Angular 2 - NgFor 使用数字代替集合 [英] Angular 2 - NgFor using numbers instead collections

问题描述

...例如...

...

可以做类似...

...

...没有诉诸非优雅的解决方案，例如:

<div class="month" *ngFor="#item of ['dummy','dummy','dummy','dummy','dummy','dummy','dummy','dummy'];#i = 索引">...

?

解决方案

在你的组件中，你可以定义一个数字数组 (ES6)，如下所述:

导出类 SampleComponent {构造函数(){this.numbers = Array(5).fill().map((x,i)=>i);//[0,1,2,3,4]this.numbers = Array(5).fill(4);//[4,4,4,4,4]}}

请参阅此链接以创建数组:在 JavaScript 中从 1..20 创建整数数组的最简单方法.

然后你可以用 ngFor 遍历这个数组:

@Component({模板:`<ul><li *ngFor="let number of numbers">{{number}}</li>`})导出类 SampleComponent {(...)}

或者很快:

@Component({模板:`<ul><li *ngFor="let number of [0,1,2,3,4]">{{number}}</li>`})导出类 SampleComponent {(...)}

...for example...

<div class="month" *ngFor="#item of myCollection; #i = index">
...
</div>

Is possible to do something like...

<div class="month" *ngFor="#item of 10; #i = index">
...
</div>

...without appeal to a non elegant solution like:

<div class="month" *ngFor="#item of ['dummy','dummy','dummy','dummy','dummy',
'dummy','dummy','dummy']; #i = index">
...
</div>

?

解决方案

Within your component, you can define an array of number (ES6) as described below:

export class SampleComponent {
  constructor() {
    this.numbers = Array(5).fill().map((x,i)=>i); // [0,1,2,3,4]
    this.numbers = Array(5).fill(4); // [4,4,4,4,4]
  }
}

See this link for the array creation: Tersest way to create an array of integers from 1..20 in JavaScript.

You can then iterate over this array with ngFor:

@Component({
  template: `
    <ul>
      <li *ngFor="let number of numbers">{{number}}</li>
    </ul>
  `
})
export class SampleComponent {
  (...)
}

Or shortly:

@Component({
  template: `
    <ul>
      <li *ngFor="let number of [0,1,2,3,4]">{{number}}</li>
    </ul>
  `
})
export class SampleComponent {
  (...)
}

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