Refactor PropertyGrid UI, converters, and solution setup

- Improved PropertyGrid.axaml formatting and control styles; ensured spinner buttons are always visible and ColorPicker layouts are flexible; disabled horizontal scrolling in property list.
- Reformatted property editors and group/category display for clarity.
- Made all value converters sealed, added XML docs, and updated ConvertBack to throw NotImplementedException where unsupported.
- Enhanced search logic to use StringComparison.OrdinalIgnoreCase.
- Minor code style fixes (e.g., char literals for string checks).
- Removed default value assignment for _useProxy in AdvancedConfiguration.cs.
- Updated Program.cs in examples to use sealed Program classes.
- Added PropertyGrid.slnx to organize solution and projects.

Avalonia.PropertyGrid/Controls/PropertyGrid.axaml

@@ -10,6 +10,20 @@
         </Border>
     </Design.PreviewWith>
 
+    <!-- Force NumericUpDown spinner buttons to always be visible -->
+    <Style Selector="controls|PropertyGrid NumericUpDown">
+        <Setter Property="AllowSpin" Value="True" />
+        <Setter Property="ShowButtonSpinner" Value="True" />
+        <Setter Property="ButtonSpinnerLocation" Value="Right" />
+    </Style>
+
+    <Style Selector="controls|PropertyGrid NumericUpDown /template/ TextBox#PART_TextBox">
+        <Setter Property="MinWidth" Value="0" />
+    </Style>
+    <Style Selector="controls|PropertyGrid ColorPicker /template/ DropDownButton /template/ PathIcon#DropDownGlyph">
+        <Setter Property="IsVisible" Value="False" />
+    </Style>
+  
     <Style Selector="controls|PropertyGrid">
         <Setter Property="Background" Value="{DynamicResource SystemControlBackgroundAltHighBrush}" />
         <Setter Property="BorderBrush" Value="{DynamicResource SystemControlForegroundBaseMediumLowBrush}" />
@@ -41,7 +55,7 @@
 
                         <!-- Properties List -->
                         <ScrollViewer Grid.Row="1"
-                         HorizontalScrollBarVisibility="Auto"
+                                      HorizontalScrollBarVisibility="Disabled"
                                       VerticalScrollBarVisibility="Auto">
                             <Panel>
                                 <!-- Category View -->
@@ -67,14 +81,14 @@
                                                                 <!-- Right Arrow (collapsed/closed state) -->
                                                                 <Path IsVisible="{Binding !IsExpanded}"
                                                                       Data="M 4,2 L 10,8 L 4,14 Z"
-                                    Fill="White"
+                                                                      Fill="{DynamicResource SystemControlForegroundBaseHighBrush}"
                                                                       Width="12" Height="12"
                                                                       Stretch="Uniform" />
 
                                                                 <!-- Down Arrow (expanded/open state) -->
                                                                 <Path IsVisible="{Binding IsExpanded}"
                                                                       Data="M 2,4 L 8,10 L 14,4 Z"
-                                    Fill="White"
+                                                                      Fill="{DynamicResource SystemControlForegroundBaseHighBrush}"
                                                                       Width="12" Height="12"
                                                                       Stretch="Uniform" />
                                                             </Panel>
@@ -124,7 +138,7 @@
                                                                                           Width="16" Height="16"
                                                                                           Padding="0"
                                                                                           VerticalAlignment="Center">
-                            <Panel>
+                                                                                <Panel >
                                                                                     <!-- Right Arrow (collapsed/closed state) -->
                                                                                     <Path IsVisible="{Binding !IsExpanded}"
                                                                                           Data="M 4,2 L 10,8 L 4,14 Z"
@@ -160,30 +174,30 @@
                                                                             BorderBrush="{DynamicResource SystemControlForegroundBaseMediumLowBrush}"
                                                                             BorderThickness="0,0,0,1">
                                                                         <Grid>
-                          <!-- Color Picker for Color properties with colored background -->
+                                                                          <!-- Color Picker for Color properties -->
-                          <Border Background="{Binding ColorValue, Converter={StaticResource ColorToBrushConverter}}"
-                                  IsVisible="{Binding PropertyType, Converter={StaticResource IsColorTypeConverter}}"
-                                  CornerRadius="4"
-                                  Padding="4">
                                                                           <ColorPicker Color="{Binding ColorValue, Mode=TwoWay}"
+                                                                                       IsVisible="{Binding PropertyType, Converter={StaticResource IsColorTypeConverter}}"
                                                                                        IsEnabled="{Binding !IsReadOnly}"
                                                                                        IsAlphaEnabled="True"
-                                         HorizontalAlignment="Stretch">
+                                                                                       HorizontalAlignment="Stretch"
+                                                                                       VerticalAlignment="Center"
+                                                                                       Width="{Binding $parent[Grid].Bounds.Width}">
                                                                             <ColorPicker.Styles>
                                                                               <Style Selector="ColorPicker">
-                                  <Setter Property="MaxWidth" Value="{x:Static sys:Double.PositiveInfinity}" />
+                                                                                <Setter Property="MinWidth" Value="0" />
+                                                                                <Setter Property="MaxWidth" Value="999999" />
+                                                                              </Style>
+                                                                              <Style Selector="ColorPicker > :is(Control)">
+                                                                                <Setter Property="HorizontalAlignment" Value="Stretch" />
                                                                               </Style>
                                                                             </ColorPicker.Styles>
                                                                           </ColorPicker>
-                          </Border>
 
