在Angular中,可以使用以下几种方法实现跨组件传值:
利用@Input和@Output装饰器:通过在子组件中使用@Input装饰器接收父组件传递的值,然后通过@Output装饰器将子组件的值传递给父组件。
父组件:
import { Component } from '@angular/core';
@Component({
selector: 'app-parent',
template: `
<h1>Parent Component</h1>
<app-child [childValue]="parentValue" (childEvent)="handleChildEvent($event)"></app-child>
`
})
export class ParentComponent {
parentValue: string;
handleChildEvent(event: string) {
console.log(event);
}
}
子组件:
import { Component, Input, Output, EventEmitter } from '@angular/core';
@Component({
selector: 'app-child',
template: `
<h2>Child Component</h2>
<input [(ngModel)]="childValue" (input)="childEvent.emit(childValue)">
`
})
export class ChildComponent {
@Input() childValue: string;
@Output() childEvent = new EventEmitter<string>();
}
使用服务(Service):创建一个共享的服务,将要传递的值存储在该服务中,然后在需要访问该值的组件中注入该服务。
共享服务:
import { Injectable } from '@angular/core';
@Injectable({
providedIn: 'root'
})
export class SharedService {
sharedValue: string;
}
组件1:
import { Component } from '@angular/core';
import { SharedService } from './shared.service';
@Component({
selector: 'app-component1',
template: `
<h1>Component 1</h1>
<input [(ngModel)]="sharedService.sharedValue">
`
})
export class Component1Component {
constructor(public sharedService: SharedService) {}
}
组件2:
import { Component } from '@angular/core';
import { SharedService } from './shared.service';
@Component({
selector: 'app-component2',
template: `
<h2>Component 2</h2>
<p>{{ sharedService.sharedValue }}</p>
`
})
export class Component2Component {
constructor(public sharedService: SharedService) {}
}
使用路由参数:通过在URL中传递参数,不同组件之间可以通过路由参数进行通信。
路由配置:
import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { Component1Component } from './component1.component';
import { Component2Component } from './component2.component';
const routes: Routes = [
{ path: 'component1/:value', component: Component1Component },
{ path: 'component2/:value', component: Component2Component },
];
@NgModule({
imports: [RouterModule.forRoot(routes)],
exports: [RouterModule]
})
export class AppRoutingModule { }
组件1:
import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
@Component({
selector: 'app-component1',
template: `
<h1>Component 1</h1>
<p>Value: {{ value }}</p>
`
})
export class Component1Component implements OnInit {
value: string;
constructor(private route: ActivatedRoute) {}
ngOnInit() {
this.route.params.subscribe(params => {
this.value = params['value'];
});
}
}
组件2:
import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
@Component({
selector: 'app-component2',
template: `
<h2>Component 2</h2>
<p>Value: {{ value }}</p>
`
})
export class Component2Component implements OnInit {
value: string;
constructor(private route: ActivatedRoute) {}
ngOnInit() {
this.route.params.subscribe(params => {
this.value = params['value'];
});
}
}
这些方法都可以实现跨组件传值,具体选择哪种方法