Question

我有一个带有一个routerLink的导航栏组件

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

以及要向其传递值的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() {
  }

}

OrderComponent

@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，将获得包含链接和传递值的视图。当我再次单击链接时，我得到的页面具有价值。如何更改此行为，以便再次单击“路由”按钮时得到的输入内容没有传递值？

Answer 1

当单击导航栏上与其相关的按钮时尝试刷新页面时，遇到了相同的问题。

Angular指出，由于应用程序的状态由其当前URL表示，因此在相同URL上的导航无效。

有一个解决方法：onSameUrlNavigation

不幸的是，此选项仅允许保护者和解析器在导航到相同URL时再次运行，因此，如果激活它，您将发现...什么都没有！

所以我用此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引用此：

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);
  }
}

然后使所有需要的组件扩展AutoRefreshingComponent。

在您的情况下：

@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() {
  }

}

对于您想要实现的目标来说，这可能是多余的，但是每次您要在相同的URL导航上刷新组件时，它都会很有用。

让我知道这是否有帮助。

角嵌套组件布线

1 个答案: