角度路由-路由到子级时，仅在刷新页面时查看更新

Question

我正在从angular文档的示例中学习路由。问题在于，单击危机列表中的元素时，单击后不会立即显示危机详细信息。如果刷新屏幕，则会显示相关的危机详细信息。

所以问题是为什么刷新后细节可见？解决方案是什么？

// crisis-center-routing-module.ts

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';

import { CrisisCenterHomeComponent } from './crisis-center-home/crisis-center-home.component';
import { CrisisListComponent } from './crisis-list/crisis-list.component';
import { CrisisCenterComponent } from './crisis-center/crisis-center.component';
import { CrisisDetailComponent } from './crisis-detail/crisis-detail.component';

const crisisCenterRoutes: Routes = [
  {
    path: 'crisis-center',
    component: CrisisCenterComponent,
    children: [
      {
        path: '',
        component: CrisisListComponent,
        children: [
          {
            path: ':id',
            component: CrisisDetailComponent
          },
          {
            path: '',
            component: CrisisCenterHomeComponent
          }
        ]
      }
    ]
  }
];

@NgModule({
  imports: [
    RouterModule.forChild(crisisCenterRoutes)
  ],
  exports: [
    RouterModule
  ]
})
export class CrisisCenterRoutingModule { }

// crisis-list.component.html

    <h2>CRISES</h2>
    <ul class="crises">
      <li *ngFor="let crisis of crises$ | async" [class.selected]="crisis.id === selectedId">
        <a [routerLink]="[crisis.id]">
          <span class="badge">{{ crisis.id }}</span>{{ crisis.name }}
        </a>
      </li>
    </ul>
    <router-outlet></router-outlet>

//crisis-list-component.ts

    import { CrisisService } from '../crisis.service';
    import { Crisis } from '../crisis';
    import { Component, OnInit } from '@angular/core';
    import { Observable } from 'rxjs';
    import { switchMap } from 'rxjs/operators';
    import { ActivatedRoute } from '@angular/router';


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

          selectedCrisis: Crisis;

          crises: Crisis[];
          crises$;
          selectedId: number;

          constructor(private crisisService: CrisisService, private service: CrisisService, private route: ActivatedRoute) { }

          ngOnInit() {
            this.crises$ = this.route.paramMap.pipe(
              switchMap(params => {
                this.selectedId = +params.get('id');
                return this.service.getCrises();
              })
            );
          }

          onSelect(crisis: Crisis): void {
            this.selectedCrisis = crisis;
          }

          getCrises(): void {
            this.crisisService.getCrises()
              .subscribe((crises) => {
                this.crises = crises;
              });
          }
        }

// crisis-detail.component.html

<button (click)='gotoCrises(crisis)'>Back</button>

<div *ngIf="crisis">
  <h2>{{crisis.name | uppercase}} Details</h2>
  <div><span>id: </span>{{crisis.id}}</div>
  <div>
    <label>name:
      <input [(ngModel)]="crisis.name" placeholder="name" />
    </label>
  </div>
</div>

// crisis-detail.component.ts

import { Observable } from 'rxjs';
import { CrisisService } from '../crisis.service';
import { Component, OnInit, Input } from '@angular/core';
import { Crisis } from '../crisis';
import { Router, ActivatedRoute, ParamMap } from '@angular/router';
import { switchMap } from 'rxjs/operators';

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

  crisis: Crisis;
  private crisis$;

  constructor(private route: ActivatedRoute, private router: Router, private service: CrisisService) { }

  ngOnInit() {
    const id = this.route.snapshot.paramMap.get('id');
    this.crisis$ = this.service.getCrisis(id);
    this.crisis$.subscribe((crisis) => {
      this.crisis = crisis;
    });
  }

  gotoCrises(crisis: Crisis) {
    const crisisId = crisis ? crisis.id : null;
    this.router.navigate(['/crisises', { id: crisisId, foo: 'foo' }]);
  }

}

Answer 1

问题是我正在使用]从URL获取ID>

activatedRoute.snapshot.paramMap.get（'id）

路由器出口仅渲染一次路由。对于列表中的其他单击，详细信息视图不会更新。

为了不断收听URL中ID的变化，我必须订阅

ActivatedRoute.url

此解决方案很有帮助https://stackoverflow.com/a/47030238/2416260