Question

我正在构建一个Angular2应用，但我的文件没有正确编译。

发现了一些类似的问题，但没有解决方案对我有用。

我在控制台中收到错误：

(index):19 Error: (SystemJS) ReleasesComponent is not defined
ReferenceError: ReleasesComponent is not defined
    at eval (http://localhost:3000/app/app.component.js:21:26)
    at Object.eval (http://localhost:3000/app/app.component.js:27:2)
    at eval (http://localhost:3000/app/app.component.js:30:4)
    at eval (http://localhost:3000/app/app.component.js:31:3)
    at eval (<anonymous>)
    at Object.eval (http://localhost:3000/app/app.module.js:15:23)
    at eval (http://localhost:3000/app/app.module.js:48:4)
    at eval (http://localhost:3000/app/app.module.js:49:3)
    at eval (<anonymous>)
Evaluating http://localhost:3000/app/app.component.js
Evaluating http://localhost:3000/app/app.module.js
Evaluating http://localhost:3000/app/main.js
Error loading http://localhost:3000/app/main.js
    at eval (http://localhost:3000/app/app.component.js:21:26)
    at Object.eval (http://localhost:3000/app/app.component.js:27:2)
    at eval (http://localhost:3000/app/app.component.js:30:4)
    at eval (http://localhost:3000/app/app.component.js:31:3)
    at eval (<anonymous>)
    at Object.eval (http://localhost:3000/app/app.module.js:15:23)
    at eval (http://localhost:3000/app/app.module.js:48:4)
    at eval (http://localhost:3000/app/app.module.js:49:3)
    at eval (<anonymous>)
Evaluating http://localhost:3000/app/app.component.js
Evaluating http://localhost:3000/app/app.module.js
Evaluating http://localhost:3000/app/main.js
Error loading http://localhost:3000/app/main.js

app.module.ts

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpModule, JsonpModule } from '@angular/http';

import { AppComponent }  from './app.component';
import { HomeComponent } from './home/home.component';
import { ReleasesComponent } from './releases/releases.component';
import { DistroComponent } from './distro/distro.component';
import { ContactsComponent } from './contacts/contacts.component';
import { routing } from './app.routes';


@NgModule({
  imports:      [ 
    BrowserModule,
    FormsModule,
    HttpModule,
    JsonpModule,
    routing
  ],

  declarations: [ 
    AppComponent,
    HomeComponent,
    ReleasesComponent,
  DistroComponent,
    ContactsComponent
  ],

   bootstrap: [ AppComponent ]
 }) 
export class AppModule { }

releases.component.ts

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'releases',
  templateUrl: 'app/releases/releases.component.html',
  providers: [ReleasesService]
})

export class ReleasesComponent implements OnInit {
 releases: Observable<Array<string>>;

constructor(private releasesService: ReleasesService) { 
}

ngOnInit() { 
  this.releases = this.releasesService.getReleases();
 }
}

tsconfig.json

{
"compilerOptions": {
"target": "es5",
"module": "commonjs",
"moduleResolution": "node",
"sourceMap": true,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"lib": [ "es2015", "dom" ],
"noImplicitAny": true,
"suppressImplicitAnyIndexErrors": true
 }
}

的index.html

<!DOCTYPE html>
<html>
<head>
<base href="/">
<title>PR PR PR</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="app/assets/flex.css">
<link rel="stylesheet" href="app/assets/styles.css">

<!-- Polyfill(s) for older browsers -->
<script src="node_modules/core-js/client/shim.min.js"></script>

<script src="node_modules/zone.js/dist/zone.js"></script>
<script src="node_modules/systemjs/dist/system.src.js"></script>

<script src="systemjs.config.js"></script>
<script>
  System.import('app').catch(function(err){ console.error(err); });
</script>
</head>

<body>
<my-app>Loading AppComponent content here ...</my-app>
</body>
</html>

app.component.ts

import { Component } from '@angular/core';
import { Http } from '@angular/http';
import { ReleasesComponent } from './releases/releases.component';
import { ReleasesService } from './releases/releases.service';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  directives: [ReleasesComponent],
  providers: [Http, ReleasesService]
})
export class AppComponent  { name = 'My name'; }

文件夹结构

Answer 1

路径名称错误。请看下面的代码。

import { Component } from '@angular/core';
import { Http } from '@angular/http';
//modified the below lines
import { ReleasesComponent } from './app/releases/releases.component';
import { ReleasesService } from './app/releases/releases.service';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  directives: [ReleasesComponent],
  providers: [Http, ReleasesService]
})
export class AppComponent  { name = 'My name'; }

在需要 ReleasesComponent 和 ReleasesService 的所有导入语句中也替换这些。

或者，您也可以使用

import { ReleasesComponent } from './../app/releases/releases.component';
import { ReleasesService } from './../app/releases/releases.service';

Answer 2

似乎缺少NgModule参考。在app.module.ts中导入NgModule和FormModue

import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';

Angular2组件未定义

2 个答案: