不从休息获取数据 Angular 6

Question

我正在尝试从其余 api 获取数据，如下所示，

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

@Component({
  selector: 'app-broker-ui',
  templateUrl: './broker-ui.component.html',
  styleUrls: ['./broker-ui.component.css']
})
export class BrokerUIComponent implements OnInit {

  constructor(private _http:HttpClient) {

   }

  ngOnInit() {
    this.load_broker_list();
  }

  load_broker_list(){
   return this._http.get("http://localhost:8080/broker/all")
                     .subscribe(
                      (data:any[]) => {
                       console.log(data);
                      }
                     )

  }

}

但它没有 console.log 数据，这里是示例数据

[ 
  { id: 1, username: "AAA" }, 
  { id: 2, username: "BBB" }, 
  { id: 3, username: "CCC" }, 
  { id: 4, username: "DDD" }, 
  { id: 5, username: "EEE" } 
]

这是我遇到的错误，

Error: StaticInjectorError(AppModule)[BrokerUIComponent -> HttpClient]: StaticInjectorError(Platform: core)[BrokerUIComponent -> HttpClient]: NullInjectorError: No provider for HttpClient!

Answer 1

HttpClient class 未在 DI 中找到。您需要将 HttpClientModule 添加到 AppModule 的导入中。

例子

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

@NgModule({
   imports: [
      ...
      HttpClientModule
      ...
   ]
})
export class AppModule { }

Answer 2

在您的应用程序中使用任何 HTTP 服务之前，您需要将 HttpClientModule 导入 app-module.ts（主模块），就像这样 -

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

@NgModule({
   imports: [
     HttpClientModule
     // OtersModules
      ...
   ]
})
export class AppModule { 
 }

不从休息获取数据 Angular 6

Does not getting data from rest Angular 6

javascript

rest

angular

angular6