json - 使用 ngFor Angular 打印出 API 结果
问题描述
我正在尝试在我的网络面板中打印 json 响应。当我尝试显示完整响应时,它可以完美运行,但随后我尝试使用 ngFor,我在浏览器中收到了这些错误:
ERROR TypeError: Cannot read property 'getContext' of null
ERROR TypeError: Cannot read property 'result' of undefined
这是我尝试使用的一种方法:
<div *ngFor="let subject of lstresult.result.subject | json " class=" col-lg-4">
<div class=" card card-chart">
<div class=" card-header">
<h5 class=" card-category">Completed Tasks</h5>
<span>{{ subject | json }}</span>
<br /><br />
</div>
<div class=" card-body">
</div>
</div>
</div>
为 API 准备的类如下所示:
export interface VatAPI {
result: EntityResponse;
}
export interface EntityResponse {
subject: Entity[];
requestDateTime: string;
requestId: string;
}
export interface Entity {
authorizedClerks: EntityPerson[];
regon: string;
workingAddress: string;
hasVirtualAccounts: boolean;
statusVat: string;
krs: string;
restorationBasis: string;
accountNumbers: string[];
registrationDenialBasis: string;
representatives: EntityPerson[];
residenceAddress: string;
registrationDenialDate: Date;
restorationDate: Date;
name: string;
registrationLegalDate: Date;
removalBasis: string;
removalDate: Date;
nip: string;
partners: EntityPerson[];
pesel: string;
}
export interface EntityPerson {
firstName: string;
lastName: string;
nip: string;
companyName: string;
}
API 请求如下所示:
export class ApiService {
constructor(private httpclient: HttpClient) {}
getcomments(): Observable<any> {
return this.httpclient.get(
"https://wl-api.mf.gov.pl/api/search/nips/5213003700,6151001756?date=2020-07-27"
);
}
}
对于某些上下文,完整示例响应如下所示:
"result" : { "subjects": [ { "name": "ARTUR PIKOR, EWA PIKOR SKLEP \"MERCEDES\" AUTO SERWIS S.C.", "nip": "6151001756", "statusVat": "Czynny", "regon": "230180142", "pesel": null, "krs": null, "residenceAddress": null, "workingAddress": "LUBAŃSKA 5, 59-903 ZGORZELEC", "representatives": [], "authorizedClerks": [], "partners": [], "registrationLegalDate": "1994-12-29", "registrationDenialBasis": null, "registrationDenialDate": null, "restorationBasis": null, "restorationDate": null, "removalBasis": null, "removalDate": null, "accountNumbers": [ "75109019680000000106202838" ], "hasVirtualAccounts": false }, { "name": "FUNDACJA WIELKA ORKIESTRA ŚWIĄTECZNEJ POMOCY", "nip": "5213003700", "statusVat": "Zwolniony", "regon": "010168068", "pesel": null, "krs": "0000030897", "residenceAddress": null, "workingAddress": "DOMINIKAŃSKA 19C, 02-738 WARSZAWA", "representatives": [], "authorizedClerks": [], "partners": [], "registrationLegalDate": "2004-04-19", "registrationDenialBasis": null, "registrationDenialDate": null, "restorationBasis": null, "restorationDate": null, "removalBasis": null, "removalDate": null, "accountNumbers": [ "79114010100000524444001001", "14114010100000524444001007", "56114010100000524444001027", "29114010100000524444001028", "29124011121111001000177255" ], "hasVirtualAccounts": true } ], "requestDateTime": "08-08-2020 19:25:11", "requestId": "1khm1-88d50kn" }
component.ts 代码:
this.ApiService.getcomments().subscribe((data) => {
this.lstresult = data;
});
也许这是一个初学者的错误,但我无法解决这个问题;)
解决方案
1_ 您的响应已从 API 以 json 格式返回。无需json
管道
2_ngFor 正在尝试访问lstresult
对象内部的数据,但由于数据尚未加载而无法访问。所以使用async
pipe 而不是json
.
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