diff --git a/.editorconfig b/.editorconfig
index 179491eece..337760636b 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -137,6 +137,11 @@ space_within_single_line_array_initializer_braces = true
 #Net Analyzer
 dotnet_analyzer_diagnostic.category-Performance.severity = none #error - Uncomment when all violations are fixed.
 
+# CA1802: Use literals where appropriate
+dotnet_diagnostic.CA1802.severity = warning
+# CA1825: Avoid zero-length array allocations
+dotnet_diagnostic.CA1825.severity = warning
+
 # Wrapping preferences
 csharp_wrap_before_ternary_opsigns = false
 
diff --git a/NOTICE.md b/NOTICE.md
index 92fd725957..e97fc654c9 100644
--- a/NOTICE.md
+++ b/NOTICE.md
@@ -111,7 +111,7 @@ DEALINGS IN THE SOFTWARE.
 
 # Metsys.Bson
 
-Copyright (c) 2010, Karl Seguin - http://www.openmymind.net/
+Copyright (c) 2010, Karl Seguin - https://www.openmymind.net/
 All rights reserved.
  
 Redistribution and use in source and binary forms, with or without
@@ -302,4 +302,4 @@ https://github.com/chromium/chromium
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/src/Android/Avalonia.Android/AvaloniaView.cs b/src/Android/Avalonia.Android/AvaloniaView.cs
index 34fa121cd7..94e863210b 100644
--- a/src/Android/Avalonia.Android/AvaloniaView.cs
+++ b/src/Android/Avalonia.Android/AvaloniaView.cs
@@ -74,7 +74,7 @@ namespace Avalonia.Android
 
         class ViewImpl : TopLevelImpl
         {
-            public ViewImpl(AvaloniaView avaloniaView) : base(avaloniaView, true)
+            public ViewImpl(AvaloniaView avaloniaView) : base(avaloniaView)
             {
                 View.Focusable = true;
                 View.FocusChange += ViewImpl_FocusChange;
diff --git a/src/Avalonia.Base/Media/TextFormatting/Unicode/GraphemeBreak.cs b/src/Avalonia.Base/Media/TextFormatting/Unicode/GraphemeBreak.cs
index 6986b908a1..d0ceba62f4 100644
--- a/src/Avalonia.Base/Media/TextFormatting/Unicode/GraphemeBreak.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/Unicode/GraphemeBreak.cs
@@ -2,6 +2,6 @@ namespace Avalonia.Media.TextFormatting.Unicode
 {
     internal static class GraphemeBreak
     {
-        public static byte[] Data => new byte[0];
+        public static byte[] Data => System.Array.Empty<byte>();
     }
 }
diff --git a/src/Avalonia.Controls/TextBox.cs b/src/Avalonia.Controls/TextBox.cs
index 964a153c8b..da4e90fb66 100644
--- a/src/Avalonia.Controls/TextBox.cs
+++ b/src/Avalonia.Controls/TextBox.cs
@@ -18,6 +18,7 @@ using Avalonia.Media.TextFormatting;
 using Avalonia.Media.TextFormatting.Unicode;
 using Avalonia.Automation.Peers;
 using System.Diagnostics;
+using Avalonia.Threading;
 
 namespace Avalonia.Controls
 {
@@ -159,18 +160,41 @@ namespace Avalonia.Controls
                 (o, v) => o.UndoLimit = v,
                 unsetValue: -1);
 
+        /// <summary>
+        /// Defines the <see cref="CopyingToClipboard"/> event.
+        /// </summary>
         public static readonly RoutedEvent<RoutedEventArgs> CopyingToClipboardEvent =
             RoutedEvent.Register<TextBox, RoutedEventArgs>(
                 nameof(CopyingToClipboard), RoutingStrategies.Bubble);
 
+        /// <summary>
+        /// Defines the <see cref="CuttingToClipboard"/> event.
+        /// </summary>
         public static readonly RoutedEvent<RoutedEventArgs> CuttingToClipboardEvent =
             RoutedEvent.Register<TextBox, RoutedEventArgs>(
                 nameof(CuttingToClipboard), RoutingStrategies.Bubble);
 
+        /// <summary>
+        /// Defines the <see cref="PastingFromClipboard"/> event.
+        /// </summary>
         public static readonly RoutedEvent<RoutedEventArgs> PastingFromClipboardEvent =
             RoutedEvent.Register<TextBox, RoutedEventArgs>(
                 nameof(PastingFromClipboard), RoutingStrategies.Bubble);
 
