[英]Angular 2 - What is a DI error?
I'm having an error when I import a service, but I have no idea why 我导入服务时出错,但我不明白为什么
import { CDService } from "../../services/definition";
constructor(
private toastyCommunicationService: ToastyCommunicationService,
private CDService : CDService,
private SharedService: SharedService,
private DatePipe: DatePipe
) { }
I have made my service litteraly empty because I was so frustrated with the error and not knowing what was causing it. 我让我的服务很空洞,因为我对错误感到非常沮丧,不知道是什么导致了它。
export class CDService {
}
Now I receive the error 现在我收到了错误
EXCEPTION: Uncaught (in promise): Error: DI Error
Error: DI Error
I have 2 questions: 我有两个问题:
1) What the hell is a DI error? 1) DI错误到底是什么?
2) How can I solve this error? 2)我该如何解决这个错误?
It is dependency injection error. 这是依赖注入错误。 I think you are missing @Injectable() decorator: 我认为你缺少@Injectable()装饰器:
@Injectable() // this line
export class CDService {
}
Edit: 编辑:
Have you added CDService into NgModule? 你有没有将CDService添加到NgModule中?
确保将此服务添加到模块的providers
Make sure your service is injectable by using @Injectable()
. 使用@Injectable()
确保您的服务是可@Injectable()
。 This way angular understands its not only a typesscript class but its a angular service. 这种方式角度不仅可以理解它的类型脚本,还可以理解它的角度服务。
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