Question

我试图在angular2-counto循环中使用*ngFor指令我知道每个实例都需要一个唯一的字符串。所以

<div 
    counto
    [step]="30"
    [countTo]="myArr[0].Amount"
    [countFrom]="0"
    [duration]="2"
    (countoChange)="counto_0 = $event"
    (countoEnd)="onCountoEnd()">
      {{counto_0 | number:'1.0-0'}}
  </div>
  <div 
    counto
    [step]="30"
    [countTo]="myArr[1].Amount"
    [countFrom]="0"
    [duration]="2"
    (countoChange)="counto_1 = $event"
    (countoEnd)="onCountoEnd()">
      {{counto_1 | number:'1.0-0'}}
</div>
...

应该成为

<div *ngFor="let item of myArr"
    counto
    [step]="30"
    [countTo]="item.Amount"
    [countFrom]="0"
    [duration]="2"
    (countoChange)="??? = $event"
    (countoEnd)="onCountoEnd()">
      {{??? | number:'1.0-0'}}
  </div>

但是我可以在???中使用什么作为循环每次迭代的唯一参数？ counto指令需要一个字符串参数（我认为）。尝试使用*ngFor=let i item of myArr; let i = index;然后以某种方式使用指令中的索引不起作用。

<div *ngFor="let item of myArr; let i = index;"
    counto
    [step]="30"
    [countTo]="item.Amount"
    [countFrom]="0"
    [duration]="2"
    (countoChange)="i = $event"
    (countoEnd)="onCountoEnd()">
      {{i | number:'1.0-0'}}
  </div>

Uncaught Error: Cannot assign to a reference or variable!

中的结果

Answer 1

您正尝试将$event分配给i变量。尝试类似：

newVar[i] = $event

angular2-counto里面* ngFor

1 个答案: