diff --git a/Avalonia.sln b/Avalonia.sln
index c06996ba0e..928ba71ec8 100644
--- a/Avalonia.sln
+++ b/Avalonia.sln
@@ -156,6 +156,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.DesignerSupport.Te
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.DesignerSupport.TestApp", "tests\Avalonia.DesignerSupport.TestApp\Avalonia.DesignerSupport.TestApp.csproj", "{F1381F98-4D24-409A-A6C5-1C5B1E08BB08}"
EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "VirtualizationTest", "samples\VirtualizationTest\VirtualizationTest.csproj", "{FBCAF3D0-2808-4934-8E96-3F607594517B}"
+EndProject
Global
GlobalSection(SharedMSBuildProjectFiles) = preSolution
src\Shared\RenderHelpers\RenderHelpers.projitems*{fb05ac90-89ba-4f2f-a924-f37875fb547c}*SharedItemsImports = 4
@@ -1899,6 +1901,38 @@ Global
{F1381F98-4D24-409A-A6C5-1C5B1E08BB08}.Release|iPhoneSimulator.Build.0 = Release|Any CPU
{F1381F98-4D24-409A-A6C5-1C5B1E08BB08}.Release|x86.ActiveCfg = Release|Any CPU
{F1381F98-4D24-409A-A6C5-1C5B1E08BB08}.Release|x86.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|Any CPU.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|Any CPU.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|iPhone.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|iPhone.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|iPhoneSimulator.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|iPhoneSimulator.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|x86.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Ad-Hoc|x86.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|Any CPU.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|Any CPU.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|iPhone.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|iPhone.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|iPhoneSimulator.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|iPhoneSimulator.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|x86.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.AppStore|x86.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|iPhone.ActiveCfg = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|iPhone.Build.0 = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|iPhoneSimulator.ActiveCfg = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|iPhoneSimulator.Build.0 = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|x86.ActiveCfg = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Debug|x86.Build.0 = Debug|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|Any CPU.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|iPhone.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|iPhone.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|iPhoneSimulator.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|iPhoneSimulator.Build.0 = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|x86.ActiveCfg = Release|Any CPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}.Release|x86.Build.0 = Release|Any CPU
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
@@ -1949,5 +1983,6 @@ Global
{D35A9F3D-8BB0-496E-BF72-444038A7DEBB} = {C5A00AC3-B34C-4564-9BDD-2DA473EF4D8B}
{52F55355-D120-42AC-8116-8410A7D602FA} = {C5A00AC3-B34C-4564-9BDD-2DA473EF4D8B}
{F1381F98-4D24-409A-A6C5-1C5B1E08BB08} = {C5A00AC3-B34C-4564-9BDD-2DA473EF4D8B}
+ {FBCAF3D0-2808-4934-8E96-3F607594517B} = {9B9E3891-2366-4253-A952-D08BCEB71098}
EndGlobalSection
EndGlobal
diff --git a/samples/VirtualizationTest/App.config b/samples/VirtualizationTest/App.config
new file mode 100644
index 0000000000..88fa4027bd
--- /dev/null
+++ b/samples/VirtualizationTest/App.config
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/samples/VirtualizationTest/App.xaml b/samples/VirtualizationTest/App.xaml
new file mode 100644
index 0000000000..d9630eef58
--- /dev/null
+++ b/samples/VirtualizationTest/App.xaml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/samples/VirtualizationTest/App.xaml.cs b/samples/VirtualizationTest/App.xaml.cs
new file mode 100644
index 0000000000..14ab5b3f84
--- /dev/null
+++ b/samples/VirtualizationTest/App.xaml.cs
@@ -0,0 +1,16 @@
+// 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.
+
+using Avalonia;
+using Avalonia.Markup.Xaml;
+
+namespace VirtualizationTest
+{
+ public class App : Application
+ {
+ public override void Initialize()
+ {
+ AvaloniaXamlLoader.Load(this);
+ }
+ }
+}
diff --git a/samples/VirtualizationTest/MainWindow.xaml b/samples/VirtualizationTest/MainWindow.xaml
new file mode 100644
index 0000000000..3fd25eb176
--- /dev/null
+++ b/samples/VirtualizationTest/MainWindow.xaml
@@ -0,0 +1,18 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/samples/VirtualizationTest/MainWindow.xaml.cs b/samples/VirtualizationTest/MainWindow.xaml.cs
new file mode 100644
index 0000000000..952383dffb
--- /dev/null
+++ b/samples/VirtualizationTest/MainWindow.xaml.cs
@@ -0,0 +1,25 @@
+// 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.
