Angular 5：我的回复不会覆盖默认 属性

Question

我尝试在 html 视图中绑定数据，但我的响应不会覆盖默认 属性 值。从 API 我得到了很好的回应。

feedback.statistics.model.ts

export class FeedbackStatistics {
  overall: number = 0;
  technicalSkills: number = 0;
  communication: number = 0;
  commercial: number = 0;
  leadership: number = 0;
}

reviews.component.ts

export class ReviewsComponent implements OnInit {

  message = '';

  feedback: FeedbackStatistics = new FeedbackStatistics();

  constructor(
    private profileService: ProfileService
  ) { }

  ngOnInit(): void {

    this.profileService.getUserFeedbackStatistics().subscribe(
        response => {
            this.feedback = response;
        },
        error => {
            this.message = error.error_description;
        }
    );
  }
}

reviews.component.html

<!-- User Skills -->
<div class="d-flex flex-wrap text-center g-brd-around g-brd-gray-light-v4 g-pa-20 g-mb-40">
  <div class="g-mr-40 g-mb-20 g-mb-0--xl" style="margin-left: 17px;">
    <app-counter [from]=0 [to]=feedback.overall [of]=10 [animationTime]="700" [circleColor]="'#d3b6c6'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Overall</h4>
  </div>

  <div class="g-mr-40 g-mb-20 g-mb-0--xl">
    <app-counter [from]=0 [to]=feedback.technicalSkills [of]=10 [animationTime]="700" [circleColor]="'#bee3f7'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Technical Skills</h4>
  </div>

  <div class="g-mr-40 g-mb-20 g-mb-0--xl">
    <app-counter [from]=0 [to]=feedback.communication [of]=10 [animationTime]="700" [circleColor]="'#ffc2bb'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Communication</h4>
  </div>

  <div class="g-mr-40 g-mb-20 g-mb-0--xl">
    <app-counter [from]=0 [to]=feedback.commercial [of]=10 [animationTime]="700" [circleColor]="'#c9ff97'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Commercial Acumen</h4>
  </div>

  <div class="g-mb-20 g-mb-0--lg">
    <app-counter [from]=0 [to]=feedback.leadership [of]=10 [animationTime]="700" [circleColor]="'#eeeeee'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Leadership</h4>
  </div>
</div> <!-- End User Skills -->

profile.service.ts

    getUserFeedbackStatistics(): Observable<FeedbackStatistics> {
    if (!JSON.parse(localStorage.getItem('authorizationData'))) {
        return Observable.empty<FeedbackStatistics>();
    }

    return this.http.get<FeedbackStatistics>('api/reviews/feedbackStatistics?username=' + JSON.parse(localStorage.getItem('authorizationData')).userName)
    .catch(error => this.handleError(error));
}

例如，如果我按照代码中的说明保留它，我会得到所有 属性 的结果 0，但是如果我这样声明："feedback: FeedbackStatistics;" 我得到响应值但比我有反馈不能取消定义的错误。

欢迎提出任何建议。

谢谢。

Answer 1

一，构造函数没有显式定义这没关系，我猜

第二，如果在订阅之前未在 angular 服务中完成，则需要将响应映射到 json。

第三，

 feedback: FeedbackStatistics = new FeedbackStatistics();

  constructor(private profileService: ProfileService) {
feedback= new FeedbackStatistics();
 }

这需要在构造函数中

Answer 2

我认为在最外层 div 添加一个 *ngIf="feedback" 应该可以解决反馈不能未定义的问题，如下所示： reviews.component.ts

export class ReviewsComponent implements OnInit {

  message = '';

  feedback: FeedbackStatistics;

  constructor(
    private profileService: ProfileService
  ) { }

  ngOnInit(): void {

    this.profileService.getUserFeedbackStatistics().subscribe(
        response => {
            this.feedback = response;
        },
        error => {
            this.message = error.error_description;
        }
    );
  }
}

reviews.component.html

<!-- User Skills -->
<div *ngIf="feedback" class="d-flex flex-wrap text-center g-brd-around g-brd-gray-light-v4 g-pa-20 g-mb-40">
  <div class="g-mr-40 g-mb-20 g-mb-0--xl" style="margin-left: 17px;">
    <app-counter [from]=0 [to]=feedback.overall [of]=10 [animationTime]="700" [circleColor]="'#d3b6c6'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Overall</h4>
  </div>

  <div class="g-mr-40 g-mb-20 g-mb-0--xl">
    <app-counter [from]=0 [to]=feedback.technicalSkills [of]=10 [animationTime]="700" [circleColor]="'#bee3f7'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Technical Skills</h4>
  </div>

  <div class="g-mr-40 g-mb-20 g-mb-0--xl">
    <app-counter [from]=0 [to]=feedback.communication [of]=10 [animationTime]="700" [circleColor]="'#ffc2bb'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Communication</h4>
  </div>

  <div class="g-mr-40 g-mb-20 g-mb-0--xl">
    <app-counter [from]=0 [to]=feedback.commercial [of]=10 [animationTime]="700" [circleColor]="'#c9ff97'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Commercial Acumen</h4>
  </div>

  <div class="g-mb-20 g-mb-0--lg">
    <app-counter [from]=0 [to]=feedback.leadership [of]=10 [animationTime]="700" [circleColor]="'#eeeeee'" [fontSize]="80"></app-counter>
    <h4 class="h6 g-font-weight-300 g-mt-5 mb-0">Leadership</h4>
  </div>
</div> <!-- End User Skills -->

另外，我认为您不应该为 FeedbackStatistics 使用 class，因为您没有添加任何方法。您可以使用这样的界面：

feedback.statistics.model.ts

export interface FeedbackStatistics {
  overall: number;
  technicalSkills: number;
  communication: number;
  commercial: number;
  leadership: number;
}