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
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>
