diff --git a/Terminal.Gui/View/View.Content.cs b/Terminal.Gui/View/View.Content.cs
index 08443a851..131dd90ba 100644
--- a/Terminal.Gui/View/View.Content.cs
+++ b/Terminal.Gui/View/View.Content.cs
@@ -1,4 +1,5 @@
-namespace Terminal.Gui;
+#nullable enable
+namespace Terminal.Gui;
 
 public partial class View
 {
diff --git a/Terminal.Gui/View/View.Cursor.cs b/Terminal.Gui/View/View.Cursor.cs
index bdba7d85f..700398526 100644
--- a/Terminal.Gui/View/View.Cursor.cs
+++ b/Terminal.Gui/View/View.Cursor.cs
@@ -1,3 +1,4 @@
+#nullable enable
 namespace Terminal.Gui;
 
 public partial class View
diff --git a/Terminal.Gui/View/View.Diagnostics.cs b/Terminal.Gui/View/View.Diagnostics.cs
index c7ac7b851..6e5797e26 100644
--- a/Terminal.Gui/View/View.Diagnostics.cs
+++ b/Terminal.Gui/View/View.Diagnostics.cs
@@ -1,6 +1,4 @@
-
-
-
+#nullable enable
 namespace Terminal.Gui;
 
 /// <summary>Enables diagnostic functions for <see cref="View"/>.</summary>
diff --git a/Terminal.Gui/View/View.Keyboard.cs b/Terminal.Gui/View/View.Keyboard.cs
index 7a7fd35c5..f5b35803d 100644
--- a/Terminal.Gui/View/View.Keyboard.cs
+++ b/Terminal.Gui/View/View.Keyboard.cs
@@ -1,4 +1,5 @@
-using System.ComponentModel;
+#nullable enable
+using System.ComponentModel;
 using System.Diagnostics;
 
 namespace Terminal.Gui;
@@ -50,7 +51,7 @@ public partial class View  // Keyboard APIs
     public event EventHandler<KeyChangedEventArgs> HotKeyChanged;
 
     private Key _hotKey = new ();
-    private void TitleTextFormatter_HotKeyChanged (object sender, KeyChangedEventArgs e) { HotKeyChanged?.Invoke (this, e); }
+    private void TitleTextFormatter_HotKeyChanged (object? sender, KeyChangedEventArgs e) { HotKeyChanged?.Invoke (this, e); }
 
     /// <summary>
     ///     Gets or sets the hot key defined for this view. Pressing the hot key on the keyboard while this view has focus will
@@ -131,7 +132,7 @@ public partial class View  // Keyboard APIs
     /// <param name="context">Arbitrary context that can be associated with this key binding.</param>
     /// <returns><see langword="true"/> if the HotKey bindings were added.</returns>
     /// <exception cref="ArgumentException"></exception>
-    public virtual bool AddKeyBindingsForHotKey (Key prevHotKey, Key hotKey, [CanBeNull] object context = null)
+    public virtual bool AddKeyBindingsForHotKey (Key prevHotKey, Key hotKey, object? context = null)
     {
         if (_hotKey == hotKey)
         {
@@ -657,7 +658,7 @@ public partial class View  // Keyboard APIs
     /// <param name="key">The key to test.</param>
     /// <param name="boundView">Returns the view the key is bound to.</param>
     /// <returns></returns>
-    public bool IsHotKeyKeyBound (Key key, out View boundView)
+    public bool IsHotKeyKeyBound (Key key, out View? boundView)
     {
         // recurse through the subviews to find the views that has the key bound
         boundView = null;
@@ -683,7 +684,7 @@ public partial class View  // Keyboard APIs
     ///     Invoked when a key is pressed that may be mapped to a key binding. Set <see cref="Key.Handled"/> to true to
     ///     stop the key from being processed by other views.
     /// </summary>
-    public event EventHandler<Key> InvokingKeyBindings;
+    public event EventHandler<Key>? InvokingKeyBindings;
 
     /// <summary>
     ///     Invokes any binding that is registered on this <see cref="View"/> and matches the <paramref name="key"/>
@@ -719,7 +720,7 @@ public partial class View  // Keyboard APIs
         // TODO: This is a "prototype" debug check. It may be too annoying vs. useful.
         // Scour the bindings up our View hierarchy
         // to ensure that the key is not already bound to a different set of commands.
-        if (SuperView?.IsHotKeyKeyBound (key, out View previouslyBoundView) ?? false)
+        if (SuperView?.IsHotKeyKeyBound (key, out View? previouslyBoundView) ?? false)
         {
             Debug.WriteLine ($"WARNING: InvokeKeyBindings ({key}) - A subview or peer has bound this Key and will not see it: {previouslyBoundView}.");
         }
@@ -763,7 +764,7 @@ public partial class View  // Keyboard APIs
     ///     <see langword="true"/> if the command was invoked the command was handled.
     ///     <see langword="false"/> if the command was invoked and the command was not handled.
     /// </returns>
-    public bool? InvokeCommands (Command [] commands, [CanBeNull] Key key = null, [CanBeNull] KeyBinding? keyBinding = null)
+    public bool? InvokeCommands (Command [] commands, Key? key = null, KeyBinding? keyBinding = null)
     {
         bool? toReturn = null;
 
