可观察和HTTP JSON Angular的麻烦

Question

我有问题，因为我从不在 * nfor中绘制变量" datos"，我认为问题在于渲染，因此，它实现"可观察到"，但是它仍然不起作用

感谢您的帮助！

" header-menu.component.ts"

import { Component, Input, OnInit, ChangeDetectionStrategy } from '@angular/core';
    import { Http } from '@angular/http';
    import 'rxjs/add/operator/map';
    import 'rxjs/add/operator/catch';
    import { Observable } from 'rxjs/Observable';
    @Component({
        moduleId: module.id,
        selector: 'as-headermenu',
        templateUrl: 'header-menu.html',
        changeDetection: ChangeDetectionStrategy.OnPush
    })
    export class HeaderMenuComponent implements OnInit {
    datos = []; // Aqui se carga el json
    private ruta = 'assets/json_header_menu.json';  
    constructor(private http: Http) {}
    ngOnInit() {
         this.loadJson().subscribe(
                    vdatos => this.datos = vdatos,
                    err => console.log(err),
        () => console.log(this.datos));
        console.log(this.datos);
    }
loadJson(): Observable<any[]> {
          return this.http.get(this.ruta)
            .map(res => res.json());
}
}

" header-menu.html"

<ul *ngIf="datos"> <li *ngFor="let dato of datos | async; let i =
index"> {{ dato.url }} {{ dato.icono }} {{ dato.titulo }} {{ i }} 
</li> 

" header-menu-module.ts"

import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import { BrowserModule } from '@angular/platform-browser';
import { HttpModule } from '@angular/http';
import { HeaderMenuComponent } from './index';
@NgModule({
    declarations: [
        HeaderMenuComponent
    ],
    imports: [
        RouterModule,
        BrowserModule,
        HttpModule
    ],
    exports: [
        HeaderMenuComponent
    ]
})
export class HeaderMenuModule {
}

图像控制台错误：控制台错误

Answer 1

您不需要在这里的异步管，它应该没有它，

<ul *ngIf="datos"> <li *ngFor="let dato of datos; let i =
index"> {{ dato.url }} {{ dato.icono }} {{ dato.titulo }} {{ i }} 
</li> 

Answer 2

| async管道确实有助于从Observable流中解开数据。因此，要使您的代码工作，您应该分配可观察到的datos变量。

ngOnInit() {
    this.datos = this.loadJson();
}

Answer 3

我修复了它以删除代码"更改"

的行

 @Component({
        moduleId: module.id,
        selector: 'as-headermenu',
        templateUrl: 'header-menu.html',
        /*changeDetection: ChangeDetectionStrategy.OnPush*/
    })

谢谢