private async void TreeView_LoadOnDemandEvent(object sender, LoadOnDemandEventArgs e)
{
if (e.Action == Action.RequestStatus)
{
e.HasChildNodes = (e.Node.Content as MusicInfo).HasChild;
}
else if (e.Action == Action.PopulateNodes)
{
var viewModel = new MusicInfoRepository();
var node = e.Node;
if (node.ChildNodes.Count > 0)
{
node.IsExpanded = true;
return;
}
node.ShowExpanderAnimation = true;
await Task.Delay(2000);
MusicInfo musicInfo = node.Content as MusicInfo;
var items = viewModel.GetSubMenu(musicInfo.ID);
node.PopulateChildNodes(items);
if (items.Count() > 0)
{
node.IsExpanded = true;
}
node.ShowExpanderAnimation = false;
}
}
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
SfTreeView treeView = FindViewById <SfTreeView>(Resource.Id.sfTreeView1);
MusicInfoRepository viewModel = new MusicInfoRepository();
treeView.LoadOnDemand += TreeView_LoadOnDemandEvent;
treeView.ItemsSource = viewModel.Menu;
treeView.Adapter = new NodeImageAdapter();
}