Question

我的意图是在每张幻灯片上更改进度条的宽度。我目前正在使用引导程序提供的进度栏。到目前为止，每张幻灯片我都用HTML调用一个事件。此事件获取有关幻灯片的以下信息：

Console:
{prev: "ngb-slide-0", current: "ngb-slide-1", direction: "left"}

进度条从currentSlide（app.component.ts）获取有关宽度的信息，该方法工作正常：

<div class="progress">
    <div class="progress-bar" role="progressbar" [style.width.%]="currentSlide"></div>
  </div>

到目前为止的打字稿进展：

export class AppComponent {

  public currentSlide: number;

  images = ['assets/images/image1.jpg', 'assets/images/image2.jpg', 'assets/images/image3.jpg'];

  changeProgress(slide: any): void {
    console.log(slide);
  }
}

我的解决之道：

if current: ngb-slide-0 then currentSlide = 33,33
if current: ngb-slide-1 then currentSlide = 66,66 
if current: ngb-slide-2 then currentSlide = 100

如何将这些单词转换为代码？
预先感谢，蒂姆

其余html（滑块示例）：

<div class="container">
  <div class="row">
    <div class="col-12">
      <ngb-carousel *ngIf="images" (slide)="changeProgress($event)">
        <ng-template ngbSlide>
          <img [src]="images[0]" alt="First slide">
        </ng-template>
        <ng-template ngbSlide>
          <img [src]="images[1]" alt="Second slide">
        </ng-template>
        <ng-template ngbSlide>
          <img [src]="images[2]" alt="Third slide">
        </ng-template>
      </ngb-carousel>
    </div>
  </div>
</div>

Answer 1

创建一个保存幻灯片中当前进度百分比的变量，并在触发changeProgress方法并将其绑定到进度条时更改该值，如下所示：

<div class="progress-bar active" role="progressbar" [style.width.%]="currentPercentage"
             [attr.aria-valuenow]="currentPercentage" aria-valuemin="0" aria-valuemax="100">{{this.currentPercentage}}%</div>

在您的组件中，它应该看起来像这样

export class AppComponent {

  public currentSlide: number;
  public currentPercentage: number;

  images = ['assets/images/image1.jpg', 'assets/images/image2.jpg', 'assets/images/image3.jpg'];

  changeProgress(event: any): void {
    this.currentSlide = Number(event.current.substring(10));//10 because you want to remove the string 'ngb-slide-' and get only the selected image
    this.currentPercentage = this.currentSlide / this.images.length * 100;
  }
}

希望这会有所帮助！就像这样，以后您可以在幻灯片中添加更多图像并使用动态代码（我建议您使用ng-For来显示转盘的所有ng模板）

Answer 2

尝试此代码：

// Add the caroussel to you component class, so you can access the slides array
@ViewChild(NgbCarousel) ngbCarousel;

....

changeProgress(slide: any): void {
    // Find the current slide index.
    let slideIndex = this.ngbCarousel.slides._results.findIndex( elem => {
      return elem.id == slide.current;
    });

    // Convert it to a percentage
    this.currentPercentage = (slideIndex + 1) / this.images.length * 100;
}

Angular / ng-bootstrap-使用当前幻灯片更改进度栏

2 个答案: