Update C# templates to introduce file scoped namespaces (#4911)

* Update C# templates to introduce file scoped namespaces

* introduce file scoped namespaces to dev/VSIX/Extension and dev/VSIX/Shared folders as well

* resolve comments:
1. mark all classes 'partial'
2. align the MainWindow to be an empty Grid without the Button and handler

* Enable Mica

* remove mica for non-window level

* 1. Remove 'Button' from C++ templates
2. Remove Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" from Blank Page item template

* 1. Remove 'this.' and change 'm_' to '_'
2. Add empty line between functions

* revert file scoped namesapce for VSPackages.cs and WizardImplementation.cs

---------

Co-authored-by: Haonan Tang (from Dev Box) <haonantang@microsoft.com>

Author: haonanttt

dev/VSIX/Extension/Cs/Dev17/VSPackage.cs

@@ -28,7 +28,7 @@ namespace WindowsAppSDK.Cs.Extension
     /// </remarks>
     [PackageRegistration(UseManagedResourcesOnly = true, AllowsBackgroundLoading = true)]
     [Guid(VSPackage.PackageGuidString)]
-    public sealed class VSPackage : AsyncPackage
+    public sealed partial class VSPackage : AsyncPackage
     {
         /// <summary>
         /// VSPackage GUID string.
@@ -55,4 +55,4 @@ protected override async Task InitializeAsync(CancellationToken cancellationToke
 
         #endregion
     }
-}
+}

dev/VSIX/ItemTemplates/Desktop/CSharp/BlankWindow/BlankWindow.xaml

@@ -9,6 +9,10 @@
     mc:Ignorable="d"
     Title="$itemname$">
 
+    <Window.SystemBackdrop>
+        <MicaBackdrop />
+    </Window.SystemBackdrop>
+
     <Grid>
 
     </Grid>

dev/VSIX/ItemTemplates/Desktop/CSharp/BlankWindow/BlankWindow.xaml.cs

@@ -16,16 +16,15 @@
 // To learn more about WinUI, the WinUI project structure,
 // and more about our project templates, see: http://aka.ms/winui-project-info.
 
-namespace $rootnamespace$
+namespace $rootnamespace$;
+
+/// <summary>
+/// An empty window that can be used on its own or navigated to within a Frame.
+/// </summary>
+public sealed partial class $safeitemname$ : Window
 {
-    /// <summary>
-    /// An empty window that can be used on its own or navigated to within a Frame.
-    /// </summary>
-    public sealed partial class $safeitemname$ : Window
+    public $safeitemname$()
     {
-        public $safeitemname$()
-        {
-            this.InitializeComponent();
-        }
+        InitializeComponent();
     }
 }

dev/VSIX/ItemTemplates/Desktop/CppWinRT/BlankWindow/BlankWindow.cpp

@@ -21,9 +21,4 @@ namespace winrt::$rootnamespace$::implementation
     {
         throw hresult_not_implemented();
     }
-
-    void $safeitemname$::myButton_Click(IInspectable const&, RoutedEventArgs const&)
-    {
-        myButton().Content(box_value(L"Clicked"));
-    }
 }

dev/VSIX/ItemTemplates/Desktop/CppWinRT/BlankWindow/BlankWindow.h

@@ -14,8 +14,6 @@ namespace winrt::$rootnamespace$::implementation
 
         int32_t MyProperty();
         void MyProperty(int32_t value);
-
-        void myButton_Click(IInspectable const& sender, Microsoft::UI::Xaml::RoutedEventArgs const& args);
     };
 }
 

dev/VSIX/ItemTemplates/Desktop/CppWinRT/BlankWindow/BlankWindow.xaml

@@ -9,7 +9,7 @@
     mc:Ignorable="d"
     Title="$itemname$">
 
-    <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center">
-        <Button x:Name="myButton" Click="myButton_Click">Click Me</Button>
-    </StackPanel>
+    <Grid>
+
+    </Grid>
 </Window>

dev/VSIX/ItemTemplates/Neutral/CSharp/BlankPage/BlankPage.xaml

@@ -6,8 +6,7 @@
     xmlns:local="using:$rootnamespace$"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    mc:Ignorable="d"
-    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+    mc:Ignorable="d">
 
     <Grid>
 

dev/VSIX/ItemTemplates/Neutral/CSharp/BlankPage/BlankPage.xaml.cs

@@ -16,16 +16,15 @@
 // To learn more about WinUI, the WinUI project structure,
 // and more about our project templates, see: http://aka.ms/winui-project-info.
 
-namespace $rootnamespace$
+namespace $rootnamespace$;
+
+/// <summary>
+/// An empty page that can be used on its own or navigated to within a Frame.
+/// </summary>
+public sealed partial class $safeitemname$ : Page
 {
-    /// <summary>
-    /// An empty page that can be used on its own or navigated to within a Frame.
-    /// </summary>
-    public sealed partial class $safeitemname$ : Page
+    public $safeitemname$()
     {
-        public $safeitemname$()
-        {
-            this.InitializeComponent();
-        }
+        InitializeComponent();
     }
 }

dev/VSIX/ItemTemplates/Neutral/CSharp/TemplatedControl/CustomControl.cs

@@ -12,13 +12,12 @@
 // To learn more about WinUI, the WinUI project structure,
 // and more about our project templates, see: http://aka.ms/winui-project-info.
 
-namespace $rootnamespace$
+namespace $rootnamespace$;
+
+public sealed partial class $safeitemname$ : Control
 {
-    public sealed class $safeitemname$ : Control
+    public $safeitemname$()
     {
-        public $safeitemname$()
-        {
-            this.DefaultStyleKey = typeof($safeitemname$);
-        }
+        DefaultStyleKey = typeof($safeitemname$);
     }
 }

dev/VSIX/ItemTemplates/Neutral/CSharp/UserControl/UserControl.xaml.cs

@@ -16,13 +16,12 @@
 // To learn more about WinUI, the WinUI project structure,
 // and more about our project templates, see: http://aka.ms/winui-project-info.
 
-namespace $rootnamespace$
+namespace $rootnamespace$;
+
+public sealed partial class $safeitemname$ : UserControl
 {
-    public sealed partial class $safeitemname$ : UserControl
+    public $safeitemname$()
     {
-        public $safeitemname$()
-        {
-            this.InitializeComponent();
-        }
+        InitializeComponent();
     }
 }