为组件的每个实例触发Angular事件处理程序

时间:2019-10-23 19:51:00

标签: angular events event-handling components

我有一个页面(主机视图),在其中我动态创建包含信息的组件,这些组件包括用户在UI中创建的p树。我从主机视图中添加了一个按钮,并在树组件上单击了按钮,将它们删除,该组件通过notificationService将事件传递回主机视图,如下所示:

在主机视图中创建:

constructor(@Inject(Loader) service, @Inject(ViewContainerRef) viewContainerRef, public dataCenter: DataCenterService,private router: Router) {
    this.service = service;
    this.trees = this.dataCenter.getTreeState();
    this.service.setRootViewContainerRef(viewContainerRef)
    this.newTree();
}



newTree() {
    var newTree = this.service.addDynamicComponent();
    newTree.instance.ref = newTree;

    newTree.instance.service.onDestroyEvent.subscribe(
      treeRef => {
        for(var i=0;i<this.trees.length; i++){
          if(this.trees[i].instance.ref == treeRef){
            this.trees.splice(i,1);
          }
        }
       }
      );
    this.trees.push(newTree);
}

通知服务:

export class NotificationService {
    onDestroyEvent: EventEmitter<ComponentRef<ConnectionTreeComponent>> = new EventEmitter();
    constructor() {}
}

树组件:

service:NotificationService;

constructor(public dataCenter: DataCenterService, public treeService: TreeDragDropService, service:NotificationService) {
   this.service = service; 
}

ngOnDestroy() {
   this.service.onDestroyEvent.emit(this.ref); /*ComponentRef passed back to hostview*/
}

因此这在技术上确实有效,但是对于树组件的每个实例都调用一次,而不是一次。我该如何解决才能正常工作?

1 个答案:

答案 0 :(得分:0)

我删除了NotificationService并将onDestroyEvent放入树组件中,并进行了相应的重构。这样就解决了重复事件的问题。