CommunityToolkit · michael-hawker · Apr 10, 2020 · Mar 31, 2020 · Mar 31, 2020 · Apr 1, 2020
diff --git a/Directory.Build.props b/Directory.Build.props
@@ -40,6 +40,16 @@
     </When>
   </Choose>
 
+  <Choose>
+    <When Condition="'$(Configuration)' == 'Debug' and '$(IsDesignProject)' != 'true'">
+      <!-- Debug builds have this turned on by default, but it breaks our Xaml Islands Scenarios -->
+      <PropertyGroup>
+        <EnableTypeInfoReflection>false</EnableTypeInfoReflection>
+        <EnableXBindDiagnostics>false</EnableXBindDiagnostics>
+      </PropertyGroup>
+    </When>
+  </Choose>
+
   <Choose>
     <When Condition="'$(IsTestProject)' != 'true' and '$(SourceLinkEnabled)' != 'false' and '$(IsSampleProject)' != 'true' and '$(IsDesignProject)' != 'true'">
       <PropertyGroup>

diff --git a/GazeInputTest/GazeInputTest.csproj b/GazeInputTest/GazeInputTest.csproj
@@ -150,7 +150,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
-      <Version>6.2.9</Version>
+      <Version>6.2.10</Version>
     </PackageReference>
     <PackageReference Include="StyleCop.Analyzers">
       <Version>1.0.2</Version>

diff --git a/Microsoft.Toolkit.Uwp.Connectivity/BluetoothLEHelper/BluetoothLEHelper.cs b/Microsoft.Toolkit.Uwp.Connectivity/BluetoothLEHelper/BluetoothLEHelper.cs
@@ -8,12 +8,12 @@
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using Windows.ApplicationModel.Core;
+using Microsoft.Toolkit.Uwp.Helpers;
 using Windows.Devices.Bluetooth;
 using Windows.Devices.Bluetooth.Advertisement;
 using Windows.Devices.Enumeration;
 using Windows.Foundation.Metadata;
-using Windows.UI.Core;
+using Windows.System;
 
 namespace Microsoft.Toolkit.Uwp.Connectivity
 {
@@ -59,11 +59,19 @@ public class BluetoothLEHelper
         /// </summary>
         private BluetoothAdapter _adapter;
 
+        /// <summary>
+        /// Gets or sets which DispatcherQueue is used to dispatch UI updates.
+        /// </summary>
+        public DispatcherQueue DispatcherQueue { get; set; }
+
         /// <summary>
         /// Prevents a default instance of the <see cref="BluetoothLEHelper" /> class from being created.
         /// </summary>
-        private BluetoothLEHelper()
+        /// <param name="dispatcherQueue">The DispatcherQueue that should be used to dispatch UI updates, or null if this is being called from the UI thread.</param>
+        private BluetoothLEHelper(DispatcherQueue dispatcherQueue = null)
         {
+            DispatcherQueue = dispatcherQueue ?? DispatcherQueue.GetForCurrentThread();
+
 #pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
             Init();
 #pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
@@ -201,8 +209,7 @@ private async Task Init()
         /// <param name="args">The advertisement.</param>
         private async void AdvertisementWatcher_Received(BluetoothLEAdvertisementWatcher sender, BluetoothLEAdvertisementReceivedEventArgs args)
         {
-            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                CoreDispatcherPriority.Normal,
+            await DispatcherQueue.ExecuteOnUIThreadAsync(
                 () =>
                 {
                     if (_readerWriterLockSlim.TryEnterReadLock(TimeSpan.FromSeconds(1)))
@@ -217,7 +224,7 @@ await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
 
                         _readerWriterLockSlim.ExitReadLock();
                     }
-                });
+                }, DispatcherQueuePriority.Normal);
         }
 
