角度材料表

Question

我学习Angular，并使用调用API来接收数据以填充表。

表中的记录未显示。但使用console.log，我可以在控制台中看到它们。

这是我的组件.ts

export class ListaUtentiComponent implements OnInit {
displayedColumns =  ['id', 'username'];
@Input()
dataSource: MatTableDataSource<any>;
utenti: Utenti [];
@ViewChild(MatPaginator) paginator: MatPaginator;
@ViewChild(MatSort) sort: MatSort;
constructor(public rest: ApiService, private router: Router) { }
ngOnInit(): void {
this.dataSource = new MatTableDataSource();
this.getUser();
this.dataSource.paginator = this.paginator;
this.dataSource.sort = this.sort;
}
getUser() {
this.rest.getUsers().subscribe((data) => {
console.log(data);
alert(data);
this.dataSource['data']; 
return data;

});
}
}

这是我的组件.html

<div class="mat-elevation-z8">
<table mat-table class="full-width-table" matSort aria-label="Elements" [dataSource]="dataSource">

<ng-container matColumnDef="id">
<th mat-header-cell *matHeaderCellDef mat-sort-header>Id</th>
<td mat-cell *matCellDef="let ut">{{ut.id}}</td>
</ng-container>

<ng-container matColumnDef="username">
<th mat-header-cell *matHeaderCellDef mat-sort-header>Nome</th>
<td mat-cell *matCellDef="let ut">{{ut.name}}</td>
</ng-container> 
<tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
<tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
</table>
<mat-paginator #paginator
[length]="dataSource?.data.length"
[pageIndex]="0"
[pageSize]="10"
[pageSizeOptions]="[10, 20]">
</mat-paginator>
</div> 

请帮帮我，我不知道怎么了。

Answer 1

我没有看到任何代码将提取的数据分配给mat表的dataSource。

你要做的是更新数据源，例如：

getUser() {
this.rest.getUsers().subscribe((data) => {
this.dataSource = data;
});
}

Answer 2

import { DataSource } from '@angular/cdk/collections';
import { MatPaginator } from '@angular/material/paginator';
import { MatSort } from '@angular/material/sort';
import { map } from 'rxjs/operators';
import { Observable, of as observableOf, merge } from 'rxjs';
// TODO: Replace this with your own data model type
export interface ListaUtentiItem {
id: string,
email: string,
emailConfirmed: boolean,
passwordHash: string,
securityStamp: string,
phoneNumber: string,
phoneNumberConfirmed: boolean,
twoFactorEnabled: boolean,
lockoutEndDateUtc: string,
lockoutEnabled: boolean,
accessFailedCount: number,
userName:string
}
// TODO: replace this with real data from your application
const EXAMPLE_DATA: ListaUtentiItem[] = [
// {id: 1, name: 'Hydrogen'},
// {id: 2, name: 'Helium'},
// {id: 3, name: 'Lithium'},
// {id: 4, name: 'Beryllium'},
// {id: 5, name: 'Boron'},
// {id: 6, name: 'Carbon'},
// {id: 7, name: 'Nitrogen'},
// {id: 8, name: 'Oxygen'},
// {id: 9, name: 'Fluorine'},
// {id: 10, name: 'Neon'},
// {id: 11, name: 'Sodium'},
// {id: 12, name: 'Magnesium'},
// {id: 13, name: 'Aluminum'},
// {id: 14, name: 'Silicon'},
// {id: 15, name: 'Phosphorus'},
// {id: 16, name: 'Sulfur'},
// {id: 17, name: 'Chlorine'},
// {id: 18, name: 'Argon'},
// {id: 19, name: 'Potassium'},
// {id: '20', userName: 'Calcium',},
];
/**
* Data source for the ListaUtenti view. This class should
* encapsulate all logic for fetching and manipulating the displayed data
* (including sorting, pagination, and filtering).
*/
export class ListaUtentiDataSource extends DataSource<ListaUtentiItem> {
data: ListaUtentiItem[] = EXAMPLE_DATA;
paginator: MatPaginator;
sort: MatSort;
constructor() {
super();
}
/**
* Connect this data source to the table. The table will only update when
* the returned stream emits new items.
* @returns A stream of the items to be rendered.
*/
connect(): Observable<ListaUtentiItem[]> {
// Combine everything that affects the rendered data into one update
// stream for the data-table to consume.
const dataMutations = [
observableOf(this.data),
this.paginator.page,
this.sort.sortChange
];
return merge(...dataMutations).pipe(map(() => {
return this.getPagedData(this.getSortedData([...this.data]));
}));
}
/**
*  Called when the table is being destroyed. Use this function, to clean up
* any open connections or free any held resources that were set up during connect.
*/
disconnect() {}
/**
* Paginate the data (client-side). If you're using server-side pagination,
* this would be replaced by requesting the appropriate data from the server.
*/
private getPagedData(data: ListaUtentiItem[]) {
const startIndex = this.paginator.pageIndex * this.paginator.pageSize;
return data.splice(startIndex, this.paginator.pageSize);
}
/**
* Sort the data (client-side). If you're using server-side sorting,
* this would be replaced by requesting the appropriate data from the server.
*/
private getSortedData(data: ListaUtentiItem[]) {
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 'username': return compare(a.userName, b.userName, isAsc);
case 'id': return compare(+a.id, +b.id, isAsc);
default: return 0;
}
});
}
}
/** Simple sort comparator for example ID/Name columns (for client-side sorting). */
function compare(a: string | number, b: string | number, isAsc: boolean) {
return (a < b ? -1 : 1) * (isAsc ? 1 : -1);
}

这是