Angular 8 类型 'object' 的错误“[object Object]”。 NgFor 仅支持绑定到 Iterables，例如 Arrays

Question

我是 Angular 8 的新手，我正在使用以下结构从 http get 获取数据，我正在尝试使用 *ngFor 迭代数据。不幸的是，我收到以下错误。

如何修复错误？先感谢您 '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays. 学生模型

export class Student {
    Name: string;
    Sport: string;

}

student.service.ts

    public getData(path: string): Observable<Student[]> {
        return this.http.get<Student[]>(this.mainUrl + path).pipe(
            tap(_ => console.log('fetched data'))
        );
    }

student.component.ts

import { Observable, of } from 'rxjs'; 
import { Student } from 'src/app/models/student';
import { HttpService } from 'src/services/http.service';
import { StudentService } from './student.service';


@Component ({
    selector: 'student',
    templateUrl: 'student.component.html',
    styleUrls: ['student.component.css']
})

export class StudentComponent implements OnInit {
    students: Student[];

    constructor(
        private studentService: StudentService
        ) {
    }

    getStudents(): void {

        let ppp = this.studentService.getData("get_students");
        this.studentService.getData("get_students").subscribe(
            students => { this.students = students }
            // students => {console.log(this.students)}
        );
        console.log(this.students); // prints undefined
    }


    ngOnInit() {
        this.getStudents();

    }   
}

student.component.html

<li *ngFor="let p of students">

  <div>hello</div>
</li>

Answer 1

您的服务器响应是一个对象，您需要从中检索服务器响应数据

public getData(path: string): Observable<Student[]> {
  return this.http.get<Student[]>(this.mainUrl + path).pipe(
    map(({ student }) => student)
  );
}

如果您的服务器发送实际数组，如果它仍然抱怨您需要将该响应转换为数组，那应该可以工作。

Angular 8 类型 'object' 的错误“[object Object]”。 NgFor 仅支持绑定到 Iterables，例如 Arrays

Angular 8 error '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays

angular

typescript

angular8