각도 학습에서는 구성 요소 통신 및 구성 요소 수명 주기에 대해 설명합니다.

<app-favorite [isFavorite]="true"></app-favorite>

// favorite.component.ts
import { Input } from '@angular/core';
export class FavoriteComponent {
    @Input() isFavorite: boolean = false;
}

<app-favorite [is-Favorite]="true"></app-favorite>

import { Input } from '@angular/core';

export class FavoriteComponent {
  @Input("is-Favorite") isFavorite: boolean = false
}

<!-- 子组件模板 -->
<button (click)="onClick()">click</button>

// 子组件类
import { EventEmitter, Output } from "@angular/core"

export class FavoriteComponent {
  @Output() change = new EventEmitter()
  onClick() {
    this.change.emit({ name: "张三" })
  }
}

<!-- 父组件模板 -->
<app-favorite (change)="onChange($event)"></app-favorite>

// 父组件类
export class AppComponent {
  onChange(event: { name: string }) {
    console.log(event)
  }
}

export class ChildComponent {
  constructor (private test: TestService) {
    console.log(this.test) // "test"
  }
}

<app-child name="张三"></app-child>

export class ChildComponent implements OnInit {
  @Input("name") name: string = ""
  ngOnInit() {
    console.log(this.name) // "张三"
  }
}

<app-child>
	<div #box>Hello Angular</div>
</app-child>

export class ChildComponent implements AfterContentInit {
  @ContentChild("box") box: ElementRef<HTMLDivElement> | undefined

  ngAfterContentInit() {
    console.log(this.box) // <div>Hello Angular</div>
  }
}

<!-- app-child 组件模板 -->
<p #p>app-child works</p>

export class ChildComponent implements AfterViewInit {
  @ViewChild("p") p: ElementRef<HTMLParagraphElement> | undefined
  ngAfterViewInit () {
    console.log(this.p) // <p>app-child works</p>
  }
}

<app-child [name]="name" [age]="age"></app-child>
<button (click)="change()">change</button>

export class AppComponent {
  name: string = "张三";
  age: number = 20
  change() {
    this.name = "李四"
    this.age = 30
  }
}

export class ChildComponent implements OnChanges {
  @Input("name") name: string = ""
  @Input("age") age: number = 0

  ngOnChanges(changes: SimpleChanges) {
    console.log("基本数据类型值变化可以被检测到")
  }
}

<app-child [person]="person"></app-child>
<button (click)="change()">change</button>

export class AppComponent {
  person = { name: "张三", age: 20 }
  change() {
    this.person = { name: "李四", age: 30 }
  }
}

export class ChildComponent implements OnChanges {
  @Input("person") person = { name: "", age: 0 }

  ngOnChanges(changes: SimpleChanges) {
    console.log("对于引用数据类型, 只能检测到引用地址发生变化, 对象属性变化不能被检测到")
  }
}

export class HomeComponent implements OnDestroy {
  ngOnDestroy() {
    console.log("组件被卸载")
  }
}