我想为Angular 8添加一个答案:

对于循环，你可以做:

<ng-container *ngFor="let item of BATCH_FILE_HEADERS | keyvalue: keepOriginalOrder">
   <th nxHeaderCell>{{'upload.bulk.headings.'+item.key |translate}}</th>
</ng-container>

同样，如果你需要上面的数组来保持原始的顺序，那么在你的类中声明这个:

public keepOriginalOrder = (a, b) => a.key;

你可以使用keyvalue管道作为示例代码提供:

    <div style="flex-direction: column">
        <app-cart-item
            class="cart-item"
            *ngFor="let keyValuePair of this.allProductRecords | keyvalue"
            [productRecord]="keyValuePair.value"
            (removeProduct)="removeProductFromCart(keyValuePair.key)"
        ></app-cart-item>
        <br />
        <p style="font-family: Verdana, Geneva, Tahoma, sans-serif; font-weight: bolder">
            Total ${{ getTotalPurchaseAmount() }}
        </p>
    </div>

谢谢管道，但我必须做一些改变之前，我可以在angular 2 RC5使用它。更改了管道导入行，并在键数组初始化中添加了any类型。

 import {Pipe, PipeTransform} from '@angular/core';

 @Pipe({name: 'keys'})
 export class KeysPipe implements PipeTransform {
 transform(value) {
   let keys:any = [];
   for (let key in value) {
      keys.push( {key: key, value: value[key]} );
    }
     return keys;
  }
}

ECMA 2017+解决方案

遵循一些其他答案的思想，您可以创建一个Pipe来从您的对象创建一个[key, value]数组，但是以一种更简单的方式，遵循新的方法object。在ECMA 2017中引入的条目。

Pipe

import { PipeTransform, Pipe } from '@angular/core';

/**
 * Transform a literal object into array
 */
@Pipe({
  name: 'forObject',
  pure: true,
})
export class ForObjectPipe implements PipeTransform {

  transform(object, args?: any): any {
    return Object.entries(object);
  }
}

模块

在模块中，声明并提供它

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';

import { ForObjectPipe } from './for-object.pipe';

import { MyPageRoutingModule } from './my-routing.module';
import { MyPage } from './my.page';

@NgModule({
  imports: [
    CommonModule,
    MyPageRoutingModule,
  ],
  declarations: [
    MyPage,
    ForObjectPipe,
  ],
  providers: [
    ForObjectPipe,
  ]
})
export class MyPageModule {}

然后你可以在你的组件中使用typescript代码或HTML。

组件中使用

// ...
import { ForObjectPipe } from './for-object.pipe';

@Component({
  selector: 'app-my',
  templateUrl: './my.page.html',
  styleUrls: ['./my.page.scss'],
})
export class MyComponent {
  obj: { [key: any]: any } = {
    1: 'hello',
    2: 'world',
  };

  constructor(private forObjectPipe: ForObjectPipe) { }

  foo() {
     const myArray = this.forObjectPipe.transform(this.obj);
     // same as 
     const myArray = Object.entries(this.obj);
  }
}

在组件视图中使用

<h1>Object:</h1>
<div *ngFor="let pair of obj | forObject">
  KEY: {{ pair[0] }} - VALUE: {{ pair[1] }}
</div>

输出:

Object:
KEY: 1 - VALUE: hello
KEY: 2 - VALUE: world

现场演示:https://stackblitz.com/edit/angular-qapapx?file=src/app/hello.component.ts

像这样创建数组

tags = [
        {
            name : 'Aliko Dogara',
            amount   : '60,000',
            purpose: 'Office repairs'
        },
        {
            name : 'Aliko Dogara',
            amount   : '60,000',
            purpose: 'Office repairs'
        },
        {
            name : 'Aliko Dogara',
            amount   : '60,000',
            purpose: 'Office repairs'
        },
        {
            name : 'Aliko Dogara',
            amount   : '60,000',
            purpose: 'Office repairs'
        },
        {
            name : 'Aliko Dogara',
            amount   : '60,000',
            purpose: 'Office repairs'
        }
    ];

一直都有效

您可以创建一个自定义管道来返回每个元素的键列表。 就像这样:

import { PipeTransform, Pipe } from '@angular/core';

@Pipe({name: 'keys'})
export class KeysPipe implements PipeTransform {
  transform(value, args:string[]) : any {
    let keys = [];
    for (let key in value) {
      keys.push(key);
    }
    return keys;
  }
}

像这样使用它:

<tr *ngFor="let c of content">           
  <td *ngFor="let key of c | keys">{{key}}: {{c[key]}}</td>
</tr>

Edit

你也可以返回一个包含键和值的条目:

@Pipe({name: 'keys'})
export class KeysPipe implements PipeTransform {
  transform(value, args:string[]) : any {
    let keys = [];
    for (let key in value) {
      keys.push({key: key, value: value[key]});
    }
    return keys;
  }
}

像这样使用它:

<span *ngFor="let entry of content | keys">           
  Key: {{entry.key}}, value: {{entry.value}}
</span>