         /// <summary>
@@ -286,19 +293,20 @@ private async void DeviceWatcher_Removed(DeviceWatcher sender, DeviceInformation
             // Protect against race condition if the task runs after the app stopped the deviceWatcher.
             if (sender == _deviceWatcher)
             {
-                await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
-                {
-                    if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
+                await DispatcherQueue.ExecuteOnUIThreadAsync(
+                    () =>
                     {
-                        var device = BluetoothLeDevices.FirstOrDefault(i => i.DeviceInfo.Id == deviceInfoUpdate.Id);
-                        BluetoothLeDevices.Remove(device);
+                        if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
+                        {
+                            var device = BluetoothLeDevices.FirstOrDefault(i => i.DeviceInfo.Id == deviceInfoUpdate.Id);
+                            BluetoothLeDevices.Remove(device);
 
-                        var unusedDevice = _unusedDevices.FirstOrDefault(i => i.Id == deviceInfoUpdate.Id);
-                        _unusedDevices?.Remove(unusedDevice);
+                            var unusedDevice = _unusedDevices.FirstOrDefault(i => i.Id == deviceInfoUpdate.Id);
+                            _unusedDevices?.Remove(unusedDevice);
 
-                        _readerWriterLockSlim.ExitWriteLock();
-                    }
-                });
+                            _readerWriterLockSlim.ExitWriteLock();
+                        }
+                    }, DispatcherQueuePriority.Normal);
             }
         }
 
@@ -327,16 +335,15 @@ private async Task AddDeviceToList(DeviceInformation deviceInfo)
             // Make sure device name isn't blank or already present in the list.
             if (!string.IsNullOrEmpty(deviceInfo?.Name))
             {
-                var device = new ObservableBluetoothLEDevice(deviceInfo);
+                var device = new ObservableBluetoothLEDevice(deviceInfo, DispatcherQueue);
                 var connectable = (device.DeviceInfo.Properties.Keys.Contains("System.Devices.Aep.Bluetooth.Le.IsConnectable") &&
                                         (bool)device.DeviceInfo.Properties["System.Devices.Aep.Bluetooth.Le.IsConnectable"]) ||
                                         (device.DeviceInfo.Properties.Keys.Contains("System.Devices.Aep.IsConnected") &&
                                         (bool)device.DeviceInfo.Properties["System.Devices.Aep.IsConnected"]);
 
                 if (connectable)
                 {
-                    await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                        CoreDispatcherPriority.Normal,
+                    await DispatcherQueue.ExecuteOnUIThreadAsync(
                         () =>
                         {
                             if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
@@ -348,7 +355,7 @@ await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
 
                                 _readerWriterLockSlim.ExitWriteLock();
                             }
-                        });
+                        }, DispatcherQueuePriority.Normal);
 
                     return;
                 }

diff --git a/Microsoft.Toolkit.Uwp.Connectivity/BluetoothLEHelper/ObservableBluetoothLEDevice.cs b/Microsoft.Toolkit.Uwp.Connectivity/BluetoothLEHelper/ObservableBluetoothLEDevice.cs
@@ -11,10 +11,11 @@
 using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
-using Windows.ApplicationModel.Core;
+using Microsoft.Toolkit.Uwp.Helpers;
 using Windows.Devices.Bluetooth;
 using Windows.Devices.Bluetooth.GenericAttributeProfile;
 using Windows.Devices.Enumeration;
+using Windows.System;
 using Windows.UI.Core;
 using Windows.UI.Xaml.Media.Imaging;
 
@@ -134,17 +135,25 @@ public int Compare(object x, object y)
         private ObservableCollection<ObservableGattDeviceService> _services =
             new ObservableCollection<ObservableGattDeviceService>();
 
+        /// <summary>
+        /// Gets or sets which DispatcherQueue is used to dispatch UI updates.
+        /// </summary>
+        public DispatcherQueue DispatcherQueue { get; set; }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="ObservableBluetoothLEDevice"/> class.
         /// </summary>
         /// <param name="deviceInfo">The device information.</param>
-        public ObservableBluetoothLEDevice(DeviceInformation deviceInfo)
+        /// <param name="dispatcherQueue">The DispatcherQueue that should be used to dispatch UI updates for this BluetoothLE Device, or null if this is being called from the UI thread.</param>
+        public ObservableBluetoothLEDevice(DeviceInformation deviceInfo, DispatcherQueue dispatcherQueue = null)
         {
             DeviceInfo = deviceInfo;
             Name = DeviceInfo.Name;
 
