Angular 嵌套组件路由

Question

我有一个导航栏组件，它有一个 routerLink

 <p>
  <a routerLink="/user">User</a>
</p>

以及我正在向其传递值的 UserComponent 下的嵌套组件

@Component({
  selector: 'app-user',
  template: `
    <input #box (keyup.enter)="onEnter(box.value)">
    <div *ngIf="box.size > 0">
      <app-order [value]="value"></app-order>
    </div>`

})
export class UserComponent implements OnInit {

  value = '';

  onEnter(value: string) {
    this.value = value;
  }

  constructor() {
  }

  ngOnInit() {
  }

}

订单组件

@Component({
  selector: 'app-order',
  template:`{{id}}`
})
export class OrderComponent implements OnInit {

  @Input() id:String;

  constructor() { }

  ngOnInit() {
  }

}

现在，当我输入用户链接时，我会看到链接和传递的值。当我再次单击该链接时，我将获得具有价值的相同页面。如何更改此行为，以便当我再次单击路由按钮时，我得到没有传递值的输入？

Answer 1

我在点击导航栏上的相关按钮时尝试刷新页面时遇到了同样的问题。

Angular 声明在同一个 URL 上的导航没有任何效果，因为应用程序的状态由它的当前 URL 表示。

有一个解决方法：onSameUrlNavigation

不幸的是，这个选项只允许守卫和解析器在导航到相同的 URL 时再次运行，所以如果你激活它，你会发现......什么都没有！

所以我用这个类创建了自己的解决方法：

/**
 * Abstract class that allows derived components to get refreshed automatically on route change.
 * The actual use case is : a page gets refreshed by navigating on the same URL and we want the rendered components to refresh
 */
export abstract class AutoRefreshingComponent implements OnInit, OnDestroy {
  public routerEventsSubscription: Subscription;
  protected router: Router;

  constructor() { 
    this.router = AppInjector.get(Router);
  }

  /**
   * Initialization behavior. Note that derived classes must not implement OnInit.
   * Use initialize() on derived classes instead.
   */
  ngOnInit() {
    this.initialize();
    this.routerEventsSubscription = this.router.events.filter(x => x instanceof NavigationEnd).subscribe(res => {
      this.initialize();
    });
  }

  /**
   * Destruction behavior. Note that derived classes must not implement OnDestroy.
   * Use destroy() on derived classes instead.
   */
  ngOnDestroy(): void {
    this.routerEventsSubscription.unsubscribe();
    this.destroy();
  }

  /**
   * Function that allows derived components to define an initialization behavior
   */
  abstract initialize(): void;

  /**
   * Function that allows derived components to define a destruction behavior
   */
  abstract destroy(): void;

}

AppInjector 指的是这个：

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

/**
 * Allows for retrieving singletons using `AppInjector.get(MyService)` (whereas
 * `ReflectiveInjector.resolveAndCreate(MyService)` would create a new instance
 * of the service).
 */
export let AppInjector: Injector;

/**
 * Helper to access the exported {@link AppInjector}, needed as ES6 modules export
 * immutable bindings; see http://2ality.com/2015/07/es6-module-exports.html
 */
export function setAppInjector(injector: Injector) {
    if (AppInjector) {
        // Should not happen
        console.error('Programming error: AppInjector was already set');
    }
    else {
        AppInjector = injector;
    }
}

在您的 AppModule 中：

import { setAppInjector } from './app.injector';

// ...

export class AppModule {
  constructor(private injector: Injector) {
    setAppInjector(injector);
  }
}

然后让所有需要的组件扩展AutoRefreshingComponent。

在你的情况下：

@Component({
  selector: 'app-user',
  template: `
    <input #box (keyup.enter)="onEnter(box.value)">
    <div *ngIf="box.size > 0">
      <app-order [value]="value"></app-order>
    </div>`

})
export class UserComponent extends AutoRefreshingComponent {

  value = '';

  onEnter(value: string) {
    this.value = value;
  }

  constructor() {
  }

  initialize() {
     // Reset your box value
  }

  destroy() {
  }

}

这对于您想要实现的目标可能有点过头了，但每次您想在相同的 URL 导航上刷新组件时它都会很有用。

如果这有帮助，请告诉我。