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Angular 4删除动态添加的组件

[英]Angular 4 removing dynamically added components

使用类似这样的内容: https : //netbasal.com/dynamically-creating-components-with-angular-a7346f4a982d我要添加多个组件,问题是如何稍后基于单击的内容删除这些组件? 我要尝试做的是创建面包屑,然后在单击面包屑时,将其下面的所有内容全部删除。 要创建它们,我使用以下代码:

createCrumb(name, key, level){
  let data = {name:name, key:key, level,level, diagram: this.diagram};
  const factory = this.this.resolver.resolveComponentFactory(BreadCrumbsButton);
  let componentRef = this.container.createOmponent(factory);
  (<BreadCrumbsButton>componentRef.instance).data = data;
}

所有这些都可以完美地工作,但是我要加倍。 问题是如何在剩下其余部分的同时删除特定的部分?

您可以在上面调用destroy方法:

  createComponent(type) {
    this.container.clear(); 
    const factory: ComponentFactory = this.resolver.resolveComponentFactory(AlertComponent);
    this.componentRef: ComponentRef = this.container.createComponent(factory);

    setTimeout(()=>{
       this.componentRef.destroy(); <--------------------
    }, 2000);
  }

我将超时用于演示目的,以便可以在屏幕上看到呈现的组件。

同时使用演示检查此答案

动态添加和删除角度组件


更新

您现在可以使用subject而不是interface来进行组件的通信

阅读有关RxJS主题的​​信息


从父级移除子级组件,因此必须开始它们之间的通信,但是如何进行呢?

在这种情况下使用接口

发生了什么 ?

父级正在创建子级,当子级尝试删除自己时,它会通过接口告诉其父级删除它,因此父级也会这样做。

import { ComponentRef, ComponentFactoryResolver, ViewContainerRef, ViewChild, Component } from "@angular/core";

// Parent Component
@Component({
    selector: 'parent',
    template: `
    <button type="button" (click)="createComponent()">
        Create Child
    </button>
    <div>
        <ng-template #viewContainerRef></ng-template>
    </div>
  `
})
export class ParentComponent implements myinterface {

    @ViewChild('viewContainerRef', { read: ViewContainerRef }) VCR: ViewContainerRef;

    //manually indexing the child components for better removal
    //although there is by-default indexing but it is being avoid for now
    //so index is a unique property here to identify each component individually.
    index: number = 0;

    // to store references of dynamically created components
    componentsReferences = [];

    constructor(private CFR: ComponentFactoryResolver) {
    }

    createComponent() {

        let componentFactory = this.CFR.resolveComponentFactory(ChildComponent);
        let componentRef: ComponentRef<ChildComponent> = this.VCR.createComponent(componentFactory);
        let currentComponent = componentRef.instance;

        currentComponent.selfRef = currentComponent;
        currentComponent.index = ++this.index;

        // prividing parent Component reference to get access to parent class methods
        currentComponent.compInteraction = this;

        // add reference for newly created component
        this.componentsReferences.push(componentRef);
    }

    remove(index: number) {

        if (this.VCR.length < 1)
            return;

        let componentRef = this.componentsReferences.filter(x => x.instance.index == index)[0];
        let component: ChildComponent = <ChildComponent>componentRef.instance;

        let vcrIndex: number = this.VCR.indexOf(componentRef)

        // removing component from container
        this.VCR.remove(vcrIndex);

        this.componentsReferences = this.componentsReferences.filter(x => x.instance.index !== index);
    }
}


// Child Component
@Component({
    selector: 'child',
    template: `
    <div>
    <h1 (click)="removeMe(index)">I am a Child, click to Remove</h1>
    </div>
    `
})
export class ChildComponent {

    public index: number;
    public selfRef: ChildComponent;

    //interface for Parent-Child interaction
    public compInteraction: myinterface;

    constructor() {
    }

    removeMe(index) {
        this.compInteraction.remove(index)
    }
}

// Interface
export interface myinterface {
    remove(index: number);
}

如果要进行测试,只需创建一个像comp.ts这样的文件,然后将该代码粘贴到该文件中,然后添加对app.module.ts的引用

@NgModule({
  declarations: [

    ParentComponent,
    ChildComponent

  ],
  imports: [

    //if using routing then add like so
    RouterModule.forRoot([
      { path: '', component: ParentComponent },
      { path: '**', component: NotFoundComponent }
    ]),

  ],
  entryComponents: [

    ChildComponent,  

  ],

另外,如果使用ViewContainerRef保留注入的组件,则可以使用clear()方法。

this.container.clear();

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