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Angular路由

路由简介

路由是实现单页面应用的一种方式,通过监听hash或者history的变化,渲染不同的组件,起到局部更新的作用,避免每次URL变化都向服务器请求数据。

路由配置

配置路由模块:approuter.module.ts

const routes: Routes = [
    { path: "first", component: FirstComponent },
    { path: "parent", component: SecondComponent }
]
@NgModule({
    imports: [
        CommonModule,
        // RouterModule.forRoot方法会返回一个模块,其中包含配置好的Router服务
        // 提供者,以及路由库所需的其它提供者。
        RouterModule.forRoot(routes, {
            // enableTracing: true, // <-- debugging purposes only
            // 配置所有的模块预加载,也就是懒加载的模块,在系统空闲时,把懒加载模块加载进来
            // PreloadAllModules 策略不会加载被CanLoad守卫所保护的特性区。
            preloadingStrategy: PreloadAllModules
          })
    ],
    exports: [
        FirstComponent,
        SecondComponent,
        RouterModule
    ],
    declarations: [
        FirstComponent,
        SecondComponent
    ]
})
export class ApprouterModule { }
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app.module.ts中引入改模块:

imports: [ ApprouterModule ]
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重定向路由:

const routes: Routes = [
    { path: "", redirectTo: "first", pathMatch: "full" }
]
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通配符路由:

const routes: Routes = [
    // 路由器会使用先到先得的策略来选择路由。 由于通配符路由是最不具体的那个,因此务必确保它是路由配置中的最后一个路由。
    { path: "**", component: NotFoundComponent }
]
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路由懒加载;

配置懒加载模块可以使得首屏渲染速度更快,只有点击懒加载路由的时候,对应的模块才会更改。

const routes: Routes = [
    {
        path: 'load',
        loadChildren: () => import('./load/load.module').then(m => m.ListModule),
        // CanLoadModule如果返回false,模块里面的子路由都没有办法访问
        canLoad: [CanLoadModule]
    },
]
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懒加载模块路由配置:

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { LoadComponent } from './Load.component';
import { RouterModule, Routes } from '@angular/router';
import { LoadTwoComponent } from '../../../app/components/LoadTwo/LoadTwo.component';
import { LoadOneComponent } from '../../../app/components/LoadOne/LoadOne.component';

const routes: Routes = [
    {
        path: "",
        component: LoadComponent,
        children: [
            { path: "LoadOne", component: LoadOneComponent },
            { path: "LoadTwo", component: LoadTwoComponent }
        ]
    },

]

@NgModule({
    imports: [
        CommonModule,
        //子模块使用forChild配置
        RouterModule.forChild(routes)
    ],

    declarations: [
        LoadComponent,
        LoadOneComponent,
        LoadTwoComponent
    ]
})
export class LoadModule { }

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懒加载模块路由导航:

<a [routerLink]="[ 'LoadOne' ]">LoadOne</a>
<a [routerLink]="[ 'LoadTwo' ]">LoadTwo</a>
<router-outlet></router-outlet>
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路由参数传递:

const routes: Routes = [
    { path: "second/:id", component: SecondComponent },
]
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//routerLinkActive配置路由激活时的类
<a [routerLink]="[ '/second', 12 ]" routerLinkActive="active">second</a>   
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获取路由传递的参数:

import { ActivatedRoute, ParamMap, Router } from '@angular/router';
import { Component, OnInit } from '@angular/core';
import { switchMap } from 'rxjs/operators';

@Component({
    selector: 'app-second',
    templateUrl: './second.component.html',
    styleUrls: ['./second.component.scss']
})
export class SecondComponent implements OnInit {

    constructor(private activatedRoute: ActivatedRoute, private router: Router) { }

    ngOnInit() {

        console.log(this.activatedRoute.snapshot.params);  //{id: "12"}
        // console.log(this.activatedRoute);
        // 这种形式可以捕获到url输入 /second/18 然后点击<a [routerLink]="[ '/second', 12 ]">second</a>   
        // 是可以捕获到的。上面那种是捕获不到的。因为不会触发ngOnInit,公用了一个组件实例。
        this.activatedRoute.paramMap.pipe(
            switchMap((params: ParamMap) => {
                console.log(params.get('id'));
                return "param";
        })).subscribe(() => {

        })
    }
    gotoFirst() {
        this.router.navigate(["/first"]);
    }

}
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queryParams参数传值,参数获取也是通过激活的路由的依赖注入

<!-- queryParams参数传值 -->
<a [routerLink]="[ '/first' ]" [queryParams]="{name: 'first'}">first</a>   
<!-- ts中传值 -->
<!-- this.router.navigate(['/first'],{ queryParams: { name: 'first' }); -->
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路由守卫:canActivate,canDeactivate,resolve,canLoad

