组件间三种典型关系:
父好组件之间的交互(@Input/@Output/模板变量/@ViewChild)
非父子组件之间的交互(Service/localStorage)
还可以可以利用 Session、 路由参数来进行通讯等
相关教学推荐:《angular教学》
父子组件之间交互
子组件编写
child.component.ts
@Component({ selector: 'app-child', templateUrl: './child.component.html', styleUrls: ['./child.component.css']})export class ChildComponent implements OnInit { private _childTitle = '我是子组件'; @Input() set childTitle(childTitle: string) { this._childTitle = childTitle; } get childTitle(): string { return this._childTitle; } @Output() messageEvent: EventEmitter = new EventEmitter(); constructor() { } ngOnInit(): void { } sendMessage(): void { this.messageEvent.emit('我是子组件'); } childFunction(): void { console.log('子组件的名字是:' + this.childTitle); }}
child.component.html
{{childTitle}}
父组件
parent-and-child.component.ts
@Component({ selector: 'app-parent-and-child', templateUrl: './parent-and-child.component.html', styleUrls: ['./parent-and-child.component.css']})export class ParentAndChildComponent implements OnInit { constructor() { } ngOnInit(): void { } doSomething(event: any): void { alert(event); }}
parent-and-child.component.html
父组件
@Input 属性绑定是单向的,父组件的属性变化会影响子组件的属性变化, 子组件的属性变化不会反过来影响父组件的的属性变化。
不过,可以利用 @Input() 和 @Output() 实现属性的双向绑定。
@Input()value: string;@Output()valueChange: EventEmitter = new EventEmitter();// 实现双向绑定
注意: 使用 [()]
进行双向绑定时,输出属性名必须是输入属性名与 Change 组成, 形如: xxxChange。
非父子组件之间交互
使用 Service 进行交互
event-bus.service.ts
/** * 用于充当事件总线 */@Injectable()export class EventBusService { evnetBus: Subject = new Subject(); constructor() { }}
child1.component.ts
@Component({ selector: 'app-child1', templateUrl: './child1.component.html', styleUrls: ['./child1.component.css']})export class Child1Component implements OnInit { constructor(private eventBusService: EventBusService) { } ngOnInit(): void { } triggerEventBus(): void { this.eventBusService.evnetBus.next('child1 触发的事件'); }}
child1.component.html
child1 组件
child2.component.ts
@Component({ selector: 'app-child2', templateUrl: './child2.component.html', styleUrls: ['./child2.component.css']})export class Child2Component implements OnInit { events: Array = new Array(); constructor(private eventBusService: EventBusService) { } ngOnInit(): void { this.listenerEvent(); } listenerEvent(): void { this.eventBusService.evnetBus.subscribe( value => { this.events.push(value); }); }}
child2.component.html
child2 组件{{event}}
brother.component.ts
@Component({ selector: 'app-brother', templateUrl: './brother.component.html', styleUrls: ['./brother.component.css']})export class BrotherComponent implements OnInit { constructor() { } ngOnInit(): void { }}
brother.component.html
第二种:没有父子关系的组件间通讯
使用 localStorage 进行交互
local-child1.component.ts
@Component({ selector: 'app-local-child1', templateUrl: './local-child1.component.html', styleUrls: ['./local-child1.component.css']})export class LocalChild1Component implements OnInit { constructor() { } ngOnInit(): void { } writeData(): void { window.localStorage.setItem('message', JSON.stringify({name: 'star', age: 22})); }}
local-child1.component.html
LocalChild1 组件
local-child2.component.ts
@Component({ selector: 'app-local-child2', templateUrl: './local-child2.component.html', styleUrls: ['./local-child2.component.css']})export class LocalChild2Component implements OnInit { constructor() { } ngOnInit(): void { } readData(): void { const dataStr = window.localStorage.getItem('message'); const data = JSON.parse(dataStr); console.log('name:' + data.name, 'age:' + data.age); }}
local-child2.component.html
LocalChild2 组件
local-storage.component.ts
@Component({ selector: 'app-local-storage', templateUrl: './local-storage.component.html', styleUrls: ['./local-storage.component.css']})export class LocalStorageComponent implements OnInit { constructor() { } ngOnInit(): void { }}
local-storage.component.html
第三种方案:利用 localStorge 通讯
最后,关于使用 Session、路由参数实现数据交互的方式,这里就不演示了。
编程视频!!