Question

我正在尝试使用bootstrap 4轮播作为角度5的内容滑块。

我想做一个* ngFor和活动轮播项目，显示4 * ngFor结果。

这是我到目前为止。

<div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
    <ol class="carousel-indicators">
      <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
      <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
      <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
    </ol>
    <div class="carousel-inner" role="listbox">
        <div class="carousel-item active">
          <div class="row mar-30">
          <div  class=" col-md-3" 
          *ngFor="let blog of blogs | async; let i = index"
          >
          <div *ngIf="i<4">
              <app-blogcard
              (checked)="OnChecked($event)"
              [blog]="blog"
              ></app-blogcard>
          </div>
          </div>
          </div>
      </div>

    </div>
    <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
      <span class="carousel-control-prev-icon" aria-hidden="true"></span>
      <span class="sr-only">Previous</span>
    </a>
    <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
      <span class="carousel-control-next-icon" aria-hidden="true"></span>
      <span class="sr-only">Next</span>
    </a>
  </div>

这将显示活动轮播项目的四个项目，因为我的* ngIf限制为4.无论如何，我可以更好地做到这一点，而不必在下一个轮播项目上做另外的* ngFor？

Answer 1

在slice

中使用*ngFor

 <div  class=" col-md-3" 
          *ngFor="let blog of (blogs ? blogs.slice(0,4): []) | async; let i = index"
          >
          <div >
              <app-blogcard
              (checked)="OnChecked($event)"
              [blog]="blog"
              ></app-blogcard>
          </div>

Answer 2

我没有完全解决你的问题，但我“完善了”你的代码。随意看看：

    <div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
  <ol class="carousel-indicators">
    <ng-container *ngFor="let blog of blogs?.slice(0, 4) | async; let i = index">
      <li data-target="#carouselExampleIndicators" data-slide-to="{{i}}"></li>
    </ng-container>
  </ol>
  <div class="carousel-inner" role="listbox">
    <div class="carousel-item active">
      <div class="row mar-30">
        <div class=" col-md-3" *ngFor="let blog of blogs?.slice(0, 4)">
          <app-blogcard (checked)="OnChecked($event)" [blog]="blog"></app-blogcard>
        </div>
      </div>
    </div>
  </div>
  <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="sr-only">Next</span>
  </a>
</div>

如何在bootstrap 4轮播上进行Angular * ngFor

2 个答案: