angular2 - 从父路由到子路由的值传递 [英] angular2 - Pass value from parent route to child route

问题描述

我有一条名为home的路线，它有三条子路线，文件，邮件和垃圾。在归属路由组件中，它有一个名为user的变量。我知道有一些方法可以在父级和子级组件之间传递信息，这些方法是这里，但我想如何在父/子路线之间传递信息。

I have a route called home and it has three child routes, documents, mail and trash. In the home route component it has a variable called 'user'. I know there are a few ways of passing info between parent and child components highlighted here, but how am I suppose to pass info between parent/child routes.

{ path: 'home',  component: HomeComponent, children: [
        { path: 'documents',  component: DocumentsComponent },
        { path: 'mail',  component: MailComponent },
        { path: 'trash',  component: TrashComponent },
    ]
},

服务

import { Injectable } from '@angular/core';
@Injectable()
export class HomeService {
  // Mock user, for testing  
  myUser = {name:"John", loggedIn:true};
  // Is Super Admin
  isLogged():boolean {
    if(this.myUser.role == true){
      return true ; 
    }
    return false ; 
  }
}

组件

  constructor(public router: Router, public http: Http, private homeService: HomeService) {

  }

  isLogged(){
    return this.homeService.isLogged(); 
  }

模板

<div class="side-nav fixed" >
    <li style="list-style: none">
        <img alt="avatar" class="circle valign profile-image" height="64" src=
        "../images/avatar.jpg" width="64">
        <div class="right profile-name">
            <!-- Value not changing even with service --> 
            {{myUser.role}} 
        </div>
    </li>

推荐答案

您可以使用公共服务传递数据，如 Angular Documentation

You may use a common service to pass data like explained in the Angular Documentation

基本上你可以创建一个具有用户对象的服务，一旦你的父路由被加载就可以更新或对父组件采取某些措施。

Basically you may create a Service which will have a user object, which can be updated once your parent route gets loaded or with some action on parent component.

UserService

   import { Injectable } from '@angular/core';
   import { Subject }    from 'rxjs/Subject';

   @Injectable()
   export class UserService {
     // Observable user 
     user = new Subject<string>();
   }

然后当加载子路径组件时，您可以从中检索值服务。

And then when the child route component gets loaded you may retrieve the value from the Service.

HomeComponent

 @Component({
   ... 
 })
 export class HomeComponent{
   ... 
   constructor(private userService:UserService ){}
   someMethod = () =>{
      this.userService.user.next(<pass user object>);
   }
 }

MailComponent

 @Component({
   ... 
 })
 export class HomeComponent{
   ... 
   constructor(private userService:UserService ){
     this.userService.user.subscribe(userChanged);  
   }

   userChanged = (user) => {
     // Do stuff with user
   }
 }

如果您在父级中添加提供程序，则服务对象将与子级中的实例相同。

Service object will be same instance in child if you add the provider in the parent.

希望这有助于!!

这篇关于angular2 - 从父路由到子路由的值传递的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！