Angular2 路由器：错误：找不到加载“InboxComponent”的主要出口

Question

我创建了一个带有路由的简单应用。 链接“http://localhost:4200”和“http://localhost:4200/mail”运行良好，

但是当我尝试打开链接“http://localhost:4200/mail/inbox”时，我收到错误消息：“无法找到加载'InboxComponent'的主要出口”。 p>

导致错误的原因以及如何解决？

这是我的 *.ts 文件：

app.module.ts：

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { RouterModule } from '@angular/router';

import { AppComponent } from './app.component';
import { MailListComponent } from './components/mail-list/mail-list.component';
import { FoldersComponent } from './components/folders/folders.component';
import { InboxComponent } from './components/inbox/inbox.component';

const routes = [
  { path: '',
    component: MailListComponent
   },

  { path: 'mail', component: MailListComponent,
      children: [
        {path: 'inbox', component: InboxComponent}
      ]
  }
];

@NgModule({
  declarations: [
    AppComponent,
    MailListComponent,
    FoldersComponent,
    InboxComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    RouterModule.forRoot(routes)
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

app.component.ts：

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  template: `
    <app-folders></app-folders>
    <router-outlet></router-outlet>
  `,
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'app works!';
}

folders.component.ts：

import { Component } from '@angular/core';

@Component({
  selector: 'app-folders',
  template: `
    <aside class="folders">
      <ul>
        <li><a routerLink="mail/inbox">Inbox</a></li>
      </ul>
    </aside>
  `,
  styleUrls: ['./folders.component.css']
})
export class FoldersComponent {
  folders: any[];

  constructor() { }

}

ma​​il-list.component.ts：

import { Component } from '@angular/core';

@Component({
  selector: 'app-mail-list',
  template: `
    <p>
      Mail list works!
    </p>
  `,
  styleUrls: ['./mail-list.component.css']
})
export class MailListComponent {

  constructor() { }

}

inbox.component.ts：

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-inbox',
  template: `
    <p>
      inbox works!
    </p>
  `,
  styleUrls: ['./inbox.component.css']
})
export class InboxComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

}

Answer 1

如果您想避免添加<router-outlet></router-outlet>，另一种方法是将您定义路由的方式更改为以下内容：

const routes = [
  { path: '',
    children: [
      {
        path: '',
        component: MailListComponent
      }
    ]
  },
  { path: 'mail', 
    children: [
      {
        path: '',
        component: MailListComponent
      },
      {
        path: 'inbox', 
        component: InboxComponent
      }
    ]
  }
];

这将允许您使用与上述相同的<router-outlet></router-outlet> 来托管新组件

Answer 2

您的MailListComponent 也需要<router-outlet>，因为InboxComponent 在您的路由器配置中被定义为子级：

@Component({
  selector: 'app-mail-list',
  template: `
    <p>
      Mail list works!
    </p>
    <router-outlet></router-outlet>
  `,
  styleUrls: ['./mail-list.component.css']
})
export class MailListComponent {

  constructor() { }

}

但是，如果您想在同一个插座中呈现 InboxComponent，则不应将其添加为子项