“在此html文件中,这是说length属性是未定义的。当我使用 由角度cli生成的硬编码数据,当我使用该数据时,我没有收到error。 其余api响应,那时候我出错了。”
<button type="button" class="btn btn-primary" (click)="OnFetchEmployee()">fetchEmpoyee Web service</button>
<div class="mat-elevation-z8" data-table>
<table mat-table class="full-width-table" matSort aria-label="Elements">
<!-- Id Column -->
<ng-container matColumnDef="id">
<th mat-header-cell *matHeaderCellDef mat-sort-header>Id</th>
<td mat-cell *matCellDef="let row">{{row.id}}</td>
</ng-container>
<!-- Name Column -->
<ng-container matColumnDef="name">
<th mat-header-cell *matHeaderCellDef mat-sort-header>Name</th>
<td mat-cell *matCellDef="let row">{{row.name}}</td>
</ng-container>
<!-- emailId Column -->
<ng-container matColumnDef="emailId">
<th mat-header-cell *matHeaderCellDef mat-sort-header>Email</th>
<td mat-cell *matCellDef="let row">{{row.emailId}}</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]="50"
[pageSizeOptions]="[1,25, 50, 100, 250]">
</mat-paginator>
</div>
“这是我在OnFetchEmployee()中执行其余api调用的数据表组件”
import { AfterViewInit, Component, OnInit, ViewChild, Input } from '@angular/core';
import { MatPaginator } from '@angular/material/paginator';
import { MatSort } from '@angular/material/sort';
import { MatTable } from '@angular/material/table';
import { DataTableDataSource, DataTableItem } from './data-table-datasource';
import { Employee } from '../shared/employee.model';
import { RestCallService } from '../rest-call.service';
@Component({
selector: 'app-data-table',
templateUrl: './data-table.component.html',
styleUrls: ['./data-table.component.css']
})
export class DataTableComponent implements AfterViewInit, OnInit {
@ViewChild(MatPaginator, {static: false}) paginator: MatPaginator;
@ViewChild(MatSort, {static: false}) sort: MatSort;
@ViewChild(MatTable, {static: false}) table: MatTable<DataTableItem>;
dataSource: DataTableDataSource;
constructor(private restCall : RestCallService){}
/** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
displayedColumns = ['id', 'name' ,'emailId'];
Employee :Employee[] =[];
ngOnInit() {
this.dataSource = new DataTableDataSource();
}
ngAfterViewInit() {
this.dataSource.sort = this.sort;
this.dataSource.paginator = this.paginator;
this.table.dataSource = this.dataSource;
}
OnFetchEmployee(){
console.log("onfetchEmployee is called");
this.restCall.fetchEmployee().subscribe(EmpData=> {
console.log("employee Data is :"+EmpData);
this.dataSource.data=EmpData as Employee[];
} ,error=>{
console.log(error);
});; ;
}
}
“这是由角度cli自动生成的数据源表Ts文件”
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';
import { Employee } from '../shared/employee.model';
import { RestCallService } from '../rest-call.service';
// TODO: Replace this with your own data model type
export interface DataTableItem {
id : number;
name : string;
emailId : string;
}
// TODO: replace this with real data from your application
export class DataTableDataSource extends DataSource<DataTableItem> {
data: DataTableItem[];
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<DataTableItem[]> {
// 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: DataTableItem[]) {
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: DataTableItem[]) {
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 'id': return compare(+a.id, +b.id, isAsc);
case 'emailId': return compare(a.emailId, b.emailId , isAsc);
default: return 0;
}
});
}
}
/** Simple sort comparator for example ID/Name columns (for client-side sorting). */
function compare(a, b, isAsc) {
return (a < b ? -1 : 1) * (isAsc ? 1 : -1);
}
“请告诉我,如果您有任何解决方案”