protected override void OnApplyTemplate()
{
_templateSettings = new TreeViewItemTemplateSettings();
TreeViewItemExtension.SetTemplateSettings(AttachedFrameworkElement, _templateSettings);
_contentPresenterBorder = GetTemplateChild <Border>("ContentPresenterBorder");
SetLeftIndentLengthSettings();
}
public void SetLeftIndentLengthSettings()
{
var indentLength = TreeViewItemExtension.GetItemIndentLength(AttachedFrameworkElement);
var count = AttachedFrameworkElement.FindAscendantCount <TreeViewItem, TreeView>();
var leftIndentLengthDelta = count > 0 ? indentLength * count : 0;
_templateSettings.SetValue(TreeViewItemTemplateSettings.ItemIndentThicknessDeltaProperty, new Thickness(leftIndentLengthDelta, 0, 0, 0));
}