Fix: Fixed the taskbar behavior in full screen mode (#14300)

Author: el-ev

src/Files.App/Helpers/Application/AppLifecycleHelper.cs

@@ -320,5 +320,21 @@ public static void HandleAppUnhandledException(Exception? ex, bool showToastNoti
 			}
 			Process.GetCurrentProcess().Kill();
 		}
+
+		/// <summary>
+		///	Checks if the taskbar is set to auto-hide.
+		/// </summary>
+		public static bool IsAutoHideTaskbarEnabled()
+		{
+			const string registryKey = @"Software\Microsoft\Windows\CurrentVersion\Explorer\StuckRects3";
+			const string valueName = "Settings";
+
+			using var key = Microsoft.Win32.Registry.CurrentUser.OpenSubKey(registryKey);
+
+			var value = key?.GetValue(valueName) as byte[];
+
+			// The least significant bit of the 9th byte controls the auto-hide setting																		
+			return value != null && ((value[8] & 0x01) == 1);
+		}
 	}
 }

src/Files.App/MainWindow.xaml.cs

@@ -56,7 +56,11 @@ private void EnsureEarlyWindow()
 
 			// Workaround for full screen window messing up the taskbar
 			// https://github.com/microsoft/microsoft-ui-xaml/issues/8431
-			InteropHelpers.SetPropW(WindowHandle, "NonRudeHWND", new IntPtr(1));
+			// This property should only be set if the "Automatically hide the taskbar" in Windows 11,
+			// or "Automatically hide the taskbar in desktop mode" in Windows 10 is enabled.
+			// Setting this property when the setting is disabled will result in the taskbar overlapping the application
+			if (AppLifecycleHelper.IsAutoHideTaskbarEnabled()) 
+				InteropHelpers.SetPropW(WindowHandle, "NonRudeHWND", new IntPtr(1));
 		}
 
 		public void ShowSplashScreen()