             IsPaired = DeviceInfo.Pairing.IsPaired;
 
+            DispatcherQueue = dispatcherQueue ?? DispatcherQueue.GetForCurrentThread();
+
             LoadGlyph();
 
             this.PropertyChanged += ObservableBluetoothLEDevice_PropertyChanged;
@@ -395,7 +404,8 @@ private void ObservableBluetoothLEDevice_PropertyChanged(object sender, Property
         /// <exception cref="Exception">Thorws Exception when no permission to access device</exception>
         public async Task ConnectAsync()
         {
-            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, async () =>
+            await DispatcherQueue.ExecuteOnUIThreadAsync(
+                async () =>
             {
                 if (BluetoothLEDevice == null)
                 {
@@ -442,7 +452,7 @@ await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPrio
                         throw new Exception(_result.ProtocolError.GetErrorString());
                     }
                 }
-            });
+            }, DispatcherQueuePriority.Normal);
         }
 
         /// <summary>
@@ -468,8 +478,7 @@ public async Task DoInAppPairingAsync()
         /// <returns>The task of the update.</returns>
         public async Task UpdateAsync(DeviceInformationUpdate deviceUpdate)
         {
-            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                CoreDispatcherPriority.Normal,
+            await DispatcherQueue.ExecuteOnUIThreadAsync(
                 () =>
                 {
                     DeviceInfo.Update(deviceUpdate);
@@ -479,7 +488,7 @@ await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
 
                     LoadGlyph();
                     OnPropertyChanged("DeviceInfo");
-                });
+                }, DispatcherQueuePriority.Normal);
         }
 
         /// <summary>
@@ -512,9 +521,7 @@ protected virtual void OnPropertyChanged([CallerMemberName] string propertyName
         /// <param name="args">The arguments.</param>
         private async void BluetoothLEDevice_NameChanged(BluetoothLEDevice sender, object args)
         {
-            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                CoreDispatcherPriority.Normal,
-                () => { Name = BluetoothLEDevice.Name; });
+            await DispatcherQueue.ExecuteOnUIThreadAsync(() => { Name = BluetoothLEDevice.Name; }, DispatcherQueuePriority.Normal);
         }
 
         /// <summary>
@@ -524,29 +531,27 @@ await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
         /// <param name="args">The arguments.</param>
         private async void BluetoothLEDevice_ConnectionStatusChanged(BluetoothLEDevice sender, object args)
         {
-            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                CoreDispatcherPriority.Normal,
+            await DispatcherQueue.ExecuteOnUIThreadAsync(
                 () =>
                 {
                     IsPaired = DeviceInfo.Pairing.IsPaired;
                     IsConnected = BluetoothLEDevice.ConnectionStatus == BluetoothConnectionStatus.Connected;
-                });
+                }, DispatcherQueuePriority.Normal);
         }
 
         /// <summary>
         /// Load the glyph for this device
         /// </summary>
         private async void LoadGlyph()
         {
-            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                CoreDispatcherPriority.Normal,
+            await DispatcherQueue.ExecuteOnUIThreadAsync(
                 async () =>
                 {
                     var deviceThumbnail = await DeviceInfo.GetGlyphThumbnailAsync();
                     var glyphBitmapImage = new BitmapImage();
                     await glyphBitmapImage.SetSourceAsync(deviceThumbnail);
                     Glyph = glyphBitmapImage;
-                });
+                }, DispatcherQueuePriority.Normal);
         }
     }
 }
diff --git a/Microsoft.Toolkit.Uwp.Connectivity/BluetoothLEHelper/ObservableGattCharacteristics.cs b/Microsoft.Toolkit.Uwp.Connectivity/BluetoothLEHelper/ObservableGattCharacteristics.cs
@@ -7,10 +7,12 @@
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
+using Microsoft.Toolkit.Uwp.Helpers;
 using Windows.Devices.Bluetooth;
 using Windows.Devices.Bluetooth.GenericAttributeProfile;
 using Windows.Security.Cryptography;
 using Windows.Storage.Streams;
+using Windows.System;
 
 namespace Microsoft.Toolkit.Uwp.Connectivity
 {
@@ -110,13 +112,21 @@ public enum DisplayTypes
         /// </summary>
         private string _value;
 
