datas: any = [
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24"},
 ];

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

@Component({
 selector: 'page-array-ngfor',
 templateUrl: 'array-ngfor.html',
})
export class ArrayNgfor {

 constructor() { }

 datas: Array<any> = [
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
  { num: 1, date: "2017-04-12", sellNum: "1231234", sellMpney: "1233", returnNum: "24" },
 ];

 getKeys(item) {
  return Object.keys(item);
 }
}

<ion-header>
 <ion-navbar>
  <ion-title>关于ngfor 嵌套循环</ion-title>
 </ion-navbar>
</ion-header>

<ion-content>
 <ion-row *ngFor="let item of datas">
  <ion-col *ngFor="let key of getKeys(item)"> {{ item[key] }}</ion-col>
 </ion-row>
</ion-content>

 getKeys(item){
    return Object.keys(item);
  }