fix: 修复特殊情况下背景绘制不正确的问题

src/App/App.cpp

@@ -8,6 +8,7 @@
 
 
 using namespace winrt;
+using namespace Windows::Foundation;
 using namespace Windows::UI::Xaml;
 using namespace Windows::UI::Xaml::Media;
 
@@ -54,7 +55,25 @@ void App::OnClose() {
 bool App::Initialize(Magpie::Settings settings, uint64_t hwndHost) {
 	_settings = settings;
 	_hwndHost = hwndHost;
+	_isHostWndFocused = GetForegroundWindow() == (HWND)hwndHost;
 	return true;
 }
 
+event_token App::HostWndFocusChanged(EventHandler<bool> const& handler) {
+	return _hostWndFocusChangedEvent.add(handler);
+}
+
+void App::HostWndFocusChanged(event_token const& token) noexcept {
+	_hostWndFocusChangedEvent.remove(token);
+}
+
+void App::OnHostWndFocusChanged(bool isFocused) {
+	if (isFocused == _isHostWndFocused) {
+		return;
+	}
+
+	_isHostWndFocused = isFocused;
+	_hostWndFocusChangedEvent(*this, isFocused);
+}
+
 }

src/App/App.h

@@ -23,9 +23,20 @@ public:
 		return _settings;
 	}
 
+	event_token HostWndFocusChanged(Windows::Foundation::EventHandler<bool> const& handler);
+	void HostWndFocusChanged(event_token const& token) noexcept;
+
+	void OnHostWndFocusChanged(bool isFocused);
+	bool IsHostWndFocused() const noexcept {
+		return _isHostWndFocused;
+	}
+
 private:
-	Magpie::Settings _settings;
-	uint64_t _hwndHost;
+	Magpie::Settings _settings{ nullptr };
+	uint64_t _hwndHost{};
+
+	event<Windows::Foundation::EventHandler<bool>> _hostWndFocusChangedEvent;
+	bool _isHostWndFocused = false;
 };
 
 }

src/App/App.idl

@@ -21,5 +21,9 @@ namespace Magpie{
 
 		Settings Settings{ get; };
 		UInt64 HwndHost{ get; };
+
+		Boolean IsHostWndFocused { get; };
+		event Windows.Foundation.EventHandler<Boolean> HostWndFocusChanged;
+		void OnHostWndFocusChanged(Boolean isFocused);
 	}
 }

src/App/MainPage.cpp

@@ -33,12 +33,11 @@ MainPage::MainPage() {
 	_hwndHost = (HWND)Application::Current().as<App>().HwndHost();
 
 	_settings = Application::Current().as<Magpie::App>().Settings();
-	_micaBrush = Magpie::MicaBrush(*this);
 
 	_UpdateTheme();
 	_settings.ThemeChanged([this](const auto&, int) { _UpdateTheme(); });
 
-	Background(_micaBrush);
+	Background(Magpie::MicaBrush(*this));
 }
 
 MainPage::~MainPage() {
@@ -68,10 +67,6 @@ IInspectable MainPage::RootNavigationView() {
 	return __super::RootNavigationView();
 }
 
-void MainPage::OnHostFocusChanged(bool isFocused) {
-	_micaBrush.OnHostFocusChanged(isFocused);
-}
-
 void MainPage::_UpdateTheme() {
 	constexpr const DWORD DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1 = 19;
 	constexpr const DWORD DWMWA_MICA_EFFECT = 1029;

src/App/MainPage.h

@@ -18,8 +18,6 @@ namespace winrt::Magpie::implementation
 
 		Windows::Foundation::IInspectable RootNavigationView();
 
-		void OnHostFocusChanged(bool isFocused);
-
 	private:
 		void _UpdateTheme();
 
@@ -32,7 +30,6 @@ namespace winrt::Magpie::implementation
 
 		Windows::UI::ViewManagement::UISettings _uiSettings;
 		event_token _colorChangedToken{};
-		Magpie::MicaBrush _micaBrush{ nullptr };
 
