fix: Address review

src/Avalonia.Base/Input/AccessKeyHandler.cs

@@ -24,7 +24,7 @@ namespace Avalonia.Input
         /// <summary>
         /// The registered access keys.
         /// </summary>
-        private readonly List<Tuple<string, IInputElement>> _registered = new List<Tuple<string, IInputElement>>();
+        private readonly List<(string AccessKey, IInputElement Element)> _registered = new();
 
         /// <summary>
         /// The window to which the handler belongs.
@@ -109,12 +109,12 @@ namespace Avalonia.Input
         {
             var existing = _registered.FirstOrDefault(x => x.Item2 == element);
 
-            if (existing != null)
+            if (existing != default)
             {
                 _registered.Remove(existing);
             }
 
-            _registered.Add(Tuple.Create(accessKey.ToString(CultureInfo.InvariantCulture).ToUpperInvariant(), element));
+            _registered.Add((accessKey.ToString().ToUpperInvariant(), element));
         }
 
         /// <summary>
@@ -144,7 +144,7 @@ namespace Avalonia.Input
                 {
                     // TODO: Use FocusScopes to store the current element and restore it when context menu is closed.
                     // Save currently focused input element.
-                    _restoreFocusElement = FocusManager.Instance?.Current;                    
+                    _restoreFocusElement = FocusManager.Instance?.Current;
 
                     // When Alt is pressed without a main menu, or with a closed main menu, show
                     // access key markers in the window (i.e. "_File").
@@ -183,8 +183,9 @@ namespace Avalonia.Input
                 // find all controls who have registered that access key.
                 var text = e.Key.ToString();
                 var matches = _registered
-                    .Where(x => string.Equals( x.Item1 , text, StringComparison.OrdinalIgnoreCase) && ((Visual)x.Item2).IsEffectivelyVisible)
-                    .Select(x => x.Item2);
+                    .Where(x => x.Element.IsEffectivelyVisible 
+                        && string.Equals(x.AccessKey , text, StringComparison.OrdinalIgnoreCase) )
+                    .Select(x => x.Element);
 
                 // If the menu is open, only match controls in the menu's visual tree.
                 if (menuIsOpen)
@@ -195,7 +196,7 @@ namespace Avalonia.Input
                 var match = matches.FirstOrDefault();
 
                 // If there was a match, raise the AccessKeyPressed event on it.
-                if (match != null)
+                if (match is not null)
                 {
                     match.RaiseEvent(new RoutedEventArgs(AccessKeyPressedEvent));
                     e.Handled = true;

src/Avalonia.Controls/MenuItemAccessKeyHandler.cs

@@ -88,9 +88,10 @@ namespace Avalonia.Controls
         {
             if (!string.IsNullOrWhiteSpace(e.Text))
             {
-                var text = e.Text.ToUpperInvariant();
+                var text = e.Text;
                 var focus = _registered
-                    .FirstOrDefault(x => x.Element.IsEffectivelyVisible && x.Item1 == text).Element;
+                    .FirstOrDefault(x => x.Element.IsEffectivelyVisible 
+                        && string.Equals(x.AccessKey, text, StringComparison.OrdinalIgnoreCase)).Element;
 
                 focus?.RaiseEvent(new RoutedEventArgs(AccessKeyHandler.AccessKeyPressedEvent));