+        /// <summary>
+        /// Defines the <see cref="TextChanged"/> event.
+        /// </summary>
+        public static readonly RoutedEvent<TextChangedEventArgs> TextChangedEvent =
+            RoutedEvent.Register<TextBox, TextChangedEventArgs>(
+                nameof(TextChanged), RoutingStrategies.Bubble);
+
+        /// <summary>
+        /// Defines the <see cref="TextChanging"/> event.
+        /// </summary>
+        public static readonly RoutedEvent<TextChangingEventArgs> TextChangingEvent =
+            RoutedEvent.Register<TextBox, TextChangingEventArgs>(
+                nameof(TextChanging), RoutingStrategies.Bubble);
+
         readonly struct UndoRedoState : IEquatable<UndoRedoState>
         {
             public string? Text { get; }
@@ -359,8 +383,8 @@ namespace Avalonia.Controls
         /// </summary>
         public double LineHeight
         {
-            get { return GetValue(LineHeightProperty); }
-            set { SetValue(LineHeightProperty, value); }
+            get => GetValue(LineHeightProperty);
+            set => SetValue(LineHeightProperty, value);
         }
 
         [Content]
@@ -376,11 +400,19 @@ namespace Avalonia.Controls
                 CaretIndex = CoerceCaretIndex(caretIndex, value);
                 SelectionStart = CoerceCaretIndex(selectionStart, value);
                 SelectionEnd = CoerceCaretIndex(selectionEnd, value);
-                if (SetAndRaise(TextProperty, ref _text, value) && IsUndoEnabled && !_isUndoingRedoing)
+
+                var textChanged = SetAndRaise(TextProperty, ref _text, value);
+
+                if (textChanged && IsUndoEnabled && !_isUndoingRedoing)
                 {
                     _undoRedoHelper.Clear();
                     SnapshotUndoRedo(); // so we always have an initial state
                 }
+
+                if (textChanged)
+                {
+                    RaiseTextChangeEvents();
+                }
             }
         }
 
@@ -564,6 +596,27 @@ namespace Avalonia.Controls
             remove => RemoveHandler(PastingFromClipboardEvent, value);
         }
 
+        /// <summary>
+        /// Occurs asynchronously after text changes and the new text is rendered.
+        /// </summary>
+        public event EventHandler<TextChangedEventArgs>? TextChanged
+        {
+            add => AddHandler(TextChangedEvent, value);
+            remove => RemoveHandler(TextChangedEvent, value);
+        }
+
+        /// <summary>
+        /// Occurs synchronously when text starts to change but before it is rendered.
+        /// </summary>
+        /// <remarks>
+        /// This event occurs just after the <see cref="Text"/> property value has been updated.
+        /// </remarks>
+        public event EventHandler<TextChangingEventArgs>? TextChanging
+        {
+            add => AddHandler(TextChangingEvent, value);
+            remove => RemoveHandler(TextChangingEvent, value);
+        }
+
         protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
         {
             _presenter = e.NameScope.Get<TextPresenter>("PART_TextPresenter");
@@ -1252,7 +1305,7 @@ namespace Avalonia.Controls
 
                 if (text != null && _wordSelectionStart >= 0)
                 {
-                    var distance = caretIndex - _wordSelectionStart;                 
+                    var distance = caretIndex - _wordSelectionStart;
 
                     if (distance <= 0)
                     {
@@ -1539,11 +1592,39 @@ namespace Avalonia.Controls
             return text.Substring(start, end - start);
         }
 
+        /// <summary>
+        /// Raises both the <see cref="TextChanging"/> and <see cref="TextChanged"/> events.
+        /// </summary>
+        /// <remarks>
+        /// This must be called after the <see cref="Text"/> property is set.
+        /// </remarks>
+        private void RaiseTextChangeEvents()
+        {
+            // Note the following sequence of these events (following WinUI)
+            // 1. TextChanging occurs synchronously when text starts to change but before it is rendered.
+            //    This occurs after the Text property is set.
+            // 2. TextChanged occurs asynchronously after text changes and the new text is rendered.
+
+            var textChangingEventArgs = new TextChangingEventArgs(TextChangingEvent);
+            RaiseEvent(textChangingEventArgs);
+
+            Dispatcher.UIThread.Post(() =>
+            {
+                var textChangedEventArgs = new TextChangedEventArgs(TextChangedEvent);
+                RaiseEvent(textChangedEventArgs);
+            }, DispatcherPriority.Normal);
+        }
+
         private void SetTextInternal(string value, bool raiseTextChanged = true)
         {
             if (raiseTextChanged)
             {
-                SetAndRaise(TextProperty, ref _text, value);
+                bool textChanged = SetAndRaise(TextProperty, ref _text, value);
+
+                if (textChanged)
+                {
+                    RaiseTextChangeEvents();
+                }
             }
             else
             {
diff --git a/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs b/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs
index d39d964277..5d5ffcc381 100644
--- a/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs
+++ b/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs
@@ -64,7 +64,7 @@ namespace Avalonia.Controls
 