 		Magpie::Settings _settings{ nullptr };
 		std::optional<bool> _isDarkTheme;

src/App/MainPage.idl

@@ -5,8 +5,6 @@ namespace Magpie
 	{
 		MainPage();
 
-		void OnHostFocusChanged(Boolean isFocused);
-
 		Object RootNavigationView { get; };
 	}
 }

src/App/MicaBrush.cpp

@@ -103,17 +103,14 @@ namespace winrt::Magpie::implementation {
 MicaBrush::MicaBrush(FrameworkElement root) {
 	_rootElement = root;
 
+	_app = Application::Current().as<App>();
+
 	_hasMica = ApiInformation::IsMethodPresent(
 		name_of<Compositor>(),
 		L"TryCreateBlurredWallpaperBackdropBrush"
 	);
 }
 
-void MicaBrush::OnHostFocusChanged(bool isFocused) {
-	_windowActivated = isFocused;
-	_UpdateBrush();
-}
-
 void MicaBrush::OnConnected() {
 	if (_settings == nullptr)
 		_settings = UISettings();
@@ -127,12 +124,15 @@ void MicaBrush::OnConnected() {
 	if (!_energySaver.has_value())
 		_energySaver = PowerManager::EnergySaverStatus() == EnergySaverStatus::On;
 
+	_windowActivated = _app.IsHostWndFocused();
+
 	_UpdateBrush();
 
 	_highContrastChangedToken = _accessibilitySettings.HighContrastChanged({ this, &MicaBrush::_AccessibilitySettings_HighContrastChanged });
 	_energySaverStatusChangedToken = PowerManager::EnergySaverStatusChanged({ this, &MicaBrush::_PowerManager_EnergySaverStatusChanged });
 	_compositionCapabilitiesChangedToken = CompositionCapabilities::GetForCurrentView().Changed({ this, &MicaBrush::_CompositionCapabilities_Changed });
 	_rootElementThemeChangedToken = _rootElement.ActualThemeChanged({ this, &MicaBrush::_RootElement_ActualThemeChanged });
+	_hostWndFocusedChangedToken = _app.HostWndFocusChanged({this, &MicaBrush::_App_HostWndFocusedChanged});
 }
 
 void MicaBrush::OnDisconnected() {
@@ -155,6 +155,9 @@ void MicaBrush::OnDisconnected() {
 	_rootElement.ActualThemeChanged(_rootElementThemeChangedToken);
 	_rootElementThemeChangedToken = {};
 
+	_app.HostWndFocusChanged(_hostWndFocusedChangedToken);
+	_hostWndFocusedChangedToken = {};
+
 	if (CompositionBrush() != nullptr) {
 		CompositionBrush().Close();
 		CompositionBrush(nullptr);
@@ -183,6 +186,11 @@ void MicaBrush::_RootElement_ActualThemeChanged(Windows::UI::Xaml::FrameworkElem
 	_UpdateBrush();
 }
 
+void MicaBrush::_App_HostWndFocusedChanged(IInspectable const&, bool isFocused) {
+	_windowActivated = isFocused;
+	_UpdateBrush();
+}
+
 void MicaBrush::_UpdateBrush() {
 	if (_settings == nullptr || _accessibilitySettings == nullptr) {
 		return;

src/App/MicaBrush.h

@@ -8,8 +8,6 @@ namespace winrt::Magpie::implementation {
 struct MicaBrush : MicaBrushT<MicaBrush> {
 	MicaBrush(Windows::UI::Xaml::FrameworkElement root);
 
-	void OnHostFocusChanged(bool isFocused);
-
 	void OnConnected();
 	void OnDisconnected();
 
