在角度 5 中单击时创建按钮微调器

Question

我试图在单击按钮时创建一个微调器，但它似乎没有运行，这就是我在 component.html 中所做的

<button type="submit" class="btn  btn-accent btn-block btn-flat b-r-10" style="background: #FF473A;">
  Sign In
  <i class="fa fa-spinner fa-spin" *ngIf="loading"></i>
</button>

并在 component.ts 中

export class LoginComponent implements onInit {
  private loading: boolean;

  //form ngSubmit function()
  login() {
    if (this.user.email, this.user.password) {
      this.loading = true;
      this.userSrv.login(this.user.email, this.user.password); //api call here
      this.loading = false;
    }
  }
}

好的，我的服务.ts

import { Injectable } from '@angular/core';
import { Http, Headers, RequestOptions } from '@angular/http';
import { Router } from '@angular/router';
import { Globals } from '../shared/api';
import 'rxjs/add/operator/toPromise';
import { Observable } from 'rxjs/Observable';

@Injectable() 导出类 UserService {

private loginUrl = this.globals.LOGIN_URL;
private loggedIn = false;
public loading: boolean = false;


constructor(private http: Http, private router: Router, private globals: Globals) { }

login(email: string, password: string) {
    let headers = new Headers();
    this.loading = true;
    headers.append('Content-Type', 'application/json');
    return this.http.post(this.loginUrl, JSON.stringify({ email, password }), { headers })
        .subscribe(res => {
            let data = res.json();

            if (data.token) {
                this.loading = false;
                window.location.href = '/';
            }
            else {
                this.loading = false;
                this.router.navigateByUrl('/login');
            }

        }, error => {
            this.loading = false;
        })
};

这就是我希望在点击时实现的目标

Answer 1

HttpModule已弃用，HttpClientModule默认情况下您必须使用新的 whcih 将响应格式化为 JSON，因此我们不再需要使用以下方式解析它response.json()：

修改后的服务代码：Observable从您的服务返回并在您的组件中订阅它

    import { Injectable } from '@angular/core';
    import { HttpHeaders,HttpClient } from '@angular/common/http';
    import { Router } from '@angular/router';
    import { Globals } from '../shared/api';

    import { Observable } from 'rxjs/Observable';
    private loginUrl = this.globals.LOGIN_URL;
    private loggedIn = false;
    public loading: boolean = false;


    constructor(private http: HttpClient, private globals: Globals) { }

    login(email: string, password: string):Observable<any> {
       const headers = new HttpHeaders({'Content-Type':'application/json;})

    return this.http.post(this.loginUrl, JSON.stringify({ email, password }), { headers });
}

修订后的组件：
将逻辑放入 subscribe 回调中，以确保微调器仅在您的请求得到解决时才会关闭。

   export class LoginComponent implements onInit {
      constructor(private router:Router){}
      public loading: boolean;

      //form ngSubmit function()
      login() {
        if (this.user.email, this.user.password) {
          this.loading = true;
          this.userSrv.login(this.user.email, this.user.password).subscribe(res 
                => {
            let data = res;

            if (data.token) {
                this.loading = false;
                window.location.href = '/';
            }
            else {
                this.loading = false;
                this.router.navigateByUrl('/login');
            }

        }, error => {
            this.loading = false;
        });
}}

修改后的 HTML

<button type="submit" class="btn  btn-accent btn-block btn-flat b-r-10" (click)="login()" style="background: #FF473A;">
      Sign In
      <i class="fa fa-spinner fa-spin" *ngIf="loading"></i>
    </button>