Observable.map - 提供的参数与调用目标的任何签名不匹配

Question

我有一个角度为2的应用程序。从rxjs-5.0.0-beta.12升级至rxjs-5.1.0，但现在低于this.http.get(...).map()显示错误。

提供的参数不匹配

import { Http, Headers } from '@angular/http'; 
import { Observable } from 'rxjs/Observable'; 
import 'rxjs/add/operator/map'; 
import 'rxjs/add/operator/catch'; 

export class BaseService { 
    private baseUrl: string = 'http://someserver:8080/somedb'; 

    constructor(public http: Http) {} 

    doGet(url: string, headers?: Headers): Observable<any> { 
     if(headers) { 
      return this.http.get(this.baseUrl+url, {headers: headers}).map(response => { 

      }, err => { 

      }); 

     } 
    } 

} 

错误只添加.map()发生时，通话对象的任何签名，确实在释放什么变化？

完整IDE消息：

[ts] Supplied parameters do not match any signature of call target. 
Applies a given project function to each value emitted by the source 
Observable, and emits the resulting values as an Observable. 

<span class="informal">Like Array.prototype.map(), 
it passes each source value through a transformation function to get 
corresponding output values.</span> 

<img src="./img/map.png" width="100%"> 

Similar to the well known Array.prototype.map function, this operator 
applies a projection to each value and emits that projection in the output 
Observable. 

@example <caption>Map every every click to the clientX position of that click</caption> 
var clicks = Rx.Observable.fromEvent(document, 'click'); 
var positions = clicks.map(ev => ev.clientX); 
positions.subscribe(x => console.log(x)); 

@see {@link mapTo} 
@see {@link pluck} 

@return {Observable<R>} An Observable that emits the values from the source 
Observable transformed by the given project function. 
@method map 
@owner Observable 

(property) Observable<Response>.map: <T, R>() => any 

Answer 1

Observable.map只需要一个回调函数作为参数。 你应该把错误回调subscribe()或使用catch

if(headers) { 
      return this.http.get(this.baseUrl+url, {headers: headers}).map(response => { 

      }).catch(err=>{}); 

     }