Firebase 不返回对象

Question

我正在尝试用 angular 10 中存储在 firebase 中的对象填充表。它在终端中没有显示任何错误，但在编译时显示

错误：找不到“object”类型的不同支持对象“[object Object]”。 NgFor 只支持绑定到 Arrays 等 Iterables。

component.html

<tbody>
    <tr *ngFor="let p of positiveDetails" >
        <td></td>
        <td>{{p.name}}</td>
        <td>{{p.age}}</td>
        <td>{{p.area}}</td>
        <td>
            <a [routerLink]="['positive-details/', p.key]">View</a> 
  // Redirects to another Component where i can View every details (Cannot get ID)
        </td>
    </tr>
</tbody>

component.ts

export class PositiveListComponent {
  positiveDetails: AngularFireList<any>;

  constructor( private db: AngularFireDatabase , private positiveService: PositiveService) {
    this.positiveDetails = this.positiveService.getAll()
   }
}

service.ts

export class PositiveService {

  constructor( private db: AngularFireDatabase ) { }

  create(positiveDetails){
    return this.db.list('/positiveDetails').push(positiveDetails);
  }

  getAll() {
    return this.db.list('/positiveDetails');
  }
}

我不清楚是否必须在某处导入模型

Answer 1

您必须执行以下操作

this.positiveService.getAll().snapshotChanges().pipe(
      map(changes =>
        changes.map((c: any, index: number) => {
          console.log('c is', c);
          return (
            {
              id: index + 1,
              name: c.payload.val().name, //add your objects here
              mobileNo: c.payload.val().mobileno,
            }
          );
        }
        )
      )
    ).subscribe(datas => {
      this.positiveDetails = datas;
    });

或者类似的东西

this.positiveService.getAll().snapshotChanges().pipe(
  map(snapDoc => {
    return snapDoc.map(doc => {
    return {
        id: doc.payload.doc.id,
        ...doc.payload.doc.data()
    };
    });
  });
);