Angular2 / http异常没有ConnectionBackend [英] Angular2/http Exception no ConnectionBackend
问题描述
我尝试使用angular2 http请求，但是我收到以下错误：
[错误] EXCEPTION：没有ConnectionBackend的提供程序！ （AppComponent - > Http - > ConnectionBackend）
I attempting to use an angular2 http request, but I am getting the following error: [Error] EXCEPTION: No provider for ConnectionBackend! (AppComponent -> Http -> ConnectionBackend)
我已经设置了一个具有相同问题的准系统应用程序，并且不知道是什么导致它。
I have setup a barebones app which has the same problem, and am at a loss to what is causing it.
提前致谢
app.component.ts
app.component.ts
import {Component} from 'angular2/core';
import {Http, Headers} from 'angular2/http';
@Component({
selector: 'app',
template: `
<button (click)="getEmployee()">Get</button>
<p>{{employee.email}}</p>
`,
providers: [Http]
})
export class AppComponent {
employee: {"email": "bob"};
http: Http;
constructor(http:Http){
this.http = http;
}
getEmployee(){
this.http.get('localhost:8080/employee-rates?id=0')
.map(response => response.json()).subscribe(result => this.employee = result);
}
}
main.ts
import {AppComponent} from './app.component';
import {bootstrap} from 'angular2/platform/browser';
import {HTTP_PROVIDERS, HTTP_BINDINGS} from 'angular2/http';
bootstrap(AppComponent, [
HTTP_PROVIDERS, HTTP_BINDINGS
]);
index.html
index.html
<html>
<head>
<base href="/">
<title>Test</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<script src="js/es6-shim/es6-shim.min.js"></script>
<script src="js/systemjs/dist/system-polyfills.js"></script>
<script src="js/angular2/bundles/angular2-polyfills.js"></script>
<script src="js/systemjs/dist/system.src.js"></script>
<script src="js/rxjs/bundles/Rx.js"></script>
<script src="js/angular2/bundles/angular2.dev.js"></script>
<script src="js/angular2/bundles/http.dev.js"></script>
<!-- 2. Configure SystemJS -->
<script>
System.config({
packages: {
app: {
format: 'register',
defaultExtension: 'js'
}
}
});
System.import('app/main')
.then(null, console.error.bind(console));
</script>
</head>
<!-- 3. Display the application -->
<body>
<div class='small-12'>
<app>Loading...</app>
</div>
</body>
</html>
推荐答案
删除 HTTP_BINDINGS 来自您的代码。它们已被弃用并引用 HTTP_PROVIDERS ，因此就像您使用提供程序两次一样。
Remove HTTP_BINDINGS from your code. They are deprecated and reference HTTP_PROVIDERS, so it's like you're using providers twice.
bootstrap(AppComponent, [HTTP_PROVIDERS]);
此外，您不需要提供商：[Http] 在您的组件中，因为您在bootstrap中注入了 HTTP_PROVIDERS 。将其添加到组件的提供者将创建新的服务实例。
Also you don't need providers: [Http] in your component, since you injected HTTP_PROVIDERS in bootstrap. Adding it to the component's providers will create new instance of the service.
@Component({
providers: []
})
这篇关于Angular2 / http异常没有ConnectionBackend的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
