Angular ViewChild 和 ComponentFactoryResolver - 保持状态

Question

我使用此处描述的动态组件方法创建了一个选项卡界面：https://angular.io/guide/dynamic-component-loader。

我的问题是——如何在隐藏时维护一个组件的状态？

我在支持中添加了一些代码

import { Directive, ViewContainerRef } from '@angular/core';

@Directive({
  selector: '[tabs]'
})
export class TabsDirective {

  constructor(public viewContainerRef: ViewContainerRef) { }

}

模板

<div id="tabContent" class="tabContent padded24">
  <ng-template tabs></ng-template>
</div>

组件

@Component({
  selector: 'my-tabs',
  templateUrl: './tabs.component.html',
  styleUrls: ['./tabs.component.css']
})
export class TabsComponent implements OnInit, OnDestroy {

  //Empty array to store list of possible tabs. A variable to store the current tab. A Viewchild to render the appropiate Tab content
  public tabs = []
  currentTab;
  @ViewChild(TabsDirective) Tab: TabsDirective;

  constructor(
    private _tabsService: TabsService,
    private componentFactoryResolver: ComponentFactoryResolver,
  ) { }

  ngOnInit() {
    this.tabs = this._tabsService.getTabItems();
    this.currentTab = this.tabs[0]
  }
  onSelect(tab) {
    this.router.navigate(['/admin', tab.id])
  }
  //Load appropiate tab content depending on select tab 
  loadComponent() {
    var result = this.tabs.filter((obj) => {
      return obj.id == this.currentTab;
    });
    let tabItem = result[0];
    let componentFactory =  this.componentFactoryResolver.resolveComponentFactory(tabItem.component);  
    let viewContainerRef = this.Tab.viewContainerRef;
    viewContainerRef.clear();
    let componentRef = viewContainerRef.createComponent(componentFactory);
  }
}

Answer 1

如果你想在动态创建的组件中添加文本

loadComponent() {
    var result = this.tabs.filter((obj) => {
      return obj.id == this.currentTab;
    });
    let tabItem = result[0];
    let componentFactory =  this.componentFactoryResolver.resolveComponentFactory(tabItem.component);  
    let viewContainerRef = this.Tab.viewContainerRef;
    viewContainerRef.clear();
    let componentRef = viewContainerRef.createComponent(componentFactory);
    componentRef .instance.text = 'Iam dynamically created Text';

  }

更多信息请查看：Angular 2 dynamic tabs with user-click chosen components