Fixes Code Analysis issues for C# templates

templates/csharp/app-mvvm/Program.cs

@@ -6,7 +6,7 @@
 
 namespace AvaloniaAppTemplate;
 
-class Program
+sealed class Program
 {
     // Initialization code. Don't use any Avalonia, third-party APIs or any
     // SynchronizationContext-reliant code before AppMain is called: things aren't initialized

templates/csharp/app-mvvm/ViewModels/MainWindowViewModel.cs

@@ -6,5 +6,7 @@ public partial class MainWindowViewModel : ViewModelBase
 public class MainWindowViewModel : ViewModelBase
 #endif
 {
+#pragma warning disable CA1822 // Mark members as static
     public string Greeting => "Welcome to Avalonia!";
+#pragma warning restore CA1822 // Mark members as static
 }

templates/csharp/xplat/AvaloniaTest.Browser/Program.cs

@@ -7,9 +7,9 @@
 
 [assembly: SupportedOSPlatform("browser")]
 
-internal partial class Program
+internal sealed partial class Program
 {
-    private static async Task Main(string[] args) => await BuildAvaloniaApp()
+    private static Task Main(string[] args) => BuildAvaloniaApp()
             .WithInterFont()
             .UseReactiveUI()
             .StartBrowserAppAsync("out");

templates/csharp/xplat/AvaloniaTest.Desktop/Program.cs

@@ -4,7 +4,7 @@
 
 namespace AvaloniaTest.Desktop;
 
-class Program
+sealed class Program
 {
     // Initialization code. Don't use any Avalonia, third-party APIs or any
     // SynchronizationContext-reliant code before AppMain is called: things aren't initialized

templates/csharp/xplat/AvaloniaTest.iOS/AppDelegate.cs

@@ -12,7 +12,9 @@ namespace AvaloniaTest.iOS;
 // User Interface of the application, as well as listening (and optionally responding) to 
 // application events from iOS.
 [Register("AppDelegate")]
+#pragma warning disable CA1711 // Identifiers should not have incorrect suffix
 public partial class AppDelegate : AvaloniaAppDelegate<App>
+#pragma warning restore CA1711 // Identifiers should not have incorrect suffix
 {
     protected override AppBuilder CustomizeAppBuilder(AppBuilder builder)
     {

templates/csharp/xplat/AvaloniaTest/ViewLocator.cs

@@ -8,22 +8,22 @@ namespace AvaloniaTest;
 public class ViewLocator : IDataTemplate
 {
 #if (AvaloniaStableChosen)
-    public IControl Build(object data)
+    public IControl Build(object param)
 #else
-    public Control Build(object data)
+    public Control? Build(object param)
 #endif
     {
-        if (data is null)
+        if (param is null)
             return null;
 
-        var name = data.GetType().FullName!.Replace("ViewModel", "View");
+        var name = param.GetType().FullName!.Replace("ViewModel", "View", StringComparison.Ordinal);
         var type = Type.GetType(name);
 
         if (type != null)
         {
             return (Control)Activator.CreateInstance(type)!;
         }
-        
+
         return new TextBlock { Text = name };
     }
 

templates/csharp/xplat/AvaloniaTest/ViewModels/MainViewModel.cs

@@ -2,5 +2,7 @@
 
 public class MainViewModel : ViewModelBase
 {
+#pragma warning disable CA1822 // Mark members as static
     public string Greeting => "Welcome to Avalonia!";
+#pragma warning restore CA1822 // Mark members as static
 }