Question

我试图将多选添加到this guide之后的Angular Material表中。它在masterToggle中引用了data，但是我的UserDataSource中没有该属性。解决此问题的正确方法是什么？

我的组件

dataSource: UserDataSource;

ngOnInit() {
    this.dataSource = new UserDataSource(this.svc);
    this.dataSource.loadCompanies(this.lgid);
}
masterToggle() {
    this.isAllSelected() ?
        this.selection.clear() :
        this.dataSource.data.forEach(row => this.selection.select(row));
}

用户数据源：

export class UserDataSource implements DataSource<Company> {

private CompanyModelsSubject = new BehaviorSubject<Company[]>([]);
private loadingSubject = new BehaviorSubject<boolean>(false);
public loading$ = this.loadingSubject.asObservable();

constructor(private svc: GreencardService) { }

connect(collectionViewer: CollectionViewer): Observable<Company[]> {
    return this.CompanyModelsSubject.asObservable();
}

disconnect(collectionViewer: CollectionViewer): void {
    this.CompanyModelsSubject.complete();
    this.loadingSubject.complete();
}

loadCompanies(lgid)
{
    this.loadingSubject.next(true);
    this.svc.getCompanies(lgid).pipe(
        catchError(() => of([])),
        finalize(() => this.loadingSubject.next(false))
    ).subscribe(x => { this.CompanyModelsSubject.next(x);});
}

Answer 1

我相信您所遵循的示例正在使用MatTableDataSource类，该类具有公共获取器data ...

get data() { return this._data.value; }

私有变量_data是带有初始化数据的BehaviorSubject。

 constructor(initialData: T[] = []) {
    super();
    this._data = new BehaviorSubject<T[]>(initialData);
    this._updateChangeSubscription();
  }

由于创建了自己的类，因此您将需要实现一个类似的公共获取器……可能如下所示。

get data() {return this.CompanyModelsSubject.value; }

https://github.com/angular/material2/blob/bc8fc75bf8af82378077d7c2277e31a1dcd6aac9/src/lib/table/table-data-source.ts#L62

UserDataSource在Angular中没有数据属性

1 个答案: