在 Angular 2 中重新渲染数据表 - dtInstance.then 错误

Question

>我的 angular 2 应用程序中有一个组件，它有一个下拉列表和一个数据表。根据从下拉列表中选择的名称，我想在数据表中显示详细信息。

.HTML-

<div>
<select [(ngModel)]="selectedName">
<option *ngFor="let name of nameList" value= {{name.firstName}} >
{{name.firstName}}
</option>
</select>
<button id="submitName" (click)="getData()">Go</button>
</div>
<table #myTable [dtTrigger]="dtTrigger" datatable class="row-border hover">
<thead>
<tr>
<th>ID</th>
<th>First name</th>
<th>Last Name</th>
<th>Middle Name</th>
</tr>
</thead>
<tbody *ngIf="retrievedNames">

<tr *ngFor="let name of retrievedNames">
<td>{{name.id}}</td>
<td>{{name.firstName}}</td>
<td>{{name.lastName}}</td>
<td>{{name.middleName}}</td>
</tr>

</tbody>
</table>

我的组件.ts

import { Component, OnInit } from '@angular/core';
import { Http } from '@angular/http';
import { NetworkService } from './../services/network.service';
import { Subject } from 'rxjs/Rx';
import { Router } from '@angular/router';
import { DataTableDirective } from 'angular-datatables';
@Component({
selector: 'app-namedetails',
templateUrl: './namedetails.component.html',
styleUrls: ['./namedetails.component.css']
})
export class NameDetails implements OnInit {
@ViewChild("myTable") myTable:DataTableDirective;
private nameList: any;
private selectedName:string;
private retrievedNames: any;
dtTrigger: Subject<any> = new Subject();
dtElement: DataTableDirective;
dtOptions: DataTables.Settings = {};

constructor(private _http:Http, private networkservice : NetworkService,private router: Router) { 
}
ngOnInit() {
this.fetchFirstNames();
}
fetchFirstNames(){
this.networkservice.getAllFirstNames()
.subscribe(
res => {
console.log(res);
this.nameList = res;
});
}
fetchAllDetails(){
this.networkservice.getAllNames(this.selectedName)
.subscribe(
res => {
console.log(res);
this.retrievedNames = res;
this.myTable.dtInstance.then((dtInstance: DataTables.Api) => {
// Destroy the table first
dtInstance.destroy();
// Call the dtTrigger to rerender again
this.dtTrigger.next();
});
});
}

getData(){
this.fetchAllDetails();
}
}

但是，我不断收到以下错误 - "无法读取未定义的属性'然后'"。我该如何解决这个问题？

Answer 1

您需要将以下方法添加到component.ts类中：

ngAfterViewInit() {
this.dtTrigger.next();
}

否则永远不会触发实例的初始化，因此从一开始就不会创建 dtInstance;这就是它为 null 的原因。