[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。
您现在可以使用subject
而不是interface
来进行组件的通信
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,
],
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.