如何使用角度5发布帖子请求

我想使用angular 5进行post resquest,但它给了我一个错误：这是代码：

service.ts

import { Injectable } from '@angular/core';
import { Response,Headers } from '@angular/http';
import { HttpClient,HttpErrorResponse } from '@angular/common/http';
import { ErrorObservable } from 'rxjs/observable/ErrorObservable';
import { catchError,retry } from 'rxjs/operators';
//Grab everything with import 'rxjs/Rx';
import { Observable } from 'rxjs/Observable';
import { Observer } from 'rxjs/Observer';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';

import { User } from '../iterface';

import { HttpHeaders } from '@angular/common/http';

const httpOptions = {
   headers: new HttpHeaders({
    'Content-Type': 'application/json','Authorization': 'my-auth-token'
   })
};

@Injectable()
export class DataService {

_baseUrl: string = '';

constructor(private http: HttpClient) {
    this._baseUrl = "http://sso-app-bonita.qualif.dauphine.fr:8080/bonita/";
}

addUser(user: User): Observable<User> {
    return this.http.post<User>(this._baseUrl,'/API/identity/user',httpOptions)
        .pipe(
        catchError(this.handleError('addHero',user))
        );
}


private handleError(error: HttpErrorResponse) {
    if (error.error instanceof ErrorEvent) {
        // A client-side or network error occurred. Handle it accordingly.
        console.error('An error occurred:',error.error.message);
    } else {
        // The backend returned an unsuccessful response code.
        // The response body may contain clues as to what went wrong,console.error(
            `Backend returned code ${error.status},` +
            `body was: ${error.error}`);
    }
    // return an ErrorObservable with a user-facing error message
    return new ErrorObservable(
        'Something bad happened; please try again later.');
};

}

component.ts

heroes :[];

createUser() {
  this.dataService.addUser(this.user2)
  .subscribe(hero => this.heroes.push(hero));
}

它给了我一个错误：

TypeError: this.selector is not a function
Stack trace:
CatchSubscriber.prototype.error@webpack-internal:///../../../../rxjs/_esm5/operators/catchError.js:108:26

解决方法

尝试在service.ts中使用它

import {Headers} from 'angular2/http';
var headers = new Headers();
headers.append(headerName,value);

addUser(user : User){
    return this.http.post(this._baseUrl + '/API/identity/user',user,{ headers: headers}).map((response: Response) =>{
    console.log (response.json());
    })
}

在这里你需要发送用户界面到HTTP帖子.并映射您的回复.

在ts文件中

createUser(){

 this.dataService.addUser(this.user2).subscribe(data => {alert("Succesfully Added Product details")},Error => {alert("failed while adding product details")})
}