                                                                             <!-- NumericUpDown for numeric properties -->
                                                                             <NumericUpDown Value="{Binding NumericValue, Mode=TwoWay}"
                                                                                            IsVisible="{Binding PropertyType, Converter={StaticResource IsNumericTypeConverter}}"
                                                                                            IsReadOnly="{Binding IsReadOnly}"
                                                                                            FormatString="{Binding PropertyType, Converter={StaticResource NumericFormatConverter}}"
-                                         AllowSpin="True"
-                                         ShowButtonSpinner="True"
                                                                                            HorizontalAlignment="Stretch" />
 
                                                                             <!-- CheckBox for boolean properties -->
@@ -281,30 +295,30 @@
                                                             BorderBrush="{DynamicResource SystemControlForegroundBaseMediumLowBrush}"
                                                             BorderThickness="0,0,0,1">
                                                         <Grid>
-                              <!-- ColorPicker for color properties with colored background -->
+                                                          <!-- Color Picker for Color properties -->
-                              <Border Background="{Binding ColorValue, Converter={StaticResource ColorToBrushConverter}}"
-                                      IsVisible="{Binding PropertyType, Converter={StaticResource IsColorTypeConverter}}"
-                                      CornerRadius="4"
-                                      Padding="4">
                                                           <ColorPicker Color="{Binding ColorValue, Mode=TwoWay}"
+                                                                       IsVisible="{Binding PropertyType, Converter={StaticResource IsColorTypeConverter}}"
                                                                        IsEnabled="{Binding !IsReadOnly}"
-                                            HorizontalAlignment="Stretch">
+                                                                       IsAlphaEnabled="True"
+                                                                       HorizontalAlignment="Stretch"
+                                                                       VerticalAlignment="Center"
+                                                                       Width="{Binding $parent[Grid].Bounds.Width}">
                                                             <ColorPicker.Styles>
                                                               <Style Selector="ColorPicker">
-                                      <Setter Property="Width" Value="{x:Static sys:Double.PositiveInfinity}" />
+                                                                <Setter Property="MinWidth" Value="0" />
+                                                                <Setter Property="MaxWidth" Value="999999" />
+                                                              </Style>
+                                                              <Style Selector="ColorPicker > :is(Control)">
                                                                 <Setter Property="HorizontalAlignment" Value="Stretch" />
                                                               </Style>
                                                             </ColorPicker.Styles>
                                                           </ColorPicker>
-                              </Border>
 
                                                             <!-- NumericUpDown for numeric properties -->
                                                             <NumericUpDown Value="{Binding NumericValue, Mode=TwoWay}"
                                                                            IsVisible="{Binding PropertyType, Converter={StaticResource IsNumericTypeConverter}}"
                                                                            IsReadOnly="{Binding IsReadOnly}"
                                                                            FormatString="{Binding PropertyType, Converter={StaticResource NumericFormatConverter}}"
-                                             AllowSpin="True"
-                                             ShowButtonSpinner="True"
                                                                            HorizontalAlignment="Stretch" />
 
