Angular2：呈现JSON时出错

Question

我在获取订阅时收到的JSON数据时遇到错误。给出错误作为未定义的属性。请帮助，因为我提到许多其他类似的没有什么工作对我来说。我附加了控制器，模板和json

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import { Component, OnInit, OnDestroy } from '@angular/core';
import { DetailService } from '../detail.service';
import { Router, ActivatedRoute } from '@angular/router';
import { Subscription } from 'rxjs';

@Component({
  selector: 'app-detail-page',
  templateUrl: './detail-page.component.html',
  styleUrls: ['./detail-page.component.css'],
  providers: [DetailService]
})
export class DetailPageComponent implements OnInit, OnDestroy {
detailData: any;
id:string;
params: any;
private subscription: Subscription;
name: string;
  constructor(private detailService: DetailService, private router: Router, private activatedRoute: ActivatedRoute) { 
    this.params = activatedRoute.params.subscribe(
      params => this.id = params['id']
    );
  }

  ngOnInit() {
        this.detailService.getDetailData()
  .subscribe(
    data => this.detailData = data[this.id]
  );
}  

ngOnDestroy(){
  this.subscription.unsubscribe();
}

}



// ****** JSON ******

[{"id":1,"name":"Leanne Graham","username":"Bret","email":"Sincere@april.biz","address":{"street":"Kulas Light","suite":"Apt. 556","city":"Gwenborough","zipcode":"92998-3874","geo":{"lat":"-37.3159","lng":"81.1496"}},"phone":"1-770-736-8031 x56442","website":"hildegard.org","company":{"name":"Romaguera-Crona","catchPhrase":"Multi-layered client-server neural-net","bs":"harness real-time e-markets"}},{"id":2,"name":"Ervin Howell","username":"Antonette","email":"Shanna@melissa.tv","address":{"street":"Victor Plains","suite":"Suite 879","city":"Wisokyburgh","zipcode":"90566-7771","geo":{"lat":"-43.9509","lng":"-34.4618"}},"phone":"010-692-6593 x09125","website":"anastasia.net","company":{"name":"Deckow-Crist","catchPhrase":"Proactive didactic contingency","bs":"synergize scalable supply-chains"}},{"id":3,"name":"Clementine Bauch","username":"Samantha","email":"Nathan@yesenia.net","address":{"street":"Douglas Extension","suite":"Suite 847","city":"McKenziehaven","zipcode":"59590-4157","geo":{"lat":"-68.6102","lng":"-47.0653"}},"phone":"1-463-123-4447","website":"ramiro.info","company":{"name":"Romaguera-Jacobson","catchPhrase":"Face to face bifurcated interface","bs":"e-enable strategic applications"}},{"id":4,"name":"Patricia Lebsack","username":"Karianne","email":"Julianne.OConner@kory.org","address":{"street":"Hoeger Mall","suite":"Apt. 692","city":"South Elvis","zipcode":"53919-4257","geo":{"lat":"29.4572","lng":"-164.2990"}},"phone":"493-170-9623 x156","website":"kale.biz","company":{"name":"Robel-Corkery","catchPhrase":"Multi-tiered zero tolerance productivity","bs":"transition cutting-edge web services"}},{"id":5,"name":"Chelsey Dietrich","username":"Kamren","email":"Lucio_Hettinger@annie.ca","address":{"street":"Skiles Walks","suite":"Suite 351","city":"Roscoeview","zipcode":"33263","geo":{"lat":"-31.8129","lng":"62.5342"}},"phone":"(254)954-1289","website":"demarco.info","company":{"name":"Keebler LLC","catchPhrase":"User-centric fault-tolerant solution","bs":"revolutionize end-to-end systems"}},{"id":6,"name":"Mrs. Dennis Schulist","username":"Leopoldo_Corkery","email":"Karley_Dach@jasper.info","address":{"street":"Norberto Crossing","suite":"Apt. 950","city":"South Christy","zipcode":"23505-1337","geo":{"lat":"-71.4197","lng":"71.7478"}},"phone":"1-477-935-8478 x6430","website":"ola.org","company":{"name":"Considine-Lockman","catchPhrase":"Synchronised bottom-line interface","bs":"e-enable innovative applications"}},{"id":7,"name":"Kurtis Weissnat","username":"Elwyn.Skiles","email":"Telly.Hoeger@billy.biz","address":{"street":"Rex Trail","suite":"Suite 280","city":"Howemouth","zipcode":"58804-1099","geo":{"lat":"24.8918","lng":"21.8984"}},"phone":"210.067.6132","website":"elvis.io","company":{"name":"Johns Group","catchPhrase":"Configurable multimedia task-force","bs":"generate enterprise e-tailers"}},{"id":8,"name":"Nicholas Runolfsdottir V","username":"Maxime_Nienow","email":"Sherwood@rosamond.me","address":{"street":"Ellsworth Summit","suite":"Suite 729","city":"Aliyaview","zipcode":"45169","geo":{"lat":"-14.3990","lng":"-120.7677"}},"phone":"586.493.6943 x140","website":"jacynthe.com","company":{"name":"Abernathy Group","catchPhrase":"Implemented secondary concept","bs":"e-enable extensible e-tailers"}},{"id":9,"name":"Glenna Reichert","username":"Delphine","email":"Chaim_McDermott@dana.io","address":{"street":"Dayna Park","suite":"Suite 449","city":"Bartholomebury","zipcode":"76495-3109","geo":{"lat":"24.6463","lng":"-168.8889"}},"phone":"(775)976-6794 x41206","website":"conrad.com","company":{"name":"Yost and Sons","catchPhrase":"Switchable contextually-based project","bs":"aggregate real-time technologies"}},{"id":10,"name":"Clementina DuBuque","username":"Moriah.Stanton","email":"Rey.Padberg@karina.biz","address":{"street":"Kattie Turnpike","suite":"Suite 198","city":"Lebsackbury","zipcode":"31428-2261","geo":{"lat":"-38.2386","lng":"57.2232"}},"phone":"024-648-3804","website":"ambrose.net","company":{"name":"Hoeger LLC","catchPhrase":"Centralized empowering task-force","bs":"target end-to-end models"}}]

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<ul class="list-group">
  <li class="list-group-item">Id: {{detailData.id}}</li>
  <li class="list-group-item">Email: {{detailData}}</li>
</ul>

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Answer 1

使用safe / elvis运算符检查数据是否存在并绑定

<ul class="list-group">
  <li class="list-group-item">Id: {{detailData?.id}}</li>
  <li class="list-group-item">Email: {{detailData}}</li>
</ul>