+        /// <summary>
+        /// Gets or sets which DispatcherQueue is used to dispatch UI updates.
+        /// </summary>
+        public DispatcherQueue DispatcherQueue { get; set; }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="ObservableGattCharacteristics"/> class.
         /// </summary>
         /// <param name="characteristic">The characteristic.</param>
         /// <param name="parent">The parent.</param>
-        public ObservableGattCharacteristics(GattCharacteristic characteristic, ObservableGattDeviceService parent)
+        /// <param name="dispatcherQueue">The DispatcherQueue that should be used to dispatch UI updates, or null if this is being called from the UI thread.</param>
+        public ObservableGattCharacteristics(GattCharacteristic characteristic, ObservableGattDeviceService parent, DispatcherQueue dispatcherQueue = null)
         {
+            DispatcherQueue = dispatcherQueue ?? DispatcherQueue.GetForCurrentThread();
+
             Characteristic = characteristic;
             Parent = parent;
             Name = GattUuidsService.ConvertUuidToName(Characteristic.Uuid);
@@ -459,9 +469,7 @@ protected virtual void OnPropertyChanged([CallerMemberName] string propertyName
         /// <param name="args">The <see cref="GattValueChangedEventArgs"/> instance containing the event data.</param>
         private async void Characteristic_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
         {
-            await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
-                Windows.UI.Core.CoreDispatcherPriority.Normal,
-                () => { SetValue(args.CharacteristicValue); });
+            await DispatcherQueue.ExecuteOnUIThreadAsync(() => { SetValue(args.CharacteristicValue); }, DispatcherQueuePriority.Normal);
         }
 
         /// <summary>

diff --git a/Microsoft.Toolkit.Uwp.SampleApp/Controls/CodeRenderer.cs b/Microsoft.Toolkit.Uwp.SampleApp/Controls/CodeRenderer.cs
@@ -87,10 +87,14 @@ protected override void OnApplyTemplate()
 
         private void RenderDocument()
         {
-            _codeView?.Blocks?.Clear();
-            _formatter = new RichTextBlockFormatter(_theme);
-            _formatter.FormatRichTextBlock(_displayedText, _language, _codeView);
-            _rendered = true;
+            if (_codeView != null)
+            {
+                _codeView.Blocks?.Clear();
+                _formatter = new RichTextBlockFormatter(_theme);
+
+                _formatter.FormatRichTextBlock(_displayedText, _language, _codeView);
+                _rendered = true;
+            }
         }
 
         private void CopyButton_Click(object sender, RoutedEventArgs e)

