From d64ec6a7626f5cfb559e6e32aeb2ec49fb8c2185 Mon Sep 17 00:00:00 2001
From: danwalmsley <dan@walms.co.uk>
Date: Wed, 6 Nov 2019 21:10:19 +0000
Subject: [PATCH 1/2] set Scroll before calling base.OnTemplateApplied.

---
 src/Avalonia.Controls/ListBox.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/ListBox.cs b/src/Avalonia.Controls/ListBox.cs
index b15a6ce668..4966e669ed 100644
--- a/src/Avalonia.Controls/ListBox.cs
+++ b/src/Avalonia.Controls/ListBox.cs
@@ -151,8 +151,8 @@ namespace Avalonia.Controls
 
         protected override void OnTemplateApplied(TemplateAppliedEventArgs e)
         {
-            base.OnTemplateApplied(e);
             Scroll = e.NameScope.Find<IScrollable>("PART_ScrollViewer");
+            base.OnTemplateApplied(e);
         }
     }
 }

From ca60f9e70d457b5d910064aad6c3c6210f466455 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Wed, 6 Nov 2019 22:12:17 +0000
Subject: [PATCH 2/2] add unit test

---
 .../ListBoxTests.cs                           | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs b/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
index 9a459328aa..df2508a3ed 100644
--- a/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
@@ -47,6 +47,26 @@ namespace Avalonia.Controls.UnitTests
             Assert.IsType<ItemsPresenter>(target.Presenter);
         }
 
+        [Fact]
+        public void ListBox_Should_Find_Scrollviewer_In_Template()
+        {
+            var target = new ListBox
+            {
+                Template = ListBoxTemplate(),
+            };
+
+            ScrollViewer viewer = null;
+
+            target.TemplateApplied += (sender, e) =>
+            {
+                viewer = target.Scroll as ScrollViewer;
+            };
+
+            Prepare(target);
+
+            Assert.NotNull(viewer);
+        }
+
         [Fact]
         public void ListBoxItem_Containers_Should_Be_Generated()
         {