Question

我的后端使用ASP.NET Core而前端使用Angular。我有一个api，它从后端给我作为json的数据。

我创建了一个加载api-data的服务，但它只是返回＆＃39; undefined＆＃39;。

employee.service.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Http } from '@angular/http';

import { Observable } from 'rxjs/Rx';
import { of } from 'rxjs/observable/of';
import { catchError, map, tap } from 'rxjs/operators';
import 'rxjs/add/operator/map';
import 'rxjs/Rx';

import { Employee } from './employee';

//interface Employee_interface {
//    id: number;
//    name: string;
//}

@Injectable()
export class EmployeeService {

    constructor(public http: HttpClient, private _httpService: Http) {}

    //apiEmployees: JSON;
    employees: Employee[];
    stuff: Object;

    getEmployees(): Observable<Employee[]> {

        this.http.get('/api/employees').subscribe(data => { console.log(data); }); //I can see an array with my json-data from the api
        this.http.get('/api/employees').subscribe(data => this.stuff = data);
        console.log("LOG: " + this.stuff); //LOG: undefined
        console.log("LOG1 :" + this.http.get('/api/employees').pipe()); //LOG1 :[object Object]

        return this.http.get('/api/employees').pipe();
    }
}

我有什么要回来的？

app.components.ts

import { Component, OnInit } from '@angular/core';
import { Http } from '@angular/http';
import { HttpClient } from '@angular/common/http';

import { Employee } from './employee';
import { EmployeeService } from './employee.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit{
    title = 'app';
    employees: Employee[];

    constructor(public http: HttpClient, private _httpService: Http, private employeeService: EmployeeService) { }

    ngOnInit() {
        this.getEmployees();
    }

    getEmployees(): void {
        this.employeeService.getEmployees()
            .subscribe(employees => this.employees = employees);
    }
}

有人能帮帮我吗？先谢谢你！

Answer 1

改变这个：

return this.http.get('/api/employees').pipe();

进入这个：

return this.http.get('/api/employees')
    .map(response => response.json())
    .catch((error: any) => Observable.throw(
        { message: error.json().message, details: error.json().details }));

这里我们处理错误（首先要弄清楚出了什么问题，如果出错了）我们正在将响应解析为JSON。

希望它有用。

使用Angular从web api控制器返回json

1 个答案: