Prevent Automatic Horizontal Scroll in TreeView

Question

Whenever a node is selected in my treeview, it automatically does a horizontal scroll to that item. Is there a way to disable this?

Answer 1

@lena's solution of preserving vertical scrolling worked best for me. I've iterated on it a little bit:

    private void TreeViewItem_RequestBringIntoView(object sender, RequestBringIntoViewEventArgs e)
    {
        var treeViewItem = (TreeViewItem)sender;
        var scrollViewer = treeView.Template.FindName("_tv_scrollviewer_", treeView) as ScrollViewer;

        Point topLeftInTreeViewCoordinates = treeViewItem.TransformToAncestor(treeView).Transform(new Point(0, 0));
        var treeViewItemTop = topLeftInTreeViewCoordinates.Y;
        if (treeViewItemTop < 0
            || treeViewItemTop + treeViewItem.ActualHeight > scrollViewer.ViewportHeight
            || treeViewItem.ActualHeight > scrollViewer.ViewportHeight)
        {
            // if the item is not visible or too "tall", don't do anything; let them scroll it into view
            return;
        }

        // if the item is already fully within the viewport vertically, disallow horizontal scrolling
        e.Handled = true;
    }

What this does is let the ScrollViewer scroll normally if the item isn't already in the viewport vertically. However for the actual "annoying" case (where the item is already visible), it sets e.Handled to true, thus preventing horizontal scrolling.