ngFor，其中索引作为属性中的值 [英] ngFor with index as value in attribute

问题描述

我有一个简单的ngFor循环，该循环也跟踪当前的index.我想将该index值存储在属性中，以便可以打印它.但是我不知道这是如何工作的.

I have a simple ngFor loop which also keeps track of the current index. I want to store that index value in an attribute so I can print it. But I can't figure out how this works.

我基本上有这个:

<ul *ngFor="#item of items; #i = index" data-index="#i">
    <li>{{item}}</li>
</ul>

我想将#i的值存储在属性data-index中.我尝试了几种方法，但没有一个起作用.

I want to store the value of #i in the attribute data-index. I tried several methods but none of them worked.

我在这里有一个演示: http://plnkr.co/edit/EXpOKAEIFlI9QwuRcZqp?p=预览

I have a demo here: http://plnkr.co/edit/EXpOKAEIFlI9QwuRcZqp?p=preview

如何在data-index属性中存储index值?

推荐答案

我将使用以下语法将索引值设置为HTML元素的属性:

I would use this syntax to set the index value into an attribute of the HTML element:

您必须使用let声明值，而不是#.

You have to use let to declare the value rather than #.

<ul>
    <li *ngFor="let item of items; let i = index" [attr.data-index]="i">
        {{item}}
    </li>
</ul>

角度= 1

<ul>
    <li *ngFor="#item of items; #i = index" [attr.data-index]="i">
        {{item}}
    </li>
</ul>

以下是更新的插件: http://plnkr.co/edit/LiCeyKGUapS5JKkRWnUJ?p=预览.

这篇关于ngFor，其中索引作为属性中的值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！