Use data bindings.

Converters/RadioButtonToStringConverter.cs

@@ -0,0 +1,25 @@
+using System.Globalization;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+
+namespace HellDivers2OneKeyStratagem;
+
+public class RadioButtonToStringConverter : IValueConverter
+{
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is string currentStringValue && parameter is string stringValue)
+            return currentStringValue == stringValue;
+
+        return BindingOperations.DoNothing;
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is bool isChecked && parameter is string stringValue)
+            if (isChecked)
+                return stringValue;
+
+        return BindingOperations.DoNothing;
+    }
+}

Dialogs/InfoWindow.axaml.cs

@@ -39,7 +39,7 @@ public void SetInfo(string info)
 
     private void InfoWindow_OnClosed(object? sender, EventArgs e)
     {
-        _mainWindow.NotifyInfoWindowClosed();
+        MainViewModel.Instance.ShowSpeechInfoWindow = false;
     }
 
     private void Window_OnPointerPressed(object? sender, PointerPressedEventArgs e)

HellDivers2OneKeyStratagem.csproj

@@ -21,6 +21,7 @@
     <PackageReference Include="Avalonia.Fonts.Inter" Version="11.1.0-rc1" />
     <!--Condition below is needed to remove Avalonia.Diagnostics package from build output in Release configuration.-->
     <PackageReference Condition="'$(Configuration)' == 'Debug'" Include="Avalonia.Diagnostics" Version="11.1.0-rc1" />
+    <PackageReference Include="Avalonia.Xaml.Behaviors" Version="11.1.0-rc1" />
     <PackageReference Include="CommunityToolkit.Mvvm" Version="8.2.2" />
     <PackageReference Include="EdgeTTS" Version="1.0.3" />
     <PackageReference Include="GlobalHotKeys.Windows" Version="0.1.0" />