从rest api获取json数组对象并尝试在ngfor中显示失败的原因
错误
EXCEPTION:找不到'object'类型的不同支持对象'[object Object]' . NgFor仅支持绑定到诸如Arrays之类的Iterables . 在[HomeComponent @ 5:37中的索引]中
码
import {Component} from 'angular2/core';
import {HomeService} from './home.services';
import {Index} from './index';
@Component({
selector: 'home-app',
providers: [HomeService],
template: `
<section class="left_side">
<article>
<div class="div_home">
<div class="div_homeIndxPartition">
<div class="div_IndxPartition" *ngFor="#indObj of indexes">
<table width="500px" class="idx_cons_table_det">
<tr>
<th align="center" color="#A9F5F2"><h3>{{indObj.name}} ({{indObj.tracker}})</h3></th>
<th align="center">Value</th>
<th align="center">Change</th>
<th align="center">%</th>
</tr>
<tr>
<td align="center" colspan="1"></td>
<td align="center">{{indObj.value}}</td>
<td align="center">{{indObj.change}}</td>
<td align="center">{{indObj.percent}}%</td>
</tr>
</table>
<table width="500px" class="idx_cons_table">
<tr>
<th align="center">High</th>
<th align="center">Low</th>
<th align="center">Open</th>
<th align="center">Close</th>
<th align="center">52 Week High</th>
<th align="center">52 Week Low</th>
</tr>
<tr>
<td align="center">{{indObj.high}}</td>
<td align="center">{{indObj.low}}</td>
<td align="center">{{indObj.open}}%</td>
<td align="center">{{indObj.close}}</td>
<td align="center">{{indObj.yearHigh}}</td>
<td align="center">{{indObj.yearLow}}%</td>
</tr>
</table>
</div>
</div>
</div>
</article>
</section>
`
})
export class HomeComponent {
public indexes:Array<Index>=[];
public error;
constructor(private _service: HomeService){
this.indexes = _service.getIndexes().subscribe(
data => this.indexes = JSON.parse(data),
error => alert(" Error is : " + error),
()=> console.log("finished")
);
console.log(this.indexes);
}
}
JSON数据
[
{
"id": 1,
"name": "FTSE 100",
"ticker": "UKX",
"value": 69875.23,
"change": 100,
"percent": 2.3,
"high": 69875.23,
"low": 69700.89,
"yearHigh": 699999.23,
"yearLow": 680005.23,
"open": 69600.54,
"close": 699000.97,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 2,
"name": "FTSE 250",
"ticker": "MCX",
"value": 465820.85,
"change": 100,
"percent": 2.3,
"high": 465880.12,
"low": 465810.74,
"yearHigh": 478990.34,
"yearLow": 465320.23,
"open": 69600.54,
"close": 699000.97,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 3,
"name": "FTSE All-Share",
"ticker": "ASX",
"value": 236549.23,
"change": 100,
"percent": 2.3,
"high": 236949.23,
"low": 236149,
"yearHigh": 246949.21,
"yearLow": 235549.29,
"open": 236519.23,
"close": 236649.23,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 4,
"name": "Euro Stoxx 50",
"ticker": "STOXX50E",
"value": 123469.87,
"change": 100,
"percent": 2.3,
"high": 123499.87,
"low": 123439.87,
"yearHigh": 123499.87,
"yearLow": 123169.87,
"open": 123465.87,
"close": 123459.87,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 5,
"name": "S&P 500 ",
"ticker": "S500",
"value": 358976.36,
"change": 100,
"percent": 2.3,
"high": 358986.36,
"low": 358946.36,
"yearHigh": 359976.36,
"yearLow": 357976.36,
"open": 358970.36,
"close": 358996.36,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 6,
"name": "Dow Jones I.A.",
"ticker": "INDU",
"value": 456789.36,
"change": 100,
"percent": 2.3,
"high": 456799.36,
"low": 456779.36,
"yearHigh": 456889.36,
"yearLow": 456689.36,
"open": 456729.36,
"close": 456779.36,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 7,
"name": "GOLD",
"ticker": "",
"value": 500,
"change": 100,
"percent": 2.3,
"high": 700,
"low": 300,
"yearHigh": 1500,
"yearLow": 350,
"open": 450,
"close": 470,
"constituents": null,
"runDate": "21/04/2015"
},
{
"id": 8,
"name": "Brent Crude",
"ticker": "",
"value": 112,
"change": 100,
"percent": 2.3,
"high": 115,
"low": 107,
"yearHigh": 200,
"yearLow": 72,
"open": 110,
"close": 115,
"constituents": null,
"runDate": "21/04/2015"
}
]
4 回答
我认为您在
indexes
属性中设置的值不是数组而是对象 .我会看到几个原因:
getIndexes
方法收到响应而不是有效负载 . 在这种情况下,您可以在此方法中使用map
运算符:indexes
属性 .如果要迭代对象的属性,则需要实现如下自定义过滤器:
并使用它:
看到这个问题:
你应该试试这个:
In html:
in .ts file:
我有同样的问题,我的解决方案是没有管道 . 我没有在返回Observer的模板中使用变量,创建中间变量并为其分配结果 . 例如,我们将流保存到
this.sub
但结果将在成功回调时保存为this.indexes
,并将在html模板中使用此变量 .使用Observable时,您不想使用管道 . 这个错误是非常通用的,最好的方法是抛出一个console.log()并查看你出错的地方,因为它可能是很多东西 .
我的问题是我的Array在Object中,我试图遍历Object . 其他问题可能包括映射或ngFor . 我的控制台输出看起来像这样:
所以我需要的修复是这样的:
这是因为数组嵌套在Object中,所以我只是创建了一个新对象并通过获取其属性来访问该数组 .