+
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+using VirtualizationTest.ViewModels;
+
+namespace VirtualizationTest
+{
+ public class MainWindow : Window
+ {
+ public MainWindow()
+ {
+ this.InitializeComponent();
+ this.AttachDevTools();
+ DataContext = new MainWindowViewModel();
+ }
+
+ private void InitializeComponent()
+ {
+ AvaloniaXamlLoader.Load(this);
+ }
+ }
+}
diff --git a/samples/VirtualizationTest/Program.cs b/samples/VirtualizationTest/Program.cs
new file mode 100644
index 0000000000..5bbf01f428
--- /dev/null
+++ b/samples/VirtualizationTest/Program.cs
@@ -0,0 +1,20 @@
+// 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.
+
+using System;
+using Avalonia;
+using Avalonia.Controls;
+
+namespace VirtualizationTest
+{
+ class Program
+ {
+ static void Main(string[] args)
+ {
+ AppBuilder.Configure()
+ .UseWin32()
+ .UseDirect2D1()
+ .Start();
+ }
+ }
+}
diff --git a/samples/VirtualizationTest/Properties/AssemblyInfo.cs b/samples/VirtualizationTest/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000000..e6af64555b
--- /dev/null
+++ b/samples/VirtualizationTest/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("VirtualizationTest")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("VirtualizationTest")]
+[assembly: AssemblyCopyright("Copyright © 2016")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components. If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("fbcaf3d0-2808-4934-8e96-3f607594517b")]
+
+// Version information for an assembly consists of the following four values:
+//
+// Major Version
+// Minor Version
+// Build Number
+// Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/samples/VirtualizationTest/ViewModels/ItemViewModel.cs b/samples/VirtualizationTest/ViewModels/ItemViewModel.cs
new file mode 100644
index 0000000000..f0cf69c23e
--- /dev/null
+++ b/samples/VirtualizationTest/ViewModels/ItemViewModel.cs
@@ -0,0 +1,19 @@
+// 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.
+
+using System;
+
+namespace VirtualizationTest.ViewModels
+{
+ internal class ItemViewModel
+ {
+ private int _index;
+
+ public ItemViewModel(int index)
+ {
+ _index = index;
+ }
+
+ public string Header => $"Item {_index}";
+ }
+}
diff --git a/samples/VirtualizationTest/ViewModels/MainWindowViewModel.cs b/samples/VirtualizationTest/ViewModels/MainWindowViewModel.cs
new file mode 100644
index 0000000000..916568f7eb
--- /dev/null
+++ b/samples/VirtualizationTest/ViewModels/MainWindowViewModel.cs
@@ -0,0 +1,36 @@
+// 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.
+
+using System;
+using System.Linq;
+using ReactiveUI;
+
+namespace VirtualizationTest.ViewModels
+{
+ internal class MainWindowViewModel : ReactiveObject
+ {
+ private int _itemCount = 200;
+
+ public MainWindowViewModel()
+ {
+ this.WhenAnyValue(x => x.ItemCount).Subscribe(ResizeItems);
+ }
+
+ public int ItemCount
+ {
+ get { return _itemCount; }
+ set { this.RaiseAndSetIfChanged(ref _itemCount, value); }
+ }
+
+ public IReactiveList Items { get; private set; }
+
+ private void ResizeItems(int count)
+ {
+ if (Items == null)
+ {
+ var items = Enumerable.Range(0, count).Select(x => new ItemViewModel(x));
+ Items = new ReactiveList(items);
+ }
+ }
+ }
+}
diff --git a/samples/VirtualizationTest/VirtualizationTest.csproj b/samples/VirtualizationTest/VirtualizationTest.csproj
