Question

完整错误消息：

“ 类型'Observable'不能分配给类型'DataListeItem []'。类型“可观察”中缺少属性“包含”。”

我正在使用材料表示意图，现在我想从Rest服务中填充列表。 data-liste-datasource.ts

import { DataSource } from '@angular/cdk/collections';
import { MatPaginator, MatSort } from '@angular/material';
import { map } from 'rxjs/operators';
import { Observable, of as observableOf, merge } from 'rxjs';
import { AuthService } from '../auth.service';


export interface DataListeItem {
  name: string;
  id: number;
  email: string;
  number: number;
}

export class DataListeDataSource extends DataSource<DataListeItem> {
  data: DataListeItem[] = this.authservice.GetUser(); <-- error here!

  constructor(private paginator: MatPaginator, private sort: MatSort, private authservice: AuthService) {
    super();
  }


  connect(): Observable<DataListeItem[]> {

    const dataMutations = [
      observableOf(this.data),
      this.paginator.page,
      this.sort.sortChange
    ];


    this.paginator.length = this.data.length;

    return merge(...dataMutations).pipe(map(() => {
      return this.getPagedData(this.getSortedData([...this.data]));
    }));
  }

  disconnect() { }

  private getPagedData(data: DataListeItem[]) {
    const startIndex = this.paginator.pageIndex * this.paginator.pageSize;
    return data.splice(startIndex, this.paginator.pageSize);
  }

  private getSortedData(data: DataListeItem[]) {
    if (!this.sort.active || this.sort.direction === '') {
      return data;
    }

    return data.sort((a, b) => {
      const isAsc = this.sort.direction === 'asc';
      switch (this.sort.active) {
        case 'name': return compare(a.name, b.name, isAsc);
        case 'email': return compare(a.email, b.email, isAsc);
        case 'id': return compare(+a.id, +b.id, isAsc);
        case 'number': return compare(+a.number, +b.number, isAsc);
        default: return 0;
      }
    });
  }
}
function compare(a, b, isAsc) {
  return (a < b ? -1 : 1) * (isAsc ? 1 : -1);
}

auth.service.ts

import { Injectable } from '@angular/core';
import { HttpHeaders, HttpClient } from '../../node_modules/@angular/common/http';
import { Observable } from '../../node_modules/rxjs';
import { DataListeItem } from './data-liste/data-liste-datasource';

@Injectable({
  providedIn: 'root'
})
export class AuthService {

  constructor(private http: HttpClient) { }

  GetUser(): Observable<DataListeItem[]> {
    return this.http.get<DataListeItem[]>("DataListeItem.online");
  }

因此，所有有关如何调用REST并显示列表的方法。我应该直接在“ data-liste-datasource.ts”中进行呼叫还是应该在服务中。

感谢阅读

Answer 1

您需要使用Observable<DataListeItem[]>代替DataListeItem []。

data: Observable<DataListeItem[]> = this.authservice.GetUser();

类型“ Observable <datalisteitem []>”不可分配给类型“ DataListeItem []”

1 个答案: