如何在ngFor循环外得到索引

Question

angular2，使得下方的p标签随着上方slider的变化而变化

    <div class="slider">
        <ul class="slides">
            <li *ngFor="let uploadedPhoto of uploadedPhotos;let idx=index">
                <img [src]="uploadedPhoto.photo">

            </li>
        </ul>
    </div>

    <p class="light grey-text text-darken-3 center-align ">{{uploadedPhotos[0].caption}}</p>//如何得到idx

Answer 1

<div class="slider">
    <ul class="slides">
        <li *ngFor="let uploadedPhoto of uploadedPhotos;let idx=index">
            <img [src]="uploadedPhoto.photo">
            <p class="light grey-text text-darken-3 center-align ">{{uploadedPhoto.caption}}</p>
        </li>
    </ul>
</div>

这样每个图片下边都有一个p标签