Question

 <p> i have tried all these
     import {Observable,EMPTY,throwError} from 'rxjs' 
     import 'rxjs/add/operator/catch';
   //import 'rxjs/add/operator/map' 
   //import 'rxjs/Rx' 
    //import {map,catchError} from 'rxjs/operators' 
     import { } from "rxjs/operators";
      import { map, filter, catchError, mergeMap } from 'rxjs/operators'</p>



public isLoggedIn():Observable<boolean>{
  return this.http.get("https://jsonplaceholder.typicode.com/todos/1")
    .pipe(map((res:Response)=> res)
    .catch((error:any)=>Observable.throw(error||'Server Error')))  
}

Answer 1

在RxJS v6中，您列出了pipe()内的运算符逗号分隔

catch现在也称为catchError

尝试以下方法：

public isLoggedIn():Observable<boolean>{
  return this.http.get("https://jsonplaceholder.typicode.com/todos/1").pipe(
    map((res:Response)=> res),
    catchError((error:any)=>Observable.throw(error||'Server Error')))
  )
}

Answer 2

使用function javascript_click() { if (document.getElementById("value3").value && document.getElementById("value4").value) { var attName = document.getElementById("value3").value; var attValue = document.getElementById("value4").value; var value = "[" + attName + "=" + attValue + "]"; var num2 = document.querySelectorAll(value).length; document.getElementById("cnt").innerHTML += "선택하신 노드는 " + num2 + "개 입니다. By javascript<br>"; } else { document.getElementById("cnt").innerHTML += "wrong value of ID <br>"; } }代替<form action=""> <table class="tg" id="tg"> <tr> <td>Attribute name</td> <td><input type="text" id="value3"></td> </tr> <tr> <td>attribute value</td> <td><input type="text" id="value4"></td> </tr> </table> <div id="cnt"></div> </form> <div class="button"> <button id='btn_javascript' onclick="javascript_click();">javascript</button> </div> 并且您必须从CatcError函数返回一个可观察值！

修改后的代码：

catch

类型'OperatorFunction <response，response =“”>'中不存在属性'catch'

2 个答案: