我有一个Angular 2组件,它加载并显示* ngFor中的用户的复选框列表,该列表也可以根据键过滤.我需要选择所有过滤的项目并将它们添加到数组中.我可以检查所有的复选框,但问题是当我更改检查有问题的更改事件不触发,任何想法如何解决这个问题?
模板:
<div class="form-group"> <input type="text" class="form-control" id="stringKeyFilter" placeholder="Key Filter" [(ngModel)]="keyFilter"> </div> <table class="table table-striped table-hover"> <thead> <tr> <th>Id</th> <th style="width: 150px;">Action</th> </tr> </thead> <tbody> <tr *ngFor="let device of devices| stringFilter: keyFilter"> <td> {{device.$key}} </td> <td> <div class="checkBox"> <label> <input type="checkBox" [checked]="selectAll || selectedDevices.indexOf(device.$key) > -1" (change)="updateSelectedDevices(device.$key,$event)" > View</label> </div> </td> </tr> </tbody> </table> <div class="btn-group pull-right"> <button type="button" class="btn btn-primary" (click)="selectAllDevices()">Select All</button> <button type="button" class="btn btn-default" (click)="deselectAllDevices()">Deselect All </button> </div>
零件:
@Component({ moduleId: module.id,selector: 'device-list',template: template }) export class DeviceListComponent implements OnInit { devicesObservable: FirebaseListObservable<Device[]>; devices: Device[] = []; isLoading: boolean = true; selectedDevices: string[] = []; selectAll: boolean = false; allCtrl: any; keyFilter: string = ''; constructor(private af: AngularFire) { } ngOnInit(): void { this.devicesObservable = this.af.database.list('/online',{ query: { orderByKey: true,} }); this.devicesObservable.subscribe((devicesData)=> { this.devices = devicesData; this.isLoading = false }); } updateSelectedDevices(deviceId: string,event): void { if (event.target.checked) { this.selectedDevices.push(deviceId); } else { _.pull(this.selectedDevices,deviceId); } } loadingDeviceDetail(loading: boolean): void { this.isLoading = loading; } selectAllDevices(): void { this.selectAll = true; } deselectAllDevices(): void { this.selectAll = false; this.selectedDevices = []; } }
更新
原文链接:https://www.f2er.com/angularjs/142949.html更新示例代码和空格以演示选择/取消选中所有过滤列表的复选框.
根据我的理解,过滤器行为从Angular1改变为Angular2.
在Angular1中,当数据或过滤器参数被修改时,DOM(网页)将被重新计算. (我也许错了,太久以前:P)
在Angular2中,简而言之,修改数据(数组)不会触发过滤器的计算,所以没有新的结果,不会更新到DOM.
长期和正式的解释在这里:Angular2 Pipes – ts.如果您坚持在模板中使用管道(过滤器),您应该探索文档中不纯的管道部分.
另一个解决方案是不要使用带* ngFor的过滤器.创建过滤的列表.
Plunker
http://plnkr.co/edit/pEpaj0?p=preview
示例代码
app.component.ts
import {Component} from '@angular/core'; import {bootstrap} from '@angular/platform-browser-dynamic'; @Component({ selector: 'material-app',templateUrl: 'app.component.html' }) export class AppComponent { title='How to select all filtered checkBoxes inside ngFor in Angular 2?'; url='https://stackoverflow.com/questions/39703103/'; device = [ {'name':'abc','checked':false},{'name':'abcd',{'name':'abcde',{'name':'abc123',{'name':'abc1234','checked':false}]; deviceFilter = ''; deviceFiltered = this.device.slice(0); selectFiltered(){ this.deviceFiltered.forEach(i=>i.checked=true); } deSelectFiltered(){ this.deviceFiltered.forEach(i=>i.checked=false); } onFilterChange(){ if (this.deviceFilter.length > 0) { this.deviceFiltered = this.device.filter(i => i.name.indexOf(this.deviceFilter) > -1); console.log(this.deviceFiltered); } else { this.deviceFiltered = this.device.slice(0); } } }
app.component.html
<h2><a [href]="titleUrl">{{title}}</a></h2> <div> Filter <input [(ngModel)]="deviceFilter" (ngModelChange)="onFilterChange()"> </div> <div> List: <ul> <li *ngFor="let i of device"> <input type="checkBox" [(ngModel)]="i.checked">{{i.name}} </li> </ul> </div> <div> Filtered List: <ul> <li *ngFor="let i of deviceFiltered"> <input type="checkBox" [(ngModel)]="i.checked">{{i.name}} </li> </ul> <button (click)="selectFiltered()">Select Filtered</button> <button (click)="deSelectFiltered()">Deselect Filtered</button> </div>