Fix: Fixed issue where window wasn't always brought to foreground (#14917)

Author: 0x5bfa

src/Files.App/Helpers/Interop/InteropHelpers.cs

@@ -29,9 +29,6 @@ public static class InteropHelpers
 		[DllImport("kernel32.dll")]
 		public static extern bool SetEvent(IntPtr hEvent);
 
-		[DllImport("user32.dll", SetLastError = true)]
-		public static extern void SwitchToThisWindow(IntPtr hWnd, bool altTab);
-
 		[DllImport("User32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
 		public static extern int GetDpiForWindow(IntPtr hwnd);
 

src/Files.App/Helpers/Win32/Win32Helper.WindowManagement.cs

@@ -0,0 +1,38 @@
+// Copyright (c) 2023 Files Community
+// Licensed under the MIT License. See the LICENSE.
+
+using Windows.Win32;
+using Windows.Win32.UI.WindowsAndMessaging;
+
+namespace Files.App.Helpers
+{
+	public static partial class Win32Helper
+	{
+		/// <summary>
+		/// Brings the app window to foreground.
+		/// </summary>
+		/// <remarks>
+		/// For more information, visit
+		/// <br/>
+		/// - <a href="https://stackoverflow.com/questions/1544179/what-are-the-differences-between-bringwindowtotop-setforegroundwindow-setwindo" />
+		/// <br/>
+		/// - <a href="https://stackoverflow.com/questions/916259/win32-bring-a-window-to-top" />
+		/// </remarks>
+		/// <param name="hWnd">The window handle to bring.</param>
+		public static unsafe void BringToForegroundEx(Windows.Win32.Foundation.HWND hWnd)
+		{
+			var hCurWnd = PInvoke.GetForegroundWindow();
+			var dwMyID = PInvoke.GetCurrentThreadId();
+			var dwCurID = PInvoke.GetWindowThreadProcessId(hCurWnd);
+
+			PInvoke.AttachThreadInput(dwCurID, dwMyID, true);
+
+			PInvoke.SetWindowPos(hWnd, (Windows.Win32.Foundation.HWND)(-1), 0, 0, 0, 0, SET_WINDOW_POS_FLAGS.SWP_NOSIZE | SET_WINDOW_POS_FLAGS.SWP_NOMOVE);
+			PInvoke.SetWindowPos(hWnd, (Windows.Win32.Foundation.HWND)(-2), 0, 0, 0, 0, SET_WINDOW_POS_FLAGS.SWP_SHOWWINDOW | SET_WINDOW_POS_FLAGS.SWP_NOSIZE | SET_WINDOW_POS_FLAGS.SWP_NOMOVE);
+			PInvoke.SetForegroundWindow(hWnd);
+			PInvoke.SetFocus(hWnd);
+			PInvoke.SetActiveWindow(hWnd);
+			PInvoke.AttachThreadInput(dwCurID, dwMyID, false);
+		}
+	}
+}

src/Files.App/MainWindow.xaml.cs

@@ -93,7 +93,9 @@ public async Task InitializeApplicationAsync(object activatedEventArgs)
 					}
 					else if (!(string.IsNullOrEmpty(launchArgs.Arguments) && MainPageViewModel.AppInstances.Count > 0))
 					{
-						InteropHelpers.SwitchToThisWindow(WindowHandle, true);
+						// Bring to foreground (#14730)
+						Win32Helper.BringToForegroundEx(new(WindowHandle));
+
 						await NavigationHelpers.AddNewTabByPathAsync(typeof(PaneHolderPage), launchArgs.Arguments, true);
 					}
 					else
@@ -106,6 +108,12 @@ public async Task InitializeApplicationAsync(object activatedEventArgs)
 					if (eventArgs.Uri.AbsoluteUri == "files-uwp:")
 					{
 						rootFrame.Navigate(typeof(MainPage), null, new SuppressNavigationTransitionInfo());
+
+						if (MainPageViewModel.AppInstances.Count > 0)
+						{
+							// Bring to foreground (#14730)
+							Win32Helper.BringToForegroundEx(new(WindowHandle));
+						}
 					}
 					else
 					{
@@ -171,7 +179,11 @@ public async Task InitializeApplicationAsync(object activatedEventArgs)
 						index = 1;
 					}
 					else
-						InteropHelpers.SwitchToThisWindow(WindowHandle, true);
+					{
+						// Bring to foreground (#14730)
+						Win32Helper.BringToForegroundEx(new(WindowHandle));
+					}
+
 					for (; index < fileArgs.Files.Count; index++)
 					{
 						await NavigationHelpers.AddNewTabByPathAsync(typeof(PaneHolderPage), fileArgs.Files[index].Path, true);
@@ -245,7 +257,9 @@ async Task PerformNavigationAsync(string payload, string selectItem = null)
 
 				if (rootFrame.Content is MainPage && MainPageViewModel.AppInstances.Any())
 				{
-					InteropHelpers.SwitchToThisWindow(WindowHandle, true);
+					// Bring to foreground (#14730)
+					Win32Helper.BringToForegroundEx(new(WindowHandle));
+
 					await NavigationHelpers.AddNewTabByParamAsync(typeof(PaneHolderPage), paneNavigationArgs);
 				}
 				else

src/Files.App/NativeMethods.txt

@@ -31,3 +31,11 @@ LPARAM
 WM_LBUTTONUP
 WM_RBUTTONUP
 WM_DESTROY
+SetForegroundWindow
+GetForegroundWindow
+GetCurrentThreadId
+GetWindowThreadProcessId
+AttachThreadInput
+SetWindowPos
+SetFocus
+SetActiveWindow