * This method will back you to the previous page,
   * if no previous page exists, will redirect you to the fallback url.
   * @param href - url, if tryNativeFirst is provided, this is fallback url
   * @param tryNativeFirst - try to go back natively using browser history state.
   */
  back(href: string, tryNativeFirst: boolean = false) {
    if (tryNativeFirst) {
      if (history.length === EMPTY_HISTORY_LENGTH) {
        this.router.navigate(UrlBackService.urlToArray(href));
      } else {
        this.location.back();
      }
    } else {
      this.router.navigate(UrlBackService.urlToArray(href));
    }
  }

  /**
   * In case that router.navigate method tries to escape all '/' in the string,
   * was decided to split string to array, and if URL starts or ends with slash - remove them, eg:
   * /my/url will be split to ['', 'my', 'url'], so we need to remove empty spaces use filter function.
   * @param href
   * @private
   */
  private static urlToArray(href: string) {
    return href.split('/').filter((notEmpty) => notEmpty);
  }
}

url-back.service.spec.ts

import { TestBed } from '@angular/core/testing';

import { UrlBackService } from './url-back.service';
import { Router } from '@angular/router';
import { Location } from '@angular/common';
import { RouterTestingModule } from '@angular/router/testing';

describe('UrlBackService', () => {
  let service: UrlBackService;
  let router: Router;
  let location: Location;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [RouterTestingModule],
      providers: [UrlBackService],
    });
    service = TestBed.inject(UrlBackService);
    router = TestBed.inject(Router);
    location = TestBed.inject(Location);
  });

  it('should be created', () => {
    expect(service).toBeTruthy();
  });

  it('no meter what history state is, it should be redirected to the /my/url', () => {
    spyOn(router, 'navigate');
    service.back('/my/url');
    expect(router.navigate).toHaveBeenCalledWith(['my', 'url']);
  });

  it('in case history is empty push to /my/url', () => {
    spyOn(router, 'navigate');
    service.back('/my/url', true);
    expect(router.navigate).toHaveBeenCalledWith(['my', 'url']);
  });

  it('in case history is NOT empty push to url1', () => {
    spyOn(location, 'back');
    window.history.pushState(null, '', 'url1');

    service.back('/my/url', true);
    expect(location.back).toHaveBeenCalled();
  });
});

从beta 18开始:

import {Location} from 'angular /platform/common';

我是这么说的:

import { Location } from '@angular/common'
import { Component, Input } from '@angular/core'

@Component({
    selector: 'Back_page',
    template: `<button  (click)="onBack()">Back</button>`,
})
export class BackPageComponent {
  constructor(private location: Location) { }

  onBack() {
    this.location.back();// <-- go back to previous location
  }
}

在Angular 2的最终版本中。X / 4。x -这里是文档https://angular.io/api/common/Location

/* typescript */

import { Location } from '@angular/common';
// import stuff here

@Component({
// declare component here
})
export class MyComponent {

  // inject location into component constructor
  constructor(private location: Location) { }

  cancel() {
    this.location.back(); // <-- go back to previous location on cancel
  }
}

进口:

import { Location } from '@angular/common';
import { Router } from '@angular/router';

构造函数:

constructor(private readonly router: Router, private readonly location: Location) {
  location.onUrlChange(() => this.canGoBack = !!this.router.getCurrentNavigation()?.previousNavigation);
}

可选，避免返回到应用程序之外:

private canGoBack: boolean = false;

constructor(private router:Router,private location:Location){
  this.canGoBack = !!(this.router.getCurrentNavigation()?.previousNavigation);
}

返回:

goBack(): void {
  if (this.canGoBack) {
    this.location.back();
  }
}

Html:

<button (click)="goBack()"></button>