Interactivity

This section explains about how to interact with TreeView and its items.

Interacting with TreeView items

Loaded event

The Loaded event is raised when the TreeView is loading in view for the first time.

treeView.Loaded += TreeView_Loaded;

private void TreeView_Loaded(object sender, TreeViewLoadedEventArgs e)
{
    Android.App.AlertDialog.Builder dialog = new Android.App.AlertDialog.Builder(this);
    Android.App.AlertDialog alert = dialog.Create();
    alert.SetMessage("Loaded");
    alert.Show();
}

The Loaded event is used for the following use case:

Tapped event

The ItemTapped event will be triggered whenever tapping the item. ItemTappedEventArgs has the following members which provides the information for ItemTapped event:

  • Node: Gets the TreeViewNode and data associated with the tapped item as its arguments.
  • Position: Gets the touch position in the tapped item.
  • Handled: Gets or sets whether the event is handled or not.
treeView.ItemTapped += TreeView_ItemTapped;

private void TreeView_ItemTapped(object sender, ItemTappedEventArgs e)
{
    Android.App.AlertDialog.Builder dialog = new Android.App.AlertDialog.Builder(this);
    Android.App.AlertDialog alert = dialog.Create();
    alert.SetMessage("ItemTapped");
    alert.Show();
}

ItemDoubleTapped event

The ItemDoubleTapped event will be triggered whenever double tapping the item. The ItemDoubleTappedEventArgs has the following members providing information for the ItemDoubleTapped event:

  • Node: Gets the TreeViewNode and data associated with the double tapped item as its arguments.
  • Position: Gets the touch position in the double tapped item.
  • Handled: Gets or sets whether the event is handled or not.
treeView.ItemDoubleTapped += TreeView_ItemDoubleTapped;

private void TreeView_ItemDoubleTapped(object sender, ItemDoubleTappedEventArgs e)
{
    Android.App.AlertDialog.Builder dialog = new Android.App.AlertDialog.Builder(this);
    Android.App.AlertDialog alert = dialog.Create();
    alert.SetMessage("ItemDoubleTapped");
    alert.Show();
}

ItemHolding event

The ItemHolding event will be triggered whenever the item is long pressed.
ItemHoldingEventArgs has the following members which provides the information for ItemHolding event:

  • Node: Gets the TreeViewNode and data associated with the hold item as its arguments.
  • Position: Gets the touch position in the hold item.
  • Handled: Gets or sets whether the event is handled or not.
treeView.ItemHolding += TreeView_ItemHolding;
private void TreeView_ItemHolding(object sender, ItemHoldingEventArgs e)
{
    Android.App.AlertDialog.Builder dialog = new Android.App.AlertDialog.Builder(this);
    Android.App.AlertDialog alert = dialog.Create();
    alert.SetMessage("ItemHolding");
    alert.Show();
}