Nativescript Switch 防止在初始绑定时触发更改事件 [英] Nativescript Switch prevent change event firing on initial binding

问题描述

我的模板如下

<ListView [items]="modules">
    <template let-item="item" >
        <StackLayout orientation="vertical">
                <Switch (checkedChange)="onSwitchModule(item.id,$event)" [checked]="item.active"></Switch>
        </StackLayout>
    </template>
</ListView>

我的控制器是

ngOnInit() {
    this._moduleService.getUserModules()
        .subscribe(
            response=>{
              this.modules = response.data;
            }
        )

}

onSwitchModule(itemId) {
   console.log(itemID); //Gets called on initial true binding on switch checked
}

每次页面加载时都会调用 onSwitchModule 并且 item.active 在任何项目上为 true，如何处理?

The onSwitchModule get called everytime the page loads with item.active is true on any item, how to handle this ?

注意:Nativescript 初学者

NOTE: Beginner in Nativescript

推荐答案

我为克服这个问题所做的是观察 tap 事件而不是 checkedChange:

What I did to overcome this is I watch for tap events instead of checkedChange:

<Switch (tap)="switchClicked" [checked]="item.active"></Switch>

并且在回调中，您可以从 bindingContext 获取当前项:

and in the callback, you can get the current item from bindingContext:

function switchClicked(args) {
  const item = args.object.bindingContext.item;
}

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