Question

我使用了Promise和observables逻辑，使用“get”从服务器获取数据。它一直工作到昨天。然后它开始抛出上述错误。请帮我找错。我得到“通用类型'承诺'需要1个类型的参数”错误。

@Injectable()
export class myBlogService{

  // Property to hold root server URL i.e host
  private serverUrl:string = "app/data.json"

  constructor(private http:Http) {}

  // check function in service to check control is coming to service
  check(){
    alert("getting clicked from service");
  }

  // get function to get data from server
  // basically blog datas
  get(): Promise {
    return this.http.get(this.serverUrl)
               .map(response => response.json())
  }
}


/**
 * 
 * My Components
 * 
 */
@Component({
  selector: 'my-app',
  providers: [myBlogService],
  styleUrls: ['app/css/app.css'],
  template: `
    <h1 (click)= check()>My First Angular 2 App</h1>
    <button (click)=get()>Get My Name</button>
    <h1>{{getResponse.name}}</h1>
  `
})
export class myBlogApp {

  // Property to hold blog data
  public getResponse = {"name": "", "age": ""};

  constructor(protected myblogservice:myBlogService){}

  // check function to check control is going to service
  check() {
    this.myblogservice.check();
  }

  // get function calls service get function which return data from server
  get(){
    this.myblogservice.get().subscribe(data => {
      this.getResponse = data;
    });
  }
}


/**
 * 
 * NgModule Declaration
 * 
 */
@NgModule({
  imports:      [ BrowserModule, HttpModule ],
  declarations: [ myBlogApp ],
  providers:    [ ],
  bootstrap:    [ myBlogApp ]
})
export class app{}


/**
 * 
 * App engine entry point
 * 
 */
const platform = platformBrowserDynamic();
platform.bootstrapModule(app);

当给出“承诺：”时，它仍会给出类似的问题 “错误TS2339：'Promise'类型中不存在属性'subscribe'。”

我尝试了不同的解决方案，但没有运气。

Answer 1

您需要添加特定类型。

如果它不包含任何数据且仅用于解析/拒绝功能，请使用：

Promise<void>

最终这是一个类型签名，所以你可以使用：

Promise<any>

https://basarat.gitbooks.io/typescript/content/docs/promise.html

Answer 2

不要使用Promise尝试使用Observable，而是替换：

get(): Promise {
  return this.http.get(this.serverUrl)
               .map(response => response.json())
}

与

get(): Observable<any> {
  return this.http.get(this.serverUrl)
               .map(response => response.json())
}

错误TS2314：泛型类型'Promise <t>'需要1个类型的参数

2 个答案: