From 75fdd0d3432a033c0b8c93e8d583754c58a6a2e3 Mon Sep 17 00:00:00 2001 From: Steven Kirk Date: Mon, 7 Oct 2019 10:41:44 +0200 Subject: [PATCH] Check for empty items in GetContainerInDirection. Don't try to navigate into `TreeViewItem`s with no children: this causes a out-of-range exception. Fixes #2980 --- src/Avalonia.Controls/TreeView.cs | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/Avalonia.Controls/TreeView.cs b/src/Avalonia.Controls/TreeView.cs index cc47365214..8907137ecb 100644 --- a/src/Avalonia.Controls/TreeView.cs +++ b/src/Avalonia.Controls/TreeView.cs @@ -1,3 +1,4 @@ + // Copyright (c) The Avalonia Project. All rights reserved. // Licensed under the MIT license. See licence.md file in the project root for full license information. @@ -470,7 +471,7 @@ namespace Avalonia.Controls if (index > 0) { var previous = (TreeViewItem)parentGenerator.ContainerFromIndex(index - 1); - result = previous.IsExpanded ? + result = previous.IsExpanded && previous.ItemCount > 0 ? (TreeViewItem)previous.ItemContainerGenerator.ContainerFromIndex(previous.ItemCount - 1) : previous; } @@ -482,7 +483,7 @@ namespace Avalonia.Controls break; case NavigationDirection.Down: - if (from.IsExpanded && intoChildren) + if (from.IsExpanded && intoChildren && from.ItemCount > 0) { result = (TreeViewItem)from.ItemContainerGenerator.ContainerFromIndex(0); }