Angular2中嵌套的ngFor循环的计数器

Question

我在Angular2中有两个嵌套的*ngFor循环.我想维护一个计数器,每次重复循环中心的代码时,计数器会递增.

计数器应从0到调整次数乘以刀片数量

  <tr *ngFor="let adjustment of adjustments">

    <td *ngFor="let blade of blades">

      <span> Counter =  ?????????  </span>

    </td>

  </tr>

Answer 1

将计数器变量添加到两个*ngFor语句,比如说i和j,然后将数学作为表达式.这是代码:

  <tr *ngFor="let adjustment of adjustments; let i = index">

    <td *ngFor="let blade of blades; let j = index">

      <span> Counter = {{ (i * blades.length) + j }} </span>

    </td>

  </tr>