组件未接收到指令事件

Question

我有一个用户搜索功能，在搜索词字段上有一个去抖动指令：

<mat-form-field>
    <input matInput [(ngModel)]="searchTerm" (appOnDebounce)="search($event)" placeholder="Search..." autocomplete="off">
</mat-form-field>

应该调用方法：

search(searchTerm: string): void {
  console.log('Searching for ' + searchTerm);
}

指令实现为：

@Directive({
  selector: '[ngModel][appOnDebounce]'
})
export class DebounceDirective implements OnInit, OnDestroy {

  @Output()
  public debounceEvent: EventEmitter<string>;

  @Input()
  public debounceTime = 300;

  private isFirstChange = true;
  private subscription: Subscription;

  constructor(public model: NgControl) {
    this.debounceEvent = new EventEmitter<string>();
  }

  ngOnInit() {
    this.subscription = this.model.valueChanges
      .debounceTime(this.debounceTime)
      .distinctUntilChanged()
      .subscribe((modelValue: string) => {
        if (this.isFirstChange) {
          this.isFirstChange = false;
        } else {
          console.log(modelValue);
          this.debounceEvent.emit(modelValue);
        }
      });
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }

}

当记录器语句显示输入的字符串时，指令正确发出事件，但从未调用 search(searchTerm: string): void {} 方法。

Answer 1

像这样更改 debounceEvent 的修饰符属性

@Output('appOnDebounce')
public debounceEvent: EventEmitter<any>;

请在此处查看示例解决方案https://ng2-debounce-sample.stackblitz.io

组件未接收到指令事件

Directive event not being received by the component

angular-directive

angular7