在Angular 2的for ... of指令中获取索引 [英] Get index in a for...of directive in Angular 2

问题描述

到目前为止，是否有一种方法可以在Angular 2的for..of指令中获取可迭代的当前索引?换句话说，相当于Angular.js v1中的$index ...

As of now, is there a way to get the current index of the iterable in a for..of directive in Angular 2? In others words, the equivalent of $index in Angular.js v1...

代码示例:

<ul *for="#task of allTasks">
    <li>{{ $index}} - {{ task.label }}</li>
</ul>

(当然，此代码不起作用，它不提供当前索引)

(of course this code does not work, it does not provide the current index)

推荐答案

<ul>
    <template ngFor let-task [ngForOf]="allTasks" let-i="index">
        <li>{{ i }} - {{ task.label }}</li>
    </template>
</ul>

但是您必须使用最新版本的快速入门

But you have to use the very most recent version of the quickstart

顺便说一句-以上等同于以下语法糖

BTW - the above is the equivalent of the following syntax sugar

<li *ngFor="let task of allTasks; let i=index">{{ i }} - {{ task.label }}</li>

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