Revert "[Peek] Fix PreviewHandler previewer not visible on first activation (#34991)"

This reverts commit 056fba0dcf.

src/modules/peek/Peek.FilePreviewer/Controls/ShellPreviewHandlerControl.xaml

@@ -13,4 +13,5 @@
     GotFocus="UserControl_GotFocus"
     IsEnabled="False"
     IsTabStop="True"
+    Loaded="UserControl_Loaded"
     mc:Ignorable="d" />

src/modules/peek/Peek.FilePreviewer/Controls/ShellPreviewHandlerControl.xaml.cs

@@ -61,8 +61,6 @@ namespace Peek.FilePreviewer.Controls
 
         partial void OnSourceChanged(IPreviewHandler? value)
         {
-            EnsureContainerHwndCreated();
-
             if (Source != null)
             {
                 UpdatePreviewerTheme();
@@ -84,8 +82,6 @@ namespace Peek.FilePreviewer.Controls
 
         private void OnHandlerVisibilityChanged()
         {
-            EnsureContainerHwndCreated();
-
             if (HandlerVisibility == Visibility.Visible)
             {
                 PInvoke.ShowWindow(containerHwnd, SHOW_WINDOW_CMD.SW_SHOW);
@@ -142,19 +138,8 @@ namespace Peek.FilePreviewer.Controls
             return PInvoke.DefWindowProc(hWnd, msg, wParam, lParam);
         }
 
-        private void EnsureContainerHwndCreated()
+        private void UserControl_Loaded(object sender, RoutedEventArgs e)
         {
-            if (!containerHwnd.IsNull)
-            {
-                return;
-            }
-
-            var peekWindow = new HWND(Win32Interop.GetWindowFromWindowId(XamlRoot?.ContentIslandEnvironment?.AppWindowId ?? default));
-            if (peekWindow.IsNull)
-            {
-                return;
-            }
-
             fixed (char* pContainerClassName = "PeekShellPreviewHandlerContainer")
             {
                 PInvoke.RegisterClass(new WNDCLASSW()
@@ -173,7 +158,7 @@ namespace Peek.FilePreviewer.Controls
                     0, // Y
                     0, // Width
                     0, // Height
-                    peekWindow,
+                    (HWND)Win32Interop.GetWindowFromWindowId(XamlRoot.ContentIslandEnvironment.AppWindowId), // Peek UI window
                     HMENU.Null,
                     HINSTANCE.Null);
 
@@ -184,8 +169,6 @@ namespace Peek.FilePreviewer.Controls
 
         private void UserControl_EffectiveViewportChanged(FrameworkElement sender, EffectiveViewportChangedEventArgs args)
         {
-            EnsureContainerHwndCreated();
-
             var dpi = (float)PInvoke.GetDpiForWindow(containerHwnd) / 96;
 
             // Resize the container window