角2提供（）与ES5中的字符串？

Question

我正在尝试使用String作为提供而不是类的标记：

app.RandomComponent = ng.core
    .Component({
        selector: "randomComponent",
        template: "Component!",
        providers: [
            ng.core.provide("Stuff", {useValue: "Hello"})
        ]
    })
    .Class({
        constructor: ["Stuff", function(stuff) {

        }]
    });

但是，它引发错误： EXCEPTION: Cannot resolve all parameters for 'class5'(Stuff). Make sure that all the parameters are decorated with Inject or have valid type annotations and that 'class5' is decorated with Injectable. EXCEPTION: Cannot resolve all parameters for 'class5'(Stuff). Make sure that all the parameters are decorated with Inject or have valid type annotations and that 'class5' is decorated with Injectable.

根据https://angular.io/docs/ts/latest/api/core/Provider-class.html，它应该至少在TS中起作用：/

Answer 1

根据Inject文档 。

当@Inject（）不存在时，Injector将使用参数的类型注释。

在您的情况下，您要注入一个简单的字符串，但是angular2不能将字符串用作您的Stuff类型。 因此，在这些情况下，您必须使用ng.core.Inject ，如下所示

.Class({

    // Note the ng.core.Inject
    constructor: [ng.core.Inject("Stuff"), function(stuff) {
      console.log(stuff);
    }]
});

这是您的代码正常工作的plnkr 。