protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
// In Xamarin Forms > 3.0 this method is called when leaving the current view which in
// turn results in setting the adapter object even if the view has been destroyed.
// So explicitly return this method when Items are null;
if (sender.GetType() == typeof(MultiLevelListView))
{
var multiViewCtl = (MultiLevelListView)sender;
if (multiViewCtl.Items == null)
{
return;
}
}
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == MultiLevelListView.ItemsProperty.PropertyName)
{
_expandableListViewDataAdaptor = new ExpandableListViewDataAdaptor(this.Context as Activity, Element);
Control.SetAdapter(_expandableListViewDataAdaptor);
}
if (e.PropertyName == MultiLevelListView.ChildSelectedCommandProperty.PropertyName)
{
var selectedItem = Element.Items[((ExpandableListViewEventArgs)e).GroupPosition].ChildItems[((ExpandableListViewEventArgs)e).ChildPosition];
Element.ChildSelectedCommand?.Execute(selectedItem);
}
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
if (_expandableListViewDataAdaptor != null)
{
_expandableListViewDataAdaptor.Dispose();
_expandableListViewDataAdaptor = null;
}
}
protected override void OnElementChanged(ElementChangedEventArgs <MultiLevelListView> e)
{
base.OnElementChanged(e);
var control = new ExpandableListView(this.Context);
if (e.NewElement != null)
{
_expandableListViewDataAdaptor = new ExpandableListViewDataAdaptor(this.Context as Activity, e.NewElement);
control.SetAdapter(_expandableListViewDataAdaptor);
control.SetGroupIndicator(null);
control.SetOnGroupExpandListener(this);
control.SetOnGroupCollapseListener(this);
control.SetOnChildClickListener(this);
}
SetNativeControl(control);
}
