Fix: Fixed an issue when multiple threads handle CanWindowToFront flag

Author: Jack251970

src/Files.App/MainWindow.xaml.cs

@@ -20,6 +20,7 @@ public sealed partial class MainWindow : WinUIEx.WindowEx
 
 		public nint WindowHandle { get; }
 		private bool CanWindowToFront { get; set; } = true;
+		private readonly object _canWindowToFrontLock = new();
 
 		public MainWindow()
 		{
@@ -343,15 +344,18 @@ x.tabItem.NavigationParameter.NavigationParameter is PaneNavigationArguments pan
 			}
 		}
 
-		public bool SetCanWindowToFront(bool canWindowToFront)
-		{
-			if (CanWindowToFront != canWindowToFront)
-			{
-				CanWindowToFront = canWindowToFront;
-				return true;
-			}
-			return false;
-		}
+        public bool SetCanWindowToFront(bool canWindowToFront)
+        {
+            lock (_canWindowToFrontLock)
+            {
+                if (CanWindowToFront != canWindowToFront)
+                {
+                    CanWindowToFront = canWindowToFront;
+                    return true;
+                }
+                return false;
+            }
+        }
 
 		private const int WM_WINDOWPOSCHANGING = 0x0046;
 		private void WindowManager_WindowMessageReceived(object? sender, WinUIEx.Messaging.WindowMessageEventArgs e)