如何返回最后一页

是的，你能做到。在你的typescript组件上编写这段代码，然后享受吧!

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


@Component({
selector: 'return_page',
template: `<button mat-button (click)="onReturn()">Back</button>`,
})
export class ReturnPageComponent {
constructor(private location: Location) { }


onReturn() {
this.location.back();
}
}

也许你想检查之前的历史点是否在你的应用程序中。例如，如果你直接进入你的应用程序并执行location.back()(例如，在工具栏中按<- back按钮)，你会回到浏览器的主页面，而不是去其他地方在你的应用程序。

这是我检查这个的方法:

import { Component } from '@angular/core';
import { ActivatedRoute, Router } from '@angular/router';
import { Location } from '@angular/common';


@Component({
selector: 'app-foo',
template: ''
})
export class FooComponent {


private readonly canGoBack: boolean;


constructor(
private readonly route: ActivatedRoute,
private readonly router: Router,
private readonly location: Location
) {
// This is where the check is done. Make sure to do this
// here in the constructor, otherwise `getCurrentNavigation()`
// will return null.
this.canGoBack = !!(this.router.getCurrentNavigation()?.previousNavigation);
}


goBack(): void {
if (this.canGoBack) {
// We can safely go back to the previous location as
// we know it's within our app.
this.location.back();
} else {
// There's no previous navigation.
// Here we decide where to go. For example, let's say the
// upper level is the index page, so we go up one level.
this.router.navigate(['..'], {relativeTo: this.route});
}
}


}

我们检查加载当前路由的导航是否有前一个兄弟。这必须在导航过程仍处于活动状态时在构造函数中完成。

但也有一些注意事项:

• canGoBack将为false，即使之前的位置实际上在我们的应用程序但中，页面被刷新。
• 用户可能想要“返回”;通过点击浏览器的返回按钮回到上一页(goBack()出现的地方)，但由于应用程序返回历史，而不是按下一个新位置，用户将返回更远，可能会感到困惑。

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
}
}

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();
});
});

如果你使用的是最新的Angular/TypeScript，请确保你显式导入

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

而且

 onCancel() {
this.location.back();
}

尝试routerLink =“. . / LASTPAGE"

例如，从子路由返回到父路由

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

你也可以阅读之前的导航

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

我想出了这个，你也可以检查是否有上一页。 确保在你的appComponent中使用该服务

import { Injectable } from '@angular/core';
import { Location } from '@angular/common';
import { NavigationEnd, Router } from '@angular/router';


interface HistoryData {
previousPage: string | null,
currentPage: string | null,
}


@Injectable({ providedIn: 'root' })
export class GoBackService {


private historyData: HistoryData = { previousPage: null, currentPage: null };


constructor(private router: Router, private location: Location) {
this.router.events.subscribe((event) => {
if (event instanceof NavigationEnd) {
this.historyData.previousPage = this.historyData.currentPage;
this.historyData.currentPage = event.urlAfterRedirects;
}
});
}


public goBack(): void {
if (this.historyData.previousPage) this.location.back();
}


public canGoBack(): boolean {
return Boolean(this.historyData.previousPage);
}


}

只需使用< a href = " https://angular。io / api /共同/位置#回noreferrer“rel = >位置< / >，一个Angular服务，应用程序可以使用它与浏览器的URL进行交互。

导入:

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

注射:

constructor(private location: Location) { }

简单地使用它:

goBack() {
this.location.back(); // Navigates back in the platform's history
}

检测到的未更改组件的@Parziphal答案版本:

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


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