在该方法中,可以执行一些初始化操作,例如获取数据、订阅事件、初始化变量等。 在Angular中,每个组件都可以实现ngOnInit方法,并在该方法中编写组件初始化的逻辑。当组件被创建后,Angular会自动调用ngOnInit方法。 以下是ngOnInit方法的一般用法: 代码语言:txt 复制 import { Component, OnInit } from '@angular/cor...
复制 import{ComponentFixture,TestBed}from'@angular/core/testing';import{MyComponent}from'./my.component';describe('MyComponent',()=>{letcomponent:MyComponent;letfixture:ComponentFixture<MyComponent>;beforeEach(async()=>{awaitTestBed.configureTestingModule({declarations:[MyComponent]}).compileComponen...
// parent.component.ts import { Component } from '@angular/core'; @Component({ selector: 'exe-parent', template: ` Hello {{name}} `, }) export class ParentComponent { name: string; constructor() { this.name = 'God eyes'; } } // child.component.ts import { Component, Input, On...
那么用到组件间通信的方法我们可以放在ngOnInit中去执行,比如异步请求等: import{Component,ElementRef,OnInit}from'@angular/core';@Component({selector:'my-app',template:`Welcome to Angular World Hello {{name}}`,})exportclassAppComponentimplementsOnInt{name:string='';constructor(publicelementRef:ElementRe...
import{Component,Input,OnInit}from'@angular/core';@Component({selector:'exe-child',template:`父组件的名称:{{pname}} `})exportclassChildComponentimplementsOnInit{@Input()pname:string;// 父组件的名称constructor(){console.log('ChildComponent constructor',this.pname);// Output:undefined...
import{Component,OnInit}from'@angular/core'; @Component({selector:'hello-world',templateUrl:'hello-world.html'})classHelloWorldimplementsOnInit{constructor() { }ngOnInit() {console.log('ngOnInit被Angular调用'); } } constructor适用场景
import{Component}from'@angular/core';@Component({selector:'my-parent',template:`<my-child [pid]="id"></my-child>`,})exportclassParentComponent{id:number=0;constructor(){this.id=1;}} 子组件代码: import{Component,Input,OnInit}from'@angular/core';@Component({selector:'my-child',template...
为什么解决了 Injectable 类时没有调用 ngOnInit()? 代码 import {Injectable, OnInit} from 'angular2/core'; import { RestApiService, RestRequest } from './rest-api.service'; @Injectable() export class MovieDbService implements OnInit { constructor(private _movieDbRest: RestApiService){ window...
import{Directive,ElementRef,HostListener,Input,OnDestroy,OnInit}from'@angular/core';import{Subscription}from'rxjs/Subscription';importechartsfrom'echarts';import'echarts/theme/macarons';import{ChartService}from'../service/chart/chart.service'; @Directive({selector:'[appECharts]'})exportclassEChartsDi...
We have to import OnInit like this in order to use it (actually implementing OnInit is not mandatory but considered good practice): Implement this interface to execute custom initialization logic after your directive’s data-bound properties have been initialized. ngOnInit is called right after ...