                                                             <!-- CheckBox for boolean properties -->

Avalonia.PropertyGrid/Controls/PropertyGrid.axaml.cs

@@ -288,11 +288,10 @@ public class PropertyGrid : TemplatedControl
         // Apply search filter
         if (!string.IsNullOrWhiteSpace(_searchText))
         {
-            var searchLower = _searchText.ToLowerInvariant();
             filtered = filtered.Where(p =>
-                p.DisplayName.ToLowerInvariant().Contains(searchLower) ||
+                p.DisplayName.Contains(_searchText, StringComparison.OrdinalIgnoreCase) ||
-                (p.Category?.ToLowerInvariant().Contains(searchLower) ?? false) ||
+                (p.Category?.Contains(_searchText, StringComparison.OrdinalIgnoreCase) ?? false) ||
-                (p.Description?.ToLowerInvariant().Contains(searchLower) ?? false));
+                (p.Description?.Contains(_searchText, StringComparison.OrdinalIgnoreCase) ?? false));
         }
 
         // Populate flat list

Avalonia.PropertyGrid/Converters/ColorToBrushConverter.cs

@@ -8,8 +8,16 @@ namespace Avalonia.PropertyGrid.Controls;
 /// <summary>
 /// Converts an Avalonia.Media.Color to a SolidColorBrush
 /// </summary>
-public class ColorToBrushConverter : IValueConverter
+public sealed class ColorToBrushConverter : IValueConverter
 {
+    /// <summary>
+    /// Converts a Color to a SolidColorBrush.
+    /// </summary>
+    /// <param name="value">The Color value to convert.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>A SolidColorBrush with the specified color.</returns>
     public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Color color)
@@ -21,9 +29,17 @@ public class ColorToBrushConverter : IValueConverter
         return new SolidColorBrush(Colors.Transparent);
     }
 
+    /// <summary>
+    /// Converts a SolidColorBrush back to a Color.
+    /// </summary>
+    /// <param name="value">The SolidColorBrush value to convert back.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>The Color from the brush.</returns>
     public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
-        if (value is SolidColorBrush brush && brush.Color != null)
+        if (value is SolidColorBrush brush)
         {
             return brush.Color;
         }

Avalonia.PropertyGrid/Converters/NegateBoolConverter.cs

@@ -7,8 +7,16 @@ namespace Avalonia.PropertyGrid.Controls;
 /// <summary>
 /// Converts boolean value to its negation for two-way binding
 /// </summary>
-public class NegateBoolConverter : IValueConverter
+public sealed class NegateBoolConverter : IValueConverter
 {
+    /// <summary>
+    /// Converts a boolean value to its negation.
+    /// </summary>
+    /// <param name="value">The boolean value to convert.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>The negated boolean value.</returns>
     public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is bool boolValue)
@@ -18,6 +26,14 @@ public class NegateBoolConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Converts a boolean value back to its negation (two-way binding).
+    /// </summary>
+    /// <param name="value">The boolean value to convert back.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>The negated boolean value.</returns>
     public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is bool boolValue)

Avalonia.PropertyGrid/Converters/NumericFormatConverter.cs

@@ -7,8 +7,16 @@ namespace Avalonia.PropertyGrid.Controls;
 /// <summary>
 /// Converts PropertyType to appropriate numeric format string
 /// </summary>
-public class NumericFormatConverter : IValueConverter
+public sealed class NumericFormatConverter : IValueConverter
 {
+    /// <summary>
+    /// Converts a Type to an appropriate numeric format string.
+    /// </summary>
+    /// <param name="value">The Type to convert.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>A format string like "N2" for floating point or "N0" for integers.</returns>
     public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -26,6 +34,15 @@ public class NumericFormatConverter : IValueConverter
         return "N0";
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <param name="value">The value to convert back.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>Throws NotImplementedException.</returns>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();

Avalonia.PropertyGrid/Converters/PropertyGridConverters.cs

@@ -7,7 +7,7 @@ namespace Avalonia.PropertyGrid.Controls;
 /// <summary>
 /// Converts indent level to left margin
 /// </summary>
-public class IndentToMarginConverter : IValueConverter
+public sealed class IndentToMarginConverter : IValueConverter
 {
     /// <summary>
     /// Converts indent level to left margin.
@@ -33,7 +33,7 @@ public class IndentToMarginConverter : IValueConverter
 /// <summary>
 /// Converts enum type to list of enum values
 /// </summary>
-public class EnumValuesConverter : IValueConverter
+public sealed class EnumValuesConverter : IValueConverter
 {
     /// <summary>
     /// Converts an enum type to an array of its values.
@@ -59,8 +59,16 @@ public class EnumValuesConverter : IValueConverter
 /// <summary>
 /// Checks if a type is an enum
 /// </summary>
-public class IsEnumConverter : IValueConverter
+public sealed class IsEnumConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the provided type is an enum.
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type is an enum, otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -70,6 +78,10 @@ public class IsEnumConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
@@ -79,8 +91,16 @@ public class IsEnumConverter : IValueConverter
 /// <summary>
 /// Checks if a type is a simple type (string, number, bool, etc.)
 /// </summary>
-public class IsSimpleTypeConverter : IValueConverter
+public sealed class IsSimpleTypeConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the provided type is a simple type like string, number, DateTime, etc.
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type is a simple type, otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -96,6 +116,10 @@ public class IsSimpleTypeConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
@@ -105,8 +129,16 @@ public class IsSimpleTypeConverter : IValueConverter
 /// <summary>
 /// Checks if a type matches the specified type name
 /// </summary>
-public class TypeToBoolConverter : IValueConverter
+public sealed class TypeToBoolConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the type's name matches the specified parameter string.
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">The type name to match against.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type name matches, otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type && parameter is string typeName)
@@ -116,6 +148,10 @@ public class TypeToBoolConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
@@ -125,8 +161,16 @@ public class TypeToBoolConverter : IValueConverter
 /// <summary>
 /// Converts Color to/from hex string representation
 /// </summary>
-public class ColorToStringConverter : IValueConverter
+public sealed class ColorToStringConverter : IValueConverter
 {
+    /// <summary>
+    /// Converts a Color to a hex string representation.
+    /// </summary>
+    /// <param name="value">The Color to convert.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>A hex string representation of the color (e.g., "#AARRGGBB").</returns>
     public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Media.Color color)
@@ -136,6 +180,14 @@ public class ColorToStringConverter : IValueConverter
         return value?.ToString();
     }
 
+    /// <summary>
+    /// Converts a hex string back to a Color.
+    /// </summary>
+    /// <param name="value">The hex string to convert.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>The parsed Color, or Black if parsing fails.</returns>
     public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is string hexString && !string.IsNullOrWhiteSpace(hexString))
@@ -143,7 +195,7 @@ public class ColorToStringConverter : IValueConverter
             try
             {
                 hexString = hexString.Trim();
-                if (!hexString.StartsWith("#"))
+                if (!hexString.StartsWith('#'))
                     hexString = "#" + hexString;
 
                 return Media.Color.Parse(hexString);
@@ -161,8 +213,16 @@ public class ColorToStringConverter : IValueConverter
 /// <summary>
 /// Checks if a type is Color
 /// </summary>
-public class IsColorTypeConverter : IValueConverter
+public sealed class IsColorTypeConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the provided type is Avalonia.Media.Color.
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional "Invert" parameter to invert the result.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type is Color (or inverted if parameter is "Invert"), otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -187,6 +247,10 @@ public class IsColorTypeConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
@@ -196,8 +260,16 @@ public class IsColorTypeConverter : IValueConverter
 /// <summary>
 /// Checks if a type is numeric
 /// </summary>
-public class IsNumericTypeConverter : IValueConverter
+public sealed class IsNumericTypeConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the provided type is a numeric type (int, long, float, double, decimal, etc.).
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional "Invert" parameter to invert the result.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type is numeric (or inverted if parameter is "Invert"), otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -225,6 +297,10 @@ public class IsNumericTypeConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
@@ -234,8 +310,16 @@ public class IsNumericTypeConverter : IValueConverter
 /// <summary>
 /// Checks if a type is neither Color nor Numeric nor Boolean nor Enum (for fallback TextBox)
 /// </summary>
-public class IsOtherTypeConverter : IValueConverter
+public sealed class IsOtherTypeConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the type is not Color, Numeric, Boolean, or Enum (used for fallback TextBox editor).
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional parameter.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type is not a special type, otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -255,6 +339,10 @@ public class IsOtherTypeConverter : IValueConverter
         return true; // Default to showing TextBox
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
@@ -264,8 +352,16 @@ public class IsOtherTypeConverter : IValueConverter
 /// <summary>
 /// Checks if a type is boolean
 /// </summary>
-public class IsBooleanTypeConverter : IValueConverter
+public sealed class IsBooleanTypeConverter : IValueConverter
 {
+    /// <summary>
+    /// Checks if the provided type is boolean.
+    /// </summary>
+    /// <param name="value">The Type to check.</param>
+    /// <param name="targetType">The target type.</param>
+    /// <param name="parameter">Optional "Invert" parameter to invert the result.</param>
+    /// <param name="culture">Culture information.</param>
+    /// <returns>True if the type is boolean (or inverted if parameter is "Invert"), otherwise false.</returns>
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Type type)
@@ -290,6 +386,10 @@ public class IsBooleanTypeConverter : IValueConverter
         return false;
     }
 
+    /// <summary>
+    /// Not supported for this converter.
+    /// </summary>
+    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
     public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();

Avalonia.PropertyGrid/Editors/PropertyEditors.cs

@@ -266,7 +266,7 @@ public class DateTimeEditor : PropertyEditor
 /// <summary>
 /// Converter for DateTime to DateTimeOffset
 /// </summary>
-internal class DateTimeToDateTimeOffsetConverter : Avalonia.Data.Converters.IValueConverter
+internal sealed class DateTimeToDateTimeOffsetConverter : Avalonia.Data.Converters.IValueConverter
 {
     public object? Convert(object? value, Type targetType, object? parameter, System.Globalization.CultureInfo culture)
     {

Avalonia.PropertyGrid/Models/CategoryGroup.cs

@@ -47,6 +47,10 @@ public class CategoryGroup : INotifyPropertyChanged
     /// </summary>
     public int PropertyCount => Properties.Count;
 
+    /// <summary>
+    /// Raises the PropertyChanged event for the specified property.
+    /// </summary>
+    /// <param name="propertyName">The name of the property that changed.</param>
     protected virtual void OnPropertyChanged(string propertyName)
     {
         PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

Avalonia.PropertyGrid/Models/PropertyItem.cs

@@ -182,7 +182,7 @@ public class PropertyItem : INotifyPropertyChanged
                 try
                 {
                     var hexString = value?.Trim() ?? "";
-                    if (!hexString.StartsWith("#"))
+                    if (!hexString.StartsWith('#'))
                         hexString = "#" + hexString;
 
                     Value = Media.Color.Parse(hexString);

Examples/AdvancedExample/Models/AdvancedConfiguration.cs

@@ -223,7 +223,7 @@ public class NetworkSettings : INotifyPropertyChanged
 {
     private string _hostname = "api.example.com";
     private int _port = 443;
-    private bool _useProxy = false;
+    private bool _useProxy;
     private string _proxyAddress = string.Empty;
 
     [Display(Name = "Hostname", Description = "Server hostname or IP address")]

Examples/AdvancedExample/Program.cs

@@ -3,7 +3,7 @@ using System;
 
 namespace AdvancedExample;
 
-class Program
+sealed class Program
 {
     [STAThread]
     public static void Main(string[] args) => BuildAvaloniaApp()

Examples/QuickStartExample/Program.cs

@@ -3,7 +3,7 @@ using Avalonia;
 
 namespace QuickStartExample;
 
-class Program
+sealed class Program
 {
     [STAThread]
     public static void Main(string[] args) => BuildAvaloniaApp()

PropertyGrid.slnx

@@ -0,0 +1,7 @@
+<Solution>
+  <Folder Name="/Examples/">
+    <Project Path="Examples/AdvancedExample/AdvancedExample.csproj" />
+   <Project Path="Examples/QuickStartExample/QuickStartExample.csproj" />
+  </Folder>
+  <Project Path="Avalonia.PropertyGrid/Avalonia.PropertyGrid.csproj" />
+</Solution>