路由守卫

使用场景

分三种方式

案例：
1、CanActivate 路由守卫用法
在app内新增文件夹guard
新建login.guard.ts 模拟登陆状态；
调用CanActivate接口，return 的值为true视为登陆成功，可以下一步路由

import {CanActivate} from "@angular/router";

/*实现 CanActivate的接口*/
export class LoginGuard implements CanActivate{
  canActivate(){
    let loggedIn:boolean = Math.random() < 0.5;
    if(!loggedIn){
      console.log('用户未登陆');
    }
    return loggedIn;

  }
}

路由配置app-routing.module.ts如下 ：

....
 {path:'product/:id',component:ProductComponent,children:[
    {path:'',component:ProductDescComponent},
    {path:'seller/:id',component:SellerInfoComponent},
  ],canActivate:[LoginGuard] },

....

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule],
  /*依赖注入*/
  providers:[LoginGuard],
})
....

2、canDeactivate路由守卫用法
在当前路由离开前， 做相关守卫，如提供客户还没保存，return值为true才通过。
示例：新建unsaved.guard.ts文件

import {CanDeactivate} from "@angular/router";
import {ProductComponent} from "../product/product.component";

/*   <ProductComponent>  是泛型写法 */

export class UnsavedGuard implements CanDeactivate<ProductComponent>{
  canDeactivate(component: ProductComponent){
    return window.confirm("还没有保存");
  }
}

路由配置app-routing.module.ts如下 ：

...
 {path:'product/:id',component:ProductComponent,children:[
    {path:'',component:ProductDescComponent},
    {path:'seller/:id',component:SellerInfoComponent},
  ],canActivate:[LoginGuard],
    canDeactivate:[UnsavedGuard]
  },
...
@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule],
  /*依赖注入*/
  providers:[LoginGuard,UnsavedGuard],
})

3、Resolve 守卫，在路由激活前获取数据给模块渲染

3.1在guard中新建product.resolve.ts定义逻辑

import {ActivatedRouteSnapshot, Resolve, Router, RouterStateSnapshot} from "@angular/router";
import {Product} from "../product/product.component";
import {Injectable} from "@angular/core";

@Injectable()
export class ProductResolve implements Resolve<Product>{

  constructor(private router:Router){

  }

  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot){
    let productId:number = route.params['id'];
    if(productId == 1){
      return new Product(1,'iPhone7');
    }else{
      this.router.navigate(['/home']);
      return undefined;
    }

  }

}

3.2 在product组件中定义Product对象

import { Component, OnInit } from '@angular/core';
import {ActivatedRoute, Params} from "@angular/router";

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

  private productId:number;//定义接收的ID变量
  private productName:string;//定义接收的productName变量
  constructor(private routeInfo:ActivatedRoute) { }

  ngOnInit() {
    /* 通过参数订阅取得数据 */
    this.routeInfo.params.subscribe((param:Params)=>this.productId = param['id']);
    this.routeInfo.data.subscribe((data:{product:Product})=>{
      this.productId = data.product.id;
      this.productName = data.product.name;
    })
    /*通过 queryParams 方法取得参数快照*/
    // this.productId = this.routeInfo.snapshot.params['id'];
  }

}

3.3在product组件模板中定义输出变量

<div class="product">
  <p>
    这是一个商品组件
  </p>

  <p>
    查询参数传递过来的组件ID：{{productId}}
  </p>
 <p>
    商品名称是：{{productName}}
  </p>

  <br>

  <hr>

  <a [routerLink]="['./']">商品的描述</a>
  <a [routerLink]="['./seller',99]">销售员信息</a>

  <router-outlet></router-outlet>
</div>

3.4 在app-routing.module.ts中定义调用

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import {HomeComponent} from "./home/home.component";
import {ProductComponent} from "./product/product.component";
import {Code404Component} from "./code404/code404.component";
import {ProductDescComponent} from "./product-desc/product-desc.component";
import {SellerInfoComponent} from "./seller-info/seller-info.component";
import {ChatComponent} from "./chat/chat.component";
import {LoginGuard} from "./guard/login.guard";
import {UnsavedGuard} from "./guard/unsaved.guard";
import {ProductResolve} from "./guard/product.resolve";

const routes: Routes = [
  {path:'',redirectTo:'/home',pathMatch:'full'},
  {path:'chat',component:ChatComponent,outlet:'aux'},
  {path:'home',component:HomeComponent},
  {path:'product/:id',component:ProductComponent,children:[
    {path:'',component:ProductDescComponent},
    {path:'seller/:id',component:SellerInfoComponent},
  ],resolve:{
    product:ProductResolve
  }
  },

  /* 路由配 通配符路由通常放最后面 */
  {path:'**',component:Code404Component},
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule],
  /*依赖注入*/
  providers:[LoginGuard,UnsavedGuard,ProductResolve],
})
export class AppRoutingModule { }

路由部分源码：
链接: https://pan.baidu.com/s/1bBZYJs 密码: ukwe