Change empty icon to use lazy initialization (#20211)

src/Windows/Avalonia.Win32/TrayIconImpl.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Win32
 {
     internal class TrayIconImpl : ITrayIconImpl
     {
-        private static readonly Win32Icon s_emptyIcon;
+        private static Win32Icon? s_emptyIcon;
         private readonly int _uniqueId;
         private static int s_nextUniqueId;
         private static nint s_taskBarMonitor;
@@ -31,13 +31,6 @@ namespace Avalonia.Win32
         private bool _disposedValue;
         private static readonly uint WM_TASKBARCREATED = RegisterWindowMessage("TaskbarCreated");
 
-        static TrayIconImpl()
-        {
-            using var bitmap = new WriteableBitmap(
-                new PixelSize(32, 32), new Vector(96, 96), PixelFormats.Bgra8888, AlphaFormat.Unpremul);
-            s_emptyIcon = new Win32Icon(bitmap);
-        }
-
         internal static void ChangeWindowMessageFilter(IntPtr hWnd)
         {
             ChangeWindowMessageFilterEx(hWnd, WM_TASKBARCREATED, MessageFilterFlag.MSGFLT_ALLOW, IntPtr.Zero);
@@ -145,7 +138,7 @@ namespace Avalonia.Win32
             {
                 iconData.uFlags = NIF.TIP | NIF.MESSAGE | NIF.ICON;
                 iconData.uCallbackMessage = (int)CustomWindowsMessage.WM_TRAYMOUSE;
-                iconData.hIcon = (_iconStale ? newIcon : _icon)?.Handle ?? s_emptyIcon.Handle;
+                iconData.hIcon = (_iconStale ? newIcon : _icon)?.Handle ?? GetOrCreateEmptyIcon().Handle;
                 iconData.szTip = _tooltipText ?? "";
 
                 if (!_iconAdded)
@@ -172,7 +165,19 @@ namespace Avalonia.Win32
                 _iconStale = false;
             }
         }
-        
+
+        private static Win32Icon GetOrCreateEmptyIcon()
+        {
+            if (s_emptyIcon is null)
+            {
+                using var bitmap = new WriteableBitmap(
+                    new PixelSize(32, 32), new Vector(96, 96), PixelFormats.Bgra8888, AlphaFormat.Unpremul);
+                s_emptyIcon = new Win32Icon(bitmap);
+            }
+
+            return s_emptyIcon;
+        }
+
         private double GetTaskBarMonScalingOrDefault()
         {
             if (ShCoreAvailable && Win32Platform.WindowsVersion > PlatformConstants.Windows8_1)