api - Promise 拒绝 : No provider for UserDetails!(UserDetails 是 Model 类)

Question

我正在尝试获取 session 数据，在 Service-GlobalServiceService 的 GetSessionData() 方法和我的 Component-HeaderComponent 中使用 http get，我正在订阅来自 GetSessionData() 的响应，然后分配给 UserDetails 类型的对象，这是一个模型类(class) 。服务-

import {Observable} from 'rxjs/Rx';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';
import { UserDetails } from "app/model/UserDetails";
@Injectable()
export class GlobalServiceService {
    constructor(private lohttp: Http, private loAuthService : AuthService) { }
GetSessionData(): Observable<UserDetails[]>
{
  return  this.lohttp.get('http://localhost:49609/api/Authentication/checkUserSession')
     .map((res:Response) => res.json()
     .catch((error:any) => Observable.throw(error.json().error ||  'Server 
error'))
     );    
}
}

组件-

import { GlobalServiceService } from './../services/global-service.service';
export class HeaderComponent implements OnInit {
    lsUserName: string;
     lsUserDetails:UserDetails[];
    constructor(private loAuthService: AuthService,private loGlobalService: 
GlobalServiceService,private userDetails:UserDetails) { }
     LoadSessionData()
    {
     this.loGlobalService.GetSessionData()
         .subscribe(
                    data => this.lsUserDetails = data, 
                    err => { console.log(err);}
                    );
    }
 ngOnInit() {
        this.LoadSessionData();
    }
}

我是 Angular 2 的新手。我不明白为什么即使我已经导入它也会显示如下错误:

1.ERROR Error: No provider for UserDetails!
    at injectionError (core.es5.js:1232) [angular]
    ...
View_AppComponent_0 @ AppComponent.html:2
proxyClass @ compiler.es5.js:13560
...
2. zone.js:569 Unhandled Promise rejection: No provider for UserDetails! ; 

3. Zone: <root> ; Task: Promise.then ; Value: Error: No provider for 
UserDetails!
    at injectionError (core.es5.js:1232) [angular]
4.zone.js:571 Error: Uncaught (in promise): Error: No provider for 
UserDetails!

--->当 UserDetails 添加到 app.module.ts 中的 imports 时出现以下错误

Uncaught Error: Unexpected value 'UserDetails' imported by the module 'AppModule'. Please add a @NgModule annotation. at syntaxError (http://localhost:4200/vendor.bundle.js:44937:34) []

Answer 1

由于 UserDetails 是一个模型，您不能将它注入(inject)到构造函数中。

 constructor(private loAuthService: AuthService,private loGlobalService: 
GlobalServiceService,private userDetails:UserDetails)

在 HeaderComponent 中删除这个 -> private userDetails:UserDetails。