@@ -798,9 +799,9 @@ public partial class View  // Keyboard APIs
     ///     <see langword="null"/> if no command was found. <see langword="true"/> if the command was invoked, and it
     ///     handled the command. <see langword="false"/> if the command was invoked, and it did not handle the command.
     /// </returns>
-    public bool? InvokeCommand (Command command, [CanBeNull] Key key = null, [CanBeNull] KeyBinding? keyBinding = null)
+    public bool? InvokeCommand (Command command, Key? key = null, KeyBinding? keyBinding = null)
     {
-        if (CommandImplementations.TryGetValue (command, out Func<CommandContext, bool?> implementation))
+        if (CommandImplementations.TryGetValue (command, out Func<CommandContext, bool?>? implementation))
         {
             var context = new CommandContext (command, key, keyBinding); // Create the context here
             return implementation (context);
diff --git a/Terminal.Gui/View/View.Mouse.cs b/Terminal.Gui/View/View.Mouse.cs
index 302a3346d..b66c07fe3 100644
--- a/Terminal.Gui/View/View.Mouse.cs
+++ b/Terminal.Gui/View/View.Mouse.cs
@@ -1,17 +1,17 @@
-using System.ComponentModel;
+#nullable enable
+using System.ComponentModel;
 
 namespace Terminal.Gui;
 
 public partial class View // Mouse APIs
 {
-    [CanBeNull]
-    private ColorScheme _savedHighlightColorScheme;
+    private ColorScheme? _savedHighlightColorScheme;
 
     /// <summary>
     ///     Fired when the view is highlighted. Set <see cref="CancelEventArgs.Cancel"/> to <see langword="true"/>
     ///     to implement a custom highlight scheme or prevent the view from being highlighted.
     /// </summary>
-    public event EventHandler<CancelEventArgs<HighlightStyle>> Highlight;
+    public event EventHandler<CancelEventArgs<HighlightStyle>>? Highlight;
 
     /// <summary>
     ///     Gets or sets whether the <see cref="View"/> will be highlighted visually while the mouse button is
@@ -29,10 +29,10 @@ public partial class View // Mouse APIs
     ///         The coordinates are relative to <see cref="View.Viewport"/>.
     ///     </para>
     /// </remarks>
-    public event EventHandler<MouseEventEventArgs> MouseClick;
+    public event EventHandler<MouseEventEventArgs>? MouseClick;
 
     /// <summary>Event fired when the mouse moves into the View's <see cref="Viewport"/>.</summary>
-    public event EventHandler<MouseEventEventArgs> MouseEnter;
+    public event EventHandler<MouseEventEventArgs>? MouseEnter;
 
     /// <summary>Event fired when a mouse event occurs.</summary>
     /// <remarks>
@@ -40,10 +40,10 @@ public partial class View // Mouse APIs
     ///         The coordinates are relative to <see cref="View.Viewport"/>.
     ///     </para>
     /// </remarks>
-    public event EventHandler<MouseEventEventArgs> MouseEvent;
+    public event EventHandler<MouseEventEventArgs>? MouseEvent;
 
     /// <summary>Event fired when the mouse leaves the View's <see cref="Viewport"/>.</summary>
-    public event EventHandler<MouseEventEventArgs> MouseLeave;
+    public event EventHandler<MouseEventEventArgs>? MouseLeave;
 
     /// <summary>
     ///     Processes a <see cref="MouseEvent"/>. This method is called by <see cref="Application.OnMouseEvent"/> when a mouse
diff --git a/UnitTests/View/Navigation/EnabledTests.cs b/UnitTests/View/Navigation/EnabledTests.cs
index f909fe924..24bb0c206 100644
--- a/UnitTests/View/Navigation/EnabledTests.cs
+++ b/UnitTests/View/Navigation/EnabledTests.cs
@@ -2,7 +2,7 @@
 
 namespace Terminal.Gui.ViewTests;
 
-public class EnabledTests (ITestOutputHelper _output) : TestsAllViews
+public class EnabledTests () : TestsAllViews
 {
     [Fact]
     public void Enabled_False_Leaves ()
diff --git a/UnitTests/View/Navigation/RestoreFocusTests.cs b/UnitTests/View/Navigation/RestoreFocusTests.cs
index 4fe26722e..12cd0f58b 100644
--- a/UnitTests/View/Navigation/RestoreFocusTests.cs
+++ b/UnitTests/View/Navigation/RestoreFocusTests.cs
@@ -2,7 +2,7 @@
 
 namespace Terminal.Gui.ViewTests;
 
-public class RestoreFocusTests (ITestOutputHelper _output) : TestsAllViews
+public class RestoreFocusTests () : TestsAllViews
 {
     [Fact]
     public void RestoreFocus_Restores ()
diff --git a/UnitTests/View/Navigation/VisibleTests.cs b/UnitTests/View/Navigation/VisibleTests.cs
index fa9d30f72..e4a1e102b 100644
--- a/UnitTests/View/Navigation/VisibleTests.cs
+++ b/UnitTests/View/Navigation/VisibleTests.cs
@@ -2,7 +2,7 @@
 
 namespace Terminal.Gui.ViewTests;
 
-public class VisibleTests (ITestOutputHelper _output) : TestsAllViews
+public class VisibleTests () : TestsAllViews
 {
     [Fact]
     public void Visible_False_Leaves ()