                 return new TextInputMethodSurroundingText
                 {
-                    Text = lineText ?? "",                   
+                    Text = lineText ?? "",
                     AnchorOffset = anchorOffset,
                     CursorOffset = cursorOffset
                 };
diff --git a/src/Avalonia.Controls/TextChangedEventArgs.cs b/src/Avalonia.Controls/TextChangedEventArgs.cs
new file mode 100644
index 0000000000..77c609f19b
--- /dev/null
+++ b/src/Avalonia.Controls/TextChangedEventArgs.cs
@@ -0,0 +1,20 @@
+using Avalonia.Interactivity;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data specific to a TextChanged event.
+    /// </summary>
+    public class TextChangedEventArgs : RoutedEventArgs
+    {
+        public TextChangedEventArgs(RoutedEvent? routedEvent)
+            : base (routedEvent)
+        {
+        }
+
+        public TextChangedEventArgs(RoutedEvent? routedEvent, IInteractive? source)
+            : base(routedEvent, source)
+        {
+        }
+    }
+}
diff --git a/src/Avalonia.Controls/TextChangingEventArgs.cs b/src/Avalonia.Controls/TextChangingEventArgs.cs
new file mode 100644
index 0000000000..4dedbc927b
--- /dev/null
+++ b/src/Avalonia.Controls/TextChangingEventArgs.cs
@@ -0,0 +1,20 @@
+using Avalonia.Interactivity;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data specific to a TextChanging event.
+    /// </summary>
+    public class TextChangingEventArgs : RoutedEventArgs
+    {
+        public TextChangingEventArgs(RoutedEvent? routedEvent)
+            : base (routedEvent)
+        {
+        }
+
+        public TextChangingEventArgs(RoutedEvent? routedEvent, IInteractive? source)
+            : base(routedEvent, source)
+        {
+        }
+    }
+}
diff --git a/src/Avalonia.DesignerSupport/Remote/HtmlTransport/SimpleWebSocketHttpServer.cs b/src/Avalonia.DesignerSupport/Remote/HtmlTransport/SimpleWebSocketHttpServer.cs
index 6af21bbcf5..9a872df960 100644
--- a/src/Avalonia.DesignerSupport/Remote/HtmlTransport/SimpleWebSocketHttpServer.cs
+++ b/src/Avalonia.DesignerSupport/Remote/HtmlTransport/SimpleWebSocketHttpServer.cs
@@ -140,7 +140,7 @@ namespace Avalonia.DesignerSupport.Remote.HtmlTransport
                 IsWebsocketRequest = true;
                 if (headers.TryGetValue("Sec-WebSocket-Protocol", out h))
                     WebSocketProtocols = h.Split(',').Select(x => x.Trim()).ToArray();
-                else WebSocketProtocols = new string[0];
+                else WebSocketProtocols = Array.Empty<string>();
             }
         }
 
diff --git a/src/Avalonia.FreeDesktop/DBusMenuExporter.cs b/src/Avalonia.FreeDesktop/DBusMenuExporter.cs
index c0511420a6..657e324010 100644
--- a/src/Avalonia.FreeDesktop/DBusMenuExporter.cs
+++ b/src/Avalonia.FreeDesktop/DBusMenuExporter.cs
@@ -340,7 +340,7 @@ namespace Avalonia.FreeDesktop
             {
                 var id = item == null ? 0 : GetId(item);
                 var props = GetProperties((item, menu), propertyNames);
-                var children = (depth == 0 || menu == null) ? new object[0] : new object[menu.Items.Count];
+                var children = (depth == 0 || menu == null) ? Array.Empty<object>() : new object[menu.Items.Count];
                 if(menu != null)
                     for (var c = 0; c < children.Length; c++)
                     {
@@ -397,7 +397,7 @@ namespace Avalonia.FreeDesktop
             {
                 foreach (var e in Events)
                     HandleEvent(e.id, e.eventId, e.data, e.timestamp);
-                return Task.FromResult(new int[0]);
+                return Task.FromResult(Array.Empty<int>());
             }
 
             public async Task<bool> AboutToShowAsync(int Id)
@@ -407,7 +407,7 @@ namespace Avalonia.FreeDesktop
 
             public async Task<(int[] updatesNeeded, int[] idErrors)> AboutToShowGroupAsync(int[] Ids)
             {
-                return (new int[0], new int[0]);
+                return (Array.Empty<int>(), Array.Empty<int>());
             }
 
