使用 Xamarin 表单,如何更改默认选择器视图以显示在 PopoverController 中?下面的代码抛出“无法从没有窗口的视图中呈现弹出框”。在 iOS 上。
public class BindablePickerRenderer : PickerRenderer {
private UIPickerView picker;
protected override void OnElementChanged(ElementChangedEventArgs<Picker> e) {
base.OnElementChanged(e);
this.picker = new UIPickerView() {
Source = (UIPickerViewModel) new PickerSource(e.NewElement)
};
var popoverContent = new UIViewController();
popoverContent.View = picker;
var popoverController = new UIPopoverController(popoverContent);
popoverController.PopoverContentSize = new SizeF(320, 180);
popoverController.PresentFromRect(picker.Frame, this.Control.InputView, UIPopoverArrowDirection.Up, true);
}
}