[Angular] Angular Custom Change Detection with ChangeDetecto
Each component has its own?ChangeDetectorRef,and we can inject?ChangeDetectorRef into constructor: export class ChildComponent implements OnInit { constructor( private cdr: ChangeDetectorRef ) ? For example if you have a huge list can be updated in real time though some real time database. Update in real time is really expensive for huge list.? ? We have build a custom change detector,for example,update every 5 seconds,to check changes,to do that,we need to two things, 1. Disable default change detector 2. Check for changes every 5 seconds. import { Component,OnInit,ChangeDetectorRef } from ‘@angular/core‘; import { ListService } from ‘./list.service‘; @Component({ selector: ‘app-child‘,templateUrl: ‘./child.component.html‘,styleUrls: [‘./child.component.css‘] }) export class ChildComponent implements OnInit { constructor( private cdr: ChangeDetectorRef,private dataProvider: ListService ) { // disable default change detector cdr.detach(); // now every 5second,do a check for its child tree setInterval(() => { this.cdr.detectChanges(); },5000); } ngOnInit() { } } ? There is another API: reattach() which uses for reset to default Angular change dectctor. (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |