Angular2:如何从父组件到子组件进行通信?

Pin*_*ani 5 routing angularjs angular-ui-router angular

我在标签之间加载了一些div.它如吼叫.

这是我的index.html

<html>
<script>
System.import('app').catch(function(err){ console.error(err); });
</script>
</head>

<!-- 3. Display the application -->

<body>
<my-app>Loading...</my-app>
</body>
</html>
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app.module.ts

@NgModule({
imports: [
    BrowserModule,
    FormsModule,
    AppRoutingModule
],
declarations: [
    AppComponent,
    LoginComponent,
    HomeComponent,
    NewsfeedComponent,
    TopBarComponent,
    SideMenuComponent
],
providers : [
    AuthGaurd
],
bootstrap: [
    AppComponent
] })
export class AppComponent {}
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home.component.ts

@Component({
    selector: 'home',
    moduleId: module.id,
    templateUrl: 'home.component.html',
    providers : [
        LoginService
    ]
})

export class HomeComponent implements OnInit{
isLoggedin : boolean;
constructor (private loginService : LoginService) { }
ngOnInit(): void {
    this.loginService.getLogged().subscribe((isLoggedIn: boolean) => {
        this.isLoggedin = isLoggedIn;
    }); }
}

home.component.html

<side-menu *ngIf='isLoggedin'></side-menu>
<top-bar *ngIf='isLoggedin'></top-bar>
<router-outlet></router-outlet>
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auth.gaurd.ts

@Injectable()
export class AuthGaurd implements CanActivate{
    constructor(private router : Router) {
    }
    canActivate(){
        if (localStorage.getItem('isLogin')){
            return true;
        }
        this.router.navigate(['/login'])
        return false;
    }
}
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login.service.ts

@Injectable()
export class LoginService {
    private subject: Subject<boolean> = new Subject<boolean>();
    constructor(private router : Router) {
    }
    login(){
        this.setLogged(true);
        localStorage.setItem("isLogin","true");
        this.router.navigate(['/news-feed']);
    }
    logout(){
        this.setLogged(false);
        localStorage.removeItem("isLogin");
        this.router.navigate(['/login']);
    }
    getLogged(): Observable<boolean> {
        return this.subject.asObservable();
    }
    setLogged(val : boolean): void {
        this.subject.next(val);
    }
}
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login.component.ts

@Component({
    selector: 'login',
    moduleId: module.id,
    templateUrl: 'login.component.html'
})

export class LoginComponent {
    constructor (private loginService : LoginService) {
    }

    login(){
        this.loginService.login()
    }
}
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login.component.html

<input type="number” #mobileNumber />
<input type="password" #password />
<input type="button" (click)="login()">
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newsfeed.component.ts

@Component({
    selector: 'newsfeed',
    moduleId: module.id,
    templateUrl: 'newsfeed.component.html',
})

export class NewsfeedComponent {

}
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newsfeed.component.html

一些HTML文本.... !!!!

APP-routing.module.ts

@NgModule({
imports: [
    RouterModule.forRoot([
        {
            path : 'login',
            component : LoginComponent
        },
        {
            path : 'news-feed',
            component : NewsfeedComponent,
            canActivate : [AuthGaurd]
        },
        {
            path : '',
            redirectTo : '/news-feed',
            pathMatch : 'full'
        }
        {
            path: '**',
            component: LoginComponent
        }
    ])
],
exports: [
    RouterModule
]
})
export class AppRoutingModule {}
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实际上,当我点击时,它工作正常.就像它的发布完美而不是点击登录按钮它转发到新闻源并显示预期的结果.但是当我从浏览器网址开始时,它不会从home.html加载侧栏和顶栏组件

Gün*_*uer 1

我不确定这是否可以解决所有问题,但我认为您想首先从 localstorage 读取值以获取最近存储的状态,如果您使用侦听器,如果在订阅者订阅之前调用,BehaviorSubject还可以获取最后的状态。this.subject.emit()

@Injectable()
export class LoginService {
    //private subject: Subject<boolean> = new Subject<boolean>(false);
    private subject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(); // <<< changed
    constructor(private router : Router) {
      this.sublect.next(logalStorage.getItem('isLogin')); // <<< added
    }
    login(){
        this.setLogged(true);
        localStorage.setItem("isLogin","true");
        this.router.navigate(['/news-feed']);
    }
    logout(){
        this.setLogged(false);
        localStorage.removeItem("isLogin");
        this.router.navigate(['/login']);
    }
    getLogged(): Observable<boolean> {
        return this.subject.asObservable();
    }
    setLogged(val : boolean): void {
        this.subject.next(val);
    }
}
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