             #region Events
diff --git a/src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs b/src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs
index ce210019c0..5c7ec2bbd2 100644
--- a/src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs
+++ b/src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs
@@ -99,7 +99,7 @@ namespace Avalonia.LinuxFramebuffer.Output
             // prepare for the new ioctl call
             var handles = new uint[] {handle, 0, 0, 0};
             var pitches = new uint[] {stride, 0, 0, 0};
-            var offsets = new uint[] {};
+            var offsets = Array.Empty<uint>();
 
             var ret = drmModeAddFB2(_card.Fd, w, h, format, handles, pitches,
                                     offsets, out var fbHandle, 0);
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/Avalonia.Markup.Xaml.Loader.csproj b/src/Markup/Avalonia.Markup.Xaml.Loader/Avalonia.Markup.Xaml.Loader.csproj
index ce931b9c14..debdece60f 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/Avalonia.Markup.Xaml.Loader.csproj
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/Avalonia.Markup.Xaml.Loader.csproj
@@ -5,6 +5,11 @@
     <IsPackable>true</IsPackable>
     <PackageId>Avalonia.Markup.Xaml.Loader</PackageId>
     <DefineConstants>$(DefineConstants);XAMLX_INTERNAL</DefineConstants>
+    <LangVersion>10</LangVersion>
+  </PropertyGroup>
+  <!--Disable Net Perf. analyzer for submodule to avoid commit issue -->
+  <PropertyGroup>
+    <EnableNETAnalyzers>false</EnableNETAnalyzers>
   </PropertyGroup>
   <Import Project="IncludeXamlIlSre.props" />
   <ItemGroup>
diff --git a/src/Windows/Avalonia.Win32/Win32Platform.cs b/src/Windows/Avalonia.Win32/Win32Platform.cs
index 29b4baeeb0..3cdc3586dc 100644
--- a/src/Windows/Avalonia.Win32/Win32Platform.cs
+++ b/src/Windows/Avalonia.Win32/Win32Platform.cs
@@ -241,8 +241,8 @@ namespace Avalonia.Win32
             });
         }
 
-        private static readonly int SignalW = unchecked((int) 0xdeadbeaf);
-        private static readonly int SignalL = unchecked((int)0x12345678);
+        private const int SignalW = unchecked((int)0xdeadbeaf);
+        private const int SignalL = unchecked((int)0x12345678);
 
         public void Signal(DispatcherPriority prio)
         {
diff --git a/src/tools/Avalonia.Designer.HostApp/Avalonia.Designer.HostApp.csproj b/src/tools/Avalonia.Designer.HostApp/Avalonia.Designer.HostApp.csproj
index dadef1cb9c..0c0fe5b921 100644
--- a/src/tools/Avalonia.Designer.HostApp/Avalonia.Designer.HostApp.csproj
+++ b/src/tools/Avalonia.Designer.HostApp/Avalonia.Designer.HostApp.csproj
@@ -3,6 +3,10 @@
     <OutputType>Exe</OutputType>
     <TargetFrameworks>net461;netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
+  <!--Disable Net Perf. analyzer for submodule to avoid commit issue -->
+  <PropertyGroup>
+    <EnableNETAnalyzers>false</EnableNETAnalyzers>
+  </PropertyGroup>  
   <ItemGroup>
     <ProjectReference Include="..\..\Avalonia.DesignerSupport\Avalonia.DesignerSupport.csproj" />
     <ProjectReference Include="..\..\Markup\Avalonia.Markup.Xaml\Avalonia.Markup.Xaml.csproj" />
diff --git a/tests/Avalonia.Base.UnitTests/VisualTree/MockRenderInterface.cs b/tests/Avalonia.Base.UnitTests/VisualTree/MockRenderInterface.cs
index 1f0b82b465..26a1ab88c7 100644
--- a/tests/Avalonia.Base.UnitTests/VisualTree/MockRenderInterface.cs
+++ b/tests/Avalonia.Base.UnitTests/VisualTree/MockRenderInterface.cs
@@ -235,7 +235,7 @@ namespace Avalonia.Base.UnitTests.VisualTree
 
                 public bool FillContains(Point point)
                 {
-                    // Use the algorithm from http://www.blackpawn.com/texts/pointinpoly/default.html
+                    // Use the algorithm from https://www.blackpawn.com/texts/pointinpoly/default.html
                     // to determine if the point is in the geometry (since it will always be convex in this situation)
                     for (int i = 0; i < points.Count; i++)
                     {
diff --git a/tests/Avalonia.UnitTests/MockStreamGeometryImpl.cs b/tests/Avalonia.UnitTests/MockStreamGeometryImpl.cs
index 864e2efbaf..9d039a386e 100644
--- a/tests/Avalonia.UnitTests/MockStreamGeometryImpl.cs
+++ b/tests/Avalonia.UnitTests/MockStreamGeometryImpl.cs
@@ -148,7 +148,7 @@ namespace Avalonia.UnitTests
 
             public bool FillContains(Point point)
             {
-                // Use the algorithm from http://www.blackpawn.com/texts/pointinpoly/default.html
+                // Use the algorithm from https://www.blackpawn.com/texts/pointinpoly/default.html
                 // to determine if the point is in the geometry (since it will always be convex in this situation)
                 for (int i = 0; i < points.Count; i++)
                 {