...例如……

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

有可能做一些像……

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

...不诉诸于不优雅的解决方案,比如:

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

?


当前回答

这也可以像这样实现:

HTML:

<div *ngFor="let item of fakeArray(10)">
     ...
</div>

打字稿:

fakeArray(length: number): Array<any> {
  if (length >= 0) {
    return new Array(length);
  }
}

演示工作

其他回答

My-component.ts

numbers: number[] = [];

constructor() {
  this.numbers = new Array<number>(10)
}

My-component.html

<div *ngFor="let num of numbers; let i = index">{{ i }}</div>

我用Angular 5.2.6和TypeScript 2.6.2解决了这个问题:

class Range implements Iterable<number> {
    constructor(
        public readonly low: number,
        public readonly high: number,
        public readonly step: number = 1
    ) {
    }

    *[Symbol.iterator]() {
        for (let x = this.low; x <= this.high; x += this.step) {
            yield x;
        }
    }
}

function range(low: number, high: number) {
    return new Range(low, high);
}

它可以像这样在组件中使用:

@Component({
    template: `<div *ngFor="let i of r">{{ i }}</div>`
})
class RangeTestComponent {
    public r = range(10, 20);
}

为了简洁,故意省略错误检查和断言(例如,如果step为负会发生什么)。

这是我试过的最简单的方法

你也可以在你的组件文件中创建一个数组,你可以用*ngFor指令调用它,返回一个数组。

就像这样....

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-morning',
  templateUrl: './morning.component.html',
  styleUrls: ['./morning.component.css']
})
export class MorningComponent implements OnInit {

  arr = [];
  i: number = 0;
  arra() {
    for (this.i = 0; this.i < 20; this.i++) {
      this.arr[this.i]=this.i;
    }
    return this.arr;
  }

  constructor() { }

  ngOnInit() {
  }

}

这个函数可以在你的html模板文件中使用

<p *ngFor="let a of arra(); let i= index">
value:{{a}} position:{{i}}
</p>

下面是Angular的一些非常干净和简单的东西:

在.ts:

max = 10;    

. html:

<div *ngFor="let dummy of ','.repeat(max).split(','); index as ix">
   - {{ix + 1}}:
</div>

使用自定义结构指令索引:

根据Angular文档:

createEmbeddedView Instantiates an embedded view and inserts it into this container. abstract createEmbeddedView(templateRef: TemplateRef, context?: C, index?: number): EmbeddedViewRef. Param Type Description templateRef TemplateRef the HTML template that defines the view. context C optional. Default is undefined. index number the 0-based index at which to insert the new view into this container. If not specified, appends the new view as the last entry.

当angular通过调用createEmbeddedView创建模板时,它也可以传递将在ng-template中使用的上下文。

使用context可选参数,你可以在组件中使用它, 在模板中提取它,就像你使用*ngFor一样。

app.component.html:

<p *for="number; let i=index; let c=length; let f=first; let l=last; let e=even; let o=odd">
  item : {{i}} / {{c}}
  <b>
    {{f ? "First,": ""}}
    {{l? "Last,": ""}}
    {{e? "Even." : ""}}
    {{o? "Odd." : ""}}
  </b>
</p>

for.directive.ts:

import { Directive, Input, TemplateRef, ViewContainerRef } from '@angular/core';

class Context {
  constructor(public index: number, public length: number) { }
  get even(): boolean { return this.index % 2 === 0; }
  get odd(): boolean { return this.index % 2 === 1; }
  get first(): boolean { return this.index === 0; }
  get last(): boolean { return this.index === this.length - 1; }
}

@Directive({
  selector: '[for]'
})
export class ForDirective {
  constructor(private templateRef: TemplateRef<any>, private viewContainer: ViewContainerRef) { }

  @Input('for') set loop(num: number) {
    for (var i = 0; i < num; i++)
      this.viewContainer.createEmbeddedView(this.templateRef, new Context(i, num));
  }
}