从rest api获取json数组对象并尝试在ngfor中显示失败，原因为
例外：找不到不同的支持对象＆＃39; [object Object]＆＃39;类型＆＃39;对象＆＃39;。 NgFor仅支持绑定到诸如Arrays之类的Iterables。在[HomeComponent @ 5:37中的索引]中
代码
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>
<br/>
<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);
}
}
[
{
"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"
}
]
答案 0 :(得分：9)
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：
您从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：
getIndexes() {
return this.http.get(...).map(res => res.json());
}
收到的有效负载与数组不对应，但与某些属性相对应。在这种情况下，您需要将此属性设置为indexes属性。
如果要迭代对象的属性，则需要实现这样的自定义过滤器：
@Pipe({name: 'keyValues'})
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;
}
}
并使用它：
<div class="div_IndxPartition" *ngFor="#indObj of indexes | keyValues">
(...)
</div>
看到这个问题：
答案 1 :(得分：1)
你应该试试这个：
在html中：
<div *ngFor="let subsciption of subscriptions;">
<div class="col-md-6">
<h5 class="widget-title">{{subsciption.name}}</h5>
</div>
</div>
：
export class SubscriptionComponent implements OnInit {
private subscriptions: any =[];
// private subscriptions: any ={}; // here dont use {}
.
.
.
.
.
getAllSubscriptions(queryString) {
this._http.get(`${environment.base_url}/subscriptions` + queryString)
.subscribe((response: Response) => {
this.subscriptions = response.json();
},
(error: Response) => {
console.log("Login error");
});
}
this.getAllSubscriptions(query);
}
答案 2 :(得分：0)
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到this.indexes，并将在html模板中使用此变量。
@Component({
template: `
<ul>
<li *ngFor="let index of indexs">
{{ index }}
</li>
</ul>
`
})
export class HomeComponent {
privat sub;
public indexes:Array<Index>=[];
public error;
constructor(private _service: HomeService) {
this.sub = this._service.getIndexes().subscribe(
data => this.indexes = JSON.parse(data),
error => alert(" Error is : " + error),
() => console.log("finished")
);
}
}
答案 3 :(得分：0)
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：
upcomingEvents所以我需要的修复是这样的：
this.indexes = _service.getIndexes()
.subscribe(
data => {
this.indexes = JSON.parse(data);
console.log(indexes);
},
error => alert(" Error is : " + error),
()=> console.log("finished")
);
console.log(this.indexes);
这是因为数组嵌套在Object中，所以我只创建了一个新对象并通过获取其属性来访问该数组。
答案 4 :(得分：0)
我看到了答案，简单的解决方法是将* ngFor对象的类型设置为如下数组：
public indexes:Array<TYPE_OF_YOUR_DATA>=[];