是什么使用之间的差（@注入（HTTP）的http：HTTP）或不 [英] what is the difference between using (@Inject(Http) http: Http) or not
问题描述
在此<一个href=\"http://stackoverflow.com/questions/35350130/error-using-http-json-angularjs-2/35350172?noredirect=1#35350547\">question,我有新的问题。这两种方式之间的区别是什么？
After this question, I have new a question. What is the difference between these two ways?
这是我最初的code：
This was my initial code:
import {Http, HTTP_PROVIDERS} from 'angular2/http';
@Component({
viewProviders: [HTTP_PROVIDERS],
..//
constructor(http: Http){
..//
但在做测试时，他们提供了codeS查找错误：
but while doing tests, They provided with codes to find the error:
import { Component, Inject} from 'angular2/core';
//above code should be at start.
constructor(@Inject(Http) http: Http) {
我觉得它的工作原理相同无论哪种方式，有人能告诉我，有什么区别，或者只是第一种是像第二个，但 @Inject 是隐性或一些similar.Sorry我的英语水平。
I think it works the same either way, someone could tell me, what is the difference, or just the first one is like the second but @Inject is implicit or something similar.Sorry for my English.
推荐答案
其实， @Inject 装饰器要求某种类型的依赖。字符串还支持在这个水平。
In fact, @Inject decorator is used to ask for a dependency of a certain type. A string is also supported at this level.
如果你已经有了类的如组件或注射一个装饰，并指定在打字稿一个类型参数（你的情况），使用这种装饰等是没有必要的，因为该决议将自动按类。如果你不提供一个类型， @Inject 装饰将是有益的...
If you already have a decorator of the class like Component or Injectable and you specify a type in TypeScript for the parameter (your case), using this other decorator isn't necessary because the resolution will be by class automatically. If you don't provide a type, the @Inject decorator will be useful...
另一个用例。如果你想使用 ngUpgrade （混合Angular1 / Angular2应用），Angular1的工厂只有名字登记的，你不能按类解决这些问题。因此，使用 @Inject 必要在这里。请参阅本plunkr： http://plnkr.co/edit/yMjghOFhFWuY8G1fVIEg?p=$p $ PVIEW 。这是写在打字稿，但没有标注，但可以适应;）
Another use case. If you want to use ngUpgrade (hybrid Angular1 / Angular2 applications), factories of Angular1 are registered by name only and you can't resolve them by class. So using @Inject is necessary here. See this plunkr: http://plnkr.co/edit/yMjghOFhFWuY8G1fVIEg?p=preview. It's written in TypeScript but without annotation but can be adapted ;)
您也可以看看这个链接：
You could also have a look at this link:
- 由Pascal precht注射服务在角2服务 - 的http://blog.thoughtram.io/angular/2015/09/17/resolve-service-dependencies-in-angular-2.html
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