简体   繁体   中英

How to navigate/focus to the next item in Angular2?

I want to focus to the next item using Arrow keys.
In keydown event handler, I use event.currentTarget.nextSibling to access the next item.
Is there another way to accomplish this?
In the event handler, I want to use JQuery to do this. How to do this?

<ul>
    <li *ngFor = "let work of works" tabindex="-1" 
        (keydown.ArrowDown)="handleKeyEvent( $event, 'Arrow Down' )">
        <div class="guide-label">
            <div>{{work.cd}}</div>
            <div>{{work.name}}</div>
        </div>
    </li>
</ul>
export class WorkComponent {
    ...
    handleKeyEvent(event: Event): void {

        event.currentTarget.nextSibling.focus();
        event.preventDefault();
    }
}

Create a focus directive (and register it in your NgModule ) that calls focus() on the host element when the input value changes to true :

@Directive({
  selector : '[myFocus]'
})
class MyFocus {
  constructor(public renderer: Renderer, public elementRef: ElementRef) {}

  @Input()
  set myFocus(value :boolean) {
    if(value) {
      this.renderer.invokeElementMethod(
          this.elementRef.nativeElement, 'focus', []);
    }
  }
}

Add the selector and a binding that passes true or false to the directive when it is supposed to be focused:

<li *ngFor = "let work of works let idx=index" tabindex="-1" 
    [myFocus]="idx == focusedIdx" (keydown.ArrowDown)="handleKeyEvent( $event, 'Arrow Down' )">

Update focusedIdx on key events:

       handleKeyEvent(event: Event): void {
            this.focusedIdx++;
        }

See also Angular 2: Focus on newly added input element

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM