...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

使用管道将数字转换为数组。

@Pipe({
  name: 'enumerate',
})
export class EnumeratePipe implements PipeTransform {
  transform(n: number): number[] {
    return [...Array(n)].map((_,i) => i);
  }
}

然后在模板中使用管道。

<p *ngFor="let i of 5 | enumerate">
   Index: {{ i }}
</p>

https://stackblitz.com/edit/angular-ivy-pkwvyw?file=src/app/app.component.html

其他回答

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));
  }
}

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>

你可以使用lodash:

@Component({
  selector: 'board',
  template: `
<div *ngFor="let i of range">
{{i}}
</div>
`,
  styleUrls: ['./board.component.css']
})
export class AppComponent implements OnInit {
  range = _.range(8);
}

我没有测试代码,但它应该工作。

<div *ngFor="let number of [].constructor(myCollection)">
    <div>
        Hello World
    </div>
</div>

这是一个在myCollection中重复相同次数的好方法。

如果myCollection是5,Hello World会重复5次。

你也可以用like that

export class SampleComponent {
   numbers:Array<any> = [];
   constructor() {
      this.numbers = Array.from({length:10},(v,k)=>k+1);
   }
}

HTML

<p *ngFor="let i of numbers">
   {{i}}
</p>