Angular 2 bootstrap函数给出错误“参数类型AppComponent不能分配给参数类型Type”。 [英] Angular 2 bootstrap function gives error "Argument type AppComponent is not assignable to parameter type Type"

问题描述

这是我的第一个简单的 Hello World 来自

查看 bootstrap 函数声明， AppComponent 需要扩展类型。

  export declare function bootstrap（appComponentType：Type，customProviders？：Array< any>）：Promise< ComponentRef> ;; 
  

我的问题是：

Angular组件是否应该延长类型？

解决方案

实际上， AppComponent应该扩展Type 。因此，请使用以下内容：

  // app.component.ts 
从'@ angular2导入{Component，Type} /核心'; 
 
 @Component（{
 ... 
 ... 
}）
导出类AppComponent扩展类型{} 
  

这也将遵循针对AppComponent（要进行自举）的ng2的预期约定。

我不确定为什么他们没有在ng2教程中介绍它，可能他们的目标是简化初始学习，因为即使没有 extends 部分，它也会运行。

这在WebStorm / IntelliJ中完全正常。

编辑：替代解决方案是更新到Webstorm v2016.2（在评论时这是稳定的）。

Here is my first simple Hello World angular 2 app from Angular 2 quick start guide.

import {Component} from 'angular2/core';
import {bootstrap} from 'angular2/platform/browser';
@Component({
    selector: 'ng2-app',
    template: '<h1>My first Angular 2 App</h1>'
})
export class AppComponent { }


bootstrap(AppComponent);

The application runs fine when I run with npm start but my IntelliJ IDE is showing error in the line with bootstrap(AppComponent)

Argument type AppComponent is not assignable to parameter type Type

Looking at the bootstrap function declaration, AppComponent needs to extends Type.

export declare function bootstrap(appComponentType: Type, customProviders?: Array<any>): Promise<ComponentRef>;

My question is:

Is it expected for Angular components to extend Type?

解决方案

Actually, AppComponent is expected to extend Type. So use the following:

// app.component.ts
import { Component, Type } from '@angular2/core';

@Component({
...
...
})
export class AppComponent extends Type {}

This will also follow the expected convention by ng2 for AppComponent (to be bootstrapped).

I am not sure why they didn't cover it in the ng2 tutorials, probably they might be targeting to simplify the initial learning, as it runs even without the extends part.

This works perfectly fine in WebStorm/IntelliJ.

Edit: Alternate solution is to update to Webstorm v2016.2 (which is stable at the time of this comment).

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