路由守卫会返回一个值,如果返回true继续执行,false阻止该行为,UrlTree导航到新的路由。 路由守卫可能会导航到其他的路由,这时候应该返回false。路由守卫可能会根据服务器的值来 决定是否进行导航,所以还可以返回Promise或 Observable,路由会等待 返回的值是true还是false。 canActivate导航到某路由。 canActivateChild导航到某子路由。

const routes: Routes = [
    {
        path: "parent",
        component: ParentComponent,
        canActivate: [AuthGuard],
        children: [
            // 无组件子路由
            {
                path: "",
                canActivateChild: [AuthGuardChild],
                children: [
                    { path: "childOne", component: ChildOneComponent },
                    { path: "childTwo", component: ChildTwoComponent }
                ]
            }
        ],
        // 有组件子路由
        // children: [
        //     { path: "childOne", component: ChildOneComponent },
        //     { path: "childTwo", component: ChildTwoComponent }
        // ]
    }
]
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import { Injectable } from '@angular/core';
import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot } from '@angular/router';

@Injectable({
  providedIn: 'root',
})
export class AuthGuard implements CanActivate {
  canActivate(
    next: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): any {
    // return true;
    // 返回Promise的情况
    return new Promise((resolve,reject) => {
        setTimeout(() => {
            resolve(true);
        }, 3000);
    })
  }
}
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import { Injectable } from '@angular/core';
import {
  ActivatedRouteSnapshot,
  RouterStateSnapshot,
  CanActivateChild
} from '@angular/router';

@Injectable({
  providedIn: 'root',
})
export class AuthGuardChild implements CanActivateChild {
  constructor() {}


  canActivateChild(
    route: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): boolean {
    return true;
  }
}
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parent.component.html路由导航:

<!-- 使用相对路径 -->
<a [routerLink]="[ './childOne' ]">one</a>
<!-- 使用绝对路径 -->
<a [routerLink]="[ '/parent/childTwo' ]">two</a>
<router-outlet></router-outlet>
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canDeactivate路由离开,提示用户没有保存信息的情况。

const routes: Routes = [
    { path: "first", component: FirstComponent, canDeactivate: [CanDeactivateGuard] }
]
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import { FirstComponent } from './components/first/first.component';
import { RouterStateSnapshot } from '@angular/router';
import { ActivatedRouteSnapshot } from '@angular/router';
import { Injectable } from '@angular/core';
import { CanDeactivate } from '@angular/router';

@Injectable({
    providedIn: 'root',
})
export class CanDeactivateGuard implements CanDeactivate<any> {
    canDeactivate(
        component: any,
        route: ActivatedRouteSnapshot,
        state: RouterStateSnapshot
    ): boolean {
        // component获取到组件实例
        console.log(component.isLogin);
        return true;
    }
}
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canLoad是否能进入懒加载模块:

const routes: Routes = [
    {
        path: 'load',
        loadChildren: () => import('./load/load.module').then(m => m.LoadModule),
        // CanLoadModule如果返回false,模块里面的子路由都没有办法访问
        canLoad: [CanLoadModule]
    }
]
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import { Route } from '@angular/compiler/src/core';
import { Injectable } from '@angular/core';
import { CanLoad } from '@angular/router';


@Injectable({
    providedIn: 'root',
})
export class CanLoadModule implements CanLoad {
    canLoad(route: Route): boolean {

        return true;
      }
}
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resolve配置多久后可以进入路由,可以在进入路由前获取数据,避免白屏

const routes: Routes = [
    { path: "resolve", component: ResolveDemoComponent, resolve: {detail: DetailResolver} 
]
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import { Injectable } from '@angular/core';
import { Resolve, ActivatedRouteSnapshot, RouterStateSnapshot } from '@angular/router';

@Injectable({ providedIn: 'root' })
export class DetailResolver implements Resolve<any> {

  constructor() { }

  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): any {
    return new Promise((resolve,reject) => {
        setTimeout(() => {
            resolve("resolve data");
        }, 3000);
    })
  }
}
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ResolveDemoComponent获取resolve的值

constructor(private route: ActivatedRoute) { }
ngOnInit() {
    const detail = this.route.snapshot.data.detail;
    console.log(detail);
}
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监听路由事件:

constructor(private router: Router) {
    this.router.events.subscribe((event) => {
        // NavigationEnd,NavigationCancel,NavigationError,RoutesRecognized
        if (event instanceof NavigationStart) {
            console.log("NavigationStart");
        }
    })
}
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