diff --git a/Microsoft.Toolkit.Uwp.SampleApp/Microsoft.Toolkit.Uwp.SampleApp.csproj b/Microsoft.Toolkit.Uwp.SampleApp/Microsoft.Toolkit.Uwp.SampleApp.csproj
@@ -106,7 +106,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
-      <Version>6.2.9</Version>
+      <Version>6.2.10</Version>
     </PackageReference>
     <PackageReference Include="Microsoft.Services.Store.Engagement">
       <Version>10.1901.28001</Version>
@@ -292,7 +292,7 @@
     <Content Include="SamplePages\CameraHelper\CameraHelper.png" />
     <Content Include="SamplePages\Connected Animations\ConnectedAnimations.png" />
     <Content Include="SamplePages\DataGrid\DataGrid.png" />
-    <Content Include="SamplePages\DispatcherHelper\DispatchHelper.png" />
+    <Content Include="SamplePages\DispatcherQueueHelper\DispatchQueueHelper.png" />
     <Content Include="SamplePages\DockPanel\DockPanel.png" />
     <Content Include="SamplePages\Facebook Service\FacebookLogo.png" />
     <Content Include="SamplePages\LoginButton\LoginButton.png" />
@@ -456,7 +456,7 @@
     <Content Include="SamplePages\InAppNotification\InAppNotificationXaml.bind" />
     <Content Include="SamplePages\ListViewExtensions\ListViewExtensionsCode.bind" />
     <Content Include="SamplePages\Implicit Animations\ImplicitAnimationsCode.bind" />
-    <Content Include="SamplePages\DispatcherHelper\DispatcherHelperCode.bind" />
+    <Content Include="SamplePages\DispatcherQueueHelper\DispatcherQueueHelperCode.bind" />
     <Content Include="SamplePages\TextToolbar\TextToolbar.bind" />
     <Content Include="SamplePages\DockPanel\DockPanel.bind">
       <SubType>Designer</SubType>
@@ -726,8 +726,8 @@
     <Compile Include="SamplePages\BackgroundTaskHelper\BackgroundTaskHelperPage.xaml.cs">
       <DependentUpon>BackgroundTaskHelperPage.xaml</DependentUpon>
     </Compile>
-    <Compile Include="SamplePages\DispatcherHelper\DispatcherHelperPage.xaml.cs">
-      <DependentUpon>DispatcherHelperPage.xaml</DependentUpon>
+    <Compile Include="SamplePages\DispatcherQueueHelper\DispatcherQueueHelperPage.xaml.cs">
+      <DependentUpon>DispatcherQueueHelperPage.xaml</DependentUpon>
     </Compile>
     <Compile Include="SamplePages\DropShadowPanel\DropShadowPanelPage.xaml.cs">
       <DependentUpon>DropShadowPanelPage.xaml</DependentUpon>
@@ -1151,7 +1151,7 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
-    <Page Include="SamplePages\DispatcherHelper\DispatcherHelperPage.xaml">
+    <Page Include="SamplePages\DispatcherQueueHelper\DispatcherQueueHelperPage.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>

diff --git a/...Pages/DispatcherHelper/DispatchHelper.png → ...atcherQueueHelper/DispatchQueueHelper.png b/...Pages/DispatcherHelper/DispatchHelper.png → ...atcherQueueHelper/DispatchQueueHelper.png
diff --git a/...ispatcherHelper/DispatcherHelperCode.bind → ...ueueHelper/DispatcherQueueHelperCode.bind b/...ispatcherHelper/DispatcherHelperCode.bind → ...ueueHelper/DispatcherQueueHelperCode.bind
@@ -1,8 +1,12 @@
+// From a UI thread, capture the DispatcherQueue once:
+var dispatcherQueue = DispatcherQueue.GetForCurrentThread();
+
+// The use it from any other thread
 int crossThreadReturnedValue = await Task.Run<int>( async () =>
 	{
 		// Task.Run() will guarantee the given piece of code be executed on a seperate thread pool. 
 		// This is used to simulate the scenario of updating the UI element from a different thread.
-		int returnedFromUIThread = await DispatcherHelper.ExecuteOnUIThreadAsync<int>(() =>
+		int returnedFromUIThread = await dispatcherQueue.ExecuteOnUIThreadAsync<int>(() =>
 			{
 				NormalTextBlock.Text = "Updated from a random thread!";
 				return 1;

diff --git a/...ispatcherHelper/DispatcherHelperPage.xaml → ...ueueHelper/DispatcherQueueHelperPage.xaml b/...ispatcherHelper/DispatcherHelperPage.xaml → ...ueueHelper/DispatcherQueueHelperPage.xaml
@@ -1,4 +1,4 @@
-<Page x:Class="Microsoft.Toolkit.Uwp.SampleApp.SamplePages.DispatcherHelperPage"
+<Page x:Class="Microsoft.Toolkit.Uwp.SampleApp.SamplePages.DispatcherQueueHelperPage"
       xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
       xmlns:d="http://schemas.microsoft.com/expression/blend/2008"