new file mode 100644
index 0000000000..bbe5882de9
--- /dev/null
+++ b/samples/VirtualizationTest/VirtualizationTest.csproj
@@ -0,0 +1,168 @@
+
+
+
+
+ Debug
+ AnyCPU
+ {FBCAF3D0-2808-4934-8E96-3F607594517B}
+ WinExe
+ Properties
+ VirtualizationTest
+ VirtualizationTest
+ v4.5.2
+ 512
+ true
+
+
+ AnyCPU
+ true
+ full
+ false
+ bin\Debug\
+ DEBUG;TRACE
+ prompt
+ 4
+
+
+ AnyCPU
+ pdbonly
+ true
+ bin\Release\
+ TRACE
+ prompt
+ 4
+
+
+
+
+
+
+ ..\..\packages\Splat.1.6.2\lib\Net45\Splat.dll
+ True
+
+
+
+
+ ..\..\packages\Rx-Core.2.2.5\lib\net45\System.Reactive.Core.dll
+ True
+
+
+ ..\..\packages\Rx-Interfaces.2.2.5\lib\net45\System.Reactive.Interfaces.dll
+ True
+
+
+ ..\..\packages\Rx-Linq.2.2.5\lib\net45\System.Reactive.Linq.dll
+ True
+
+
+ ..\..\packages\Rx-PlatformServices.2.2.5\lib\net45\System.Reactive.PlatformServices.dll
+ True
+
+
+
+
+
+
+
+
+
+
+ App.xaml
+
+
+ MainWindow.xaml
+
+
+
+
+
+
+
+
+
+
+
+
+ {d211e587-d8bc-45b9-95a4-f297c8fa5200}
+ Avalonia.Animation
+
+
+ {b09b78d8-9b26-48b0-9149-d64a2f120f3f}
+ Avalonia.Base
+
+
+ {d2221c82-4a25-4583-9b43-d791e3f6820c}
+ Avalonia.Controls
+
+
+ {799a7bb5-3c2c-48b6-85a7-406a12c420da}
+ Avalonia.DesignerSupport
+
+
+ {7062ae20-5dcc-4442-9645-8195bdece63e}
+ Avalonia.Diagnostics
+
+
+ {62024b2d-53eb-4638-b26b-85eeaa54866e}
+ Avalonia.Input
+
+
+ {6b0ed19d-a08b-461c-a9d9-a9ee40b0c06b}
+ Avalonia.Interactivity
+
+
+ {42472427-4774-4c81-8aff-9f27b8e31721}
+ Avalonia.Layout
+
+
+ {6417b24e-49c2-4985-8db2-3ab9d898ec91}
+ Avalonia.ReactiveUI
+
+
+ {eb582467-6abb-43a1-b052-e981ba910e3a}
+ Avalonia.SceneGraph
+
+
+ {f1baa01a-f176-4c6a-b39d-5b40bb1b148f}
+ Avalonia.Styling
+
+
+ {3e10a5fa-e8da-48b1-ad44-6a5b6cb7750f}
+ Avalonia.Themes.Default
+
+
+ {3e53a01a-b331-47f3-b828-4a5717e77a24}
+ Avalonia.Markup.Xaml
+
+
+ {6417e941-21bc-467b-a771-0de389353ce6}
+ Avalonia.Markup
+
+
+ {3e908f67-5543-4879-a1dc-08eace79b3cd}
+ Avalonia.Direct2D1
+
+
+ {811a76cf-1cf6-440f-963b-bbe31bd72a82}
+ Avalonia.Win32
+
+
+
+
+ Designer
+
+
+
+
+ Designer
+
+
+
+
+
\ No newline at end of file
diff --git a/samples/VirtualizationTest/VirtualizationTest.v2.ncrunchproject b/samples/VirtualizationTest/VirtualizationTest.v2.ncrunchproject
new file mode 100644
index 0000000000..f744eecae0
--- /dev/null
+++ b/samples/VirtualizationTest/VirtualizationTest.v2.ncrunchproject
@@ -0,0 +1,26 @@
+
+ true
+ 1000
+ false
+ false
+ false
+ true
+ false
+ false
+ true
+ false
+ false
+ true
+ true
+ false
+ true
+ true
+ true
+ 60000
+
+
+
+ AutoDetect
+ STA
+ x86
+
\ No newline at end of file
diff --git a/samples/VirtualizationTest/packages.config b/samples/VirtualizationTest/packages.config
new file mode 100644
index 0000000000..9613b3fccb
--- /dev/null
+++ b/samples/VirtualizationTest/packages.config
@@ -0,0 +1,9 @@
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs b/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs
index a5e04ad6d5..d938153d3c 100644
--- a/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs
+++ b/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs
@@ -97,7 +97,7 @@ namespace Avalonia.Controls.Presenters
var generator = Owner.ItemContainerGenerator;
var panel = VirtualizingPanel;
- if (!panel.IsFull)
+ if (!panel.IsFull && Items != null)
{
var index = LastIndex + 1;
var items = Items.Cast