angular - 如何在angular 5的ngOnInit上调用NgbCarousel的pause()函数

Question

我是 Angular 的新手，我的用户界面使用 ngbootstrap。默认情况下，我无法在暂停模式下加载 NgbCarousel。下面是我试过的代码

    import { Component, OnInit, ViewChild } from '@angular/core';
    import { NgbCarousel } from '@ng-bootstrap/ng-bootstrap';
    @Component({
      selector: 'app-dashboard',
      templateUrl: './dashboard.component.html',
      styleUrls: ['./dashboard.component.css'],
      providers: [NgbCarousel] // add NgbCarouselConfig to the component providers

    })
     export class DashboardComponent implements OnInit {

    constructor(private auth: AuthService, private ngbCarousel: NgbCarousel) {}
    ngOnInit() {
        this.ngbCarousel.pause();
    }
    }

下面是html文件:

<div class="jumbotron">
  <div class="container">
    <div class="row">
      <div class="col-12 col-lg-9">
        <ngb-carousel>
          <ng-template ngbSlide>
            <img src="https://lorempixel.com/900/500?r=1" alt="Random first slide">
            <div class="carousel-caption">
              <h3>First slide label</h3>
              <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
            </div>
          </ng-template>
          <ng-template ngbSlide>
            <img src="https://lorempixel.com/900/500?r=2" alt="Random second slide">
            <div class="carousel-caption">
              <h3>Second slide label</h3>
              <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
            </div>
          </ng-template>
          <ng-template ngbSlide>
            <img src="https://lorempixel.com/900/500?r=3" alt="Random third slide">
            <div class="carousel-caption">
              <h3>Third slide label</h3>
              <p>Praesent commodo cursus magna, vel scelerisque nisl consectetur.</p>
            </div>
          </ng-template>
        </ngb-carousel>
      </div>
    </div>
  </div>
</div>

但是暂停不起作用，我没有收到任何错误。这是调用暂停方法的正确方法吗？请指导我。

Answer 1

编辑:请使用 AfterViewInit生命周期 Hook ，因为此 Hook 在组件的 View 初始化后 被调用(有关更多信息，请参阅 Angular 的 lifecycle hooks documentation):

import { AfterViewInit, ViewChild } from '@angular/core';
// ...
export class DashboardComponent implements AfterViewInit {
  @ViewChild('carousel') carousel: NgbCarousel;
  ngAfterViewInit() {
    this.carousel.pause();
  }
}

---

1. 删除 NgbCarousel作为您组件的提供者，因为根据 docs , NgbCarousel是一个组件并且不是一个服务:

   @Component({
     selector: 'app-dashboard',
     templateUrl: './dashboard.component.html',
     styleUrls: ['./dashboard.component.css']
     // Remove providers array
   })
   

2. 在 <ngb-carousel> 上添加模板引用元素并使用 ViewChild使用模板引用作为选择器，然后调用 pause在 ViewChild 上实例:

   <ngb-carousel #carousel>
     <!-- ... -->
   </ngb-carousel>
   

   import { AfterViewInit, /* OnInit */, ViewChild } from '@angular/core';
   // ...
   export class DashboardComponent implements AfterViewInit {
     @ViewChild('carousel') carousel: NgbCarousel;
     ngAfterViewInit() {
       this.carousel.pause();
     }
   }