Angular 材质创建类似于引导警报的警报

我是有角材料的新手。我正在尝试实现警报以使用角度材料显示消息，这与引导警报即类似。

<div class="alert alert-success" role="alert">
  <strong>Well done!</strong> You successfully read this important alert message.
</div>
<div class="alert alert-info" role="alert">
  <strong>Heads up!</strong> This alert needs your attention, but it's not super important.
</div>
<div class="alert alert-warning" role="alert">
  <strong>Warning!</strong> Better check yourself, you're not looking too good.
</div>
<div class="alert alert-danger" role="alert">
  <strong>Oh snap!</strong> Change a few things up and try submitting again.
</div>

谁能帮助我在角度材料中实施的最佳方法是什么？

非常感谢

Angular Materials 没有内置的 Alert 组件，但你可以很容易地实现一个并对其进行自定义，该实现包括一个组件和一个服务，模板和 CSS 文件完成这些组合。

警报组件

import { Component, OnInit, OnDestroy } from '@angular/core';
    import { Subscription } from 'rxjs';
    import { AlertService } from 'src/app/_services';

    @Component({
        selector: 'alert',
        templateUrl: 'alert.component.html',
        styleUrls: ['./alert.component.css']
    })

    export class AlertComponent implements OnInit, OnDestroy {
        private subscription: Subscription;
        message: any;

        constructor(private alertService: AlertService) { }

        ngOnInit() {
            this.subscription = this.alertService.getMessage().subscribe(message => { 
                this.message = message; 
            });
        }

        ngOnDestroy() {
            this.subscription.unsubscribe();
        }
    }

警报模板

<div *ngIf="message" [ngClass]="{ 'alert': message, 'alert-success': message.type === 'success', 'alert-danger': message.type === 'error' }">{{message.text}}</div>

警报方式

.alert-danger {
    background-color: #f44336; /* Red */
}
.alert-success {
    background-color: #36f456;  
} 
.alert{
    padding: 20px;
    color: white;
    margin-bottom: 15px;
    text-align: center;
}

警报服务

import { Injectable } from '@angular/core';
import { Router, NavigationStart } from '@angular/router';
import { Observable, Subject } from 'rxjs';

@Injectable()
export class AlertService {
    private subject = new Subject<any>();
    private keepAfterNavigationChange = false;

    constructor(private router: Router) {
        // clear alert message on route change
        this.router.events.subscribe(event => {
            if (event instanceof NavigationStart) {
                if (this.keepAfterNavigationChange) {
                    // only keep for a single location change
                    this.keepAfterNavigationChange = false;
                } else {
                    // clear alert
                    this.subject.next();
                }
            }
        });
    }

    success(message: string, keepAfterNavigationChange = false) {
        this.keepAfterNavigationChange = keepAfterNavigationChange;
        this.subject.next({ type: 'success', text: message });
    }

    error(message: string, keepAfterNavigationChange = false) {
        this.keepAfterNavigationChange = keepAfterNavigationChange;
        this.subject.next({ type: 'error', text: message });
    }

    getMessage(): Observable<any> {
        return this.subject.asObservable();
    }
}

典型用途

this.alertService.error("Error!! Something went wrong");
this.alertService.success("Success, You are done");

登录失败时显示警报的用法示例

onSubmit(){
      this.authService.login(this.user).subscribe(

        (res: any) => {
          if(!res.hasError && res.token){
            this.authService.isLoggedIn = true;
            localStorage.setItem('token', res.token); 
            this.router.navigate(['/']);
          } else {
            this.alertService.error(res.errorMessage);
          }

        },
        err => {
          this.alertService.error(err.errorMessage);
        }
      );     
    }