@@ -32,6 +30,12 @@ private:
 		Windows::UI::Xaml::FrameworkElement const&,
 		Windows::Foundation::IInspectable const&
 	);
+	void _App_HostWndFocusedChanged(
+		Windows::Foundation::IInspectable const&,
+		bool isFocused
+	);
+
+	App _app{ nullptr };
 
 	Windows::UI::Xaml::FrameworkElement _rootElement{ nullptr };
 	bool _windowActivated = false;
@@ -46,6 +50,7 @@ private:
 	winrt::event_token _energySaverStatusChangedToken{};
 	winrt::event_token _compositionCapabilitiesChangedToken{};
 	winrt::event_token _rootElementThemeChangedToken{};
+	winrt::event_token _hostWndFocusedChangedToken{};
 };
 
 }

src/App/MicaBrush.idl

@@ -1,9 +1,8 @@
 namespace Magpie
 {
+	[default_interface]
 	runtimeclass MicaBrush : Windows.UI.Xaml.Media.XamlCompositionBrushBase
 	{
 		MicaBrush(Windows.UI.Xaml.FrameworkElement root);
-
-		void OnHostFocusChanged(Boolean isFocused);
 	}
 }

src/Magpie/XamlApp.cpp

@@ -20,6 +20,8 @@ using namespace Magpie;
 static constexpr const wchar_t* XAML_HOST_CLASS_NAME = L"Magpie_XamlHost";
 static constexpr const wchar_t* MUTEX_NAME = L"{4C416227-4A30-4A2F-8F23-8701544DD7D6}";
 
+static constexpr UINT CHECK_FORGROUND_TIMER_ID = 1;
+
 
 bool XamlApp::Initialize(HINSTANCE hInstance) {
 	_hMutex.reset(CreateMutex(nullptr, TRUE, MUTEX_NAME));
@@ -153,6 +155,19 @@ bool XamlApp::Initialize(HINSTANCE hInstance) {
 		}
 	});
 
+	{
+		// SetTimer 之前推荐先调用 SetUserObjectInformation
+		BOOL value = FALSE;
+		if (!SetUserObjectInformation(GetCurrentProcess(), UOI_TIMERPROC_EXCEPTION_SUPPRESSION, &value, sizeof(value))) {
+			Logger::Get().Win32Error("SetUserObjectInformation 失败");
+		}
+
+		// 监听 WM_ACTIVATE 不完全可靠，因此定期检查前台窗口以确保背景绘制正确
+		if (SetTimer(_hwndXamlHost, CHECK_FORGROUND_TIMER_ID, 250, nullptr) == 0) {
+			Logger::Get().Win32Error("SetTimer 失败");
+		}
+	}
+
 	return true;
 }
 
@@ -193,6 +208,14 @@ void XamlApp::_OnResize() {
 
 LRESULT XamlApp::_WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
 	switch (message) {
+	case WM_HOTKEY:
+	{
+		if (message >= 0) {
+			return 0;
+		}
+
+		break;
+	}
 	case WM_KEYDOWN:
 	{
 		if (wParam == VK_TAB) {
@@ -247,17 +270,31 @@ LRESULT XamlApp::_WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
 	case WM_ACTIVATE:
 	{
 		if (LOWORD(wParam) != WA_INACTIVE) {
-			_mainPage.OnHostFocusChanged(true);
+			_uwpApp.OnHostWndFocusChanged(true);
 			if (_hwndXamlIsland) {
 				SetFocus(_hwndXamlIsland);
 			}
 		} else {
-			_mainPage.OnHostFocusChanged(false);
+			_uwpApp.OnHostWndFocusChanged(false);
 			_CloseAllXamlPopups();
 		}
 		
 		return 0;
 	}
+	case WM_TIMER:
+	{
+		if (wParam == CHECK_FORGROUND_TIMER_ID) {
+			if (GetForegroundWindow() == _hwndXamlHost) {
+				_uwpApp.OnHostWndFocusChanged(true);
+			} else {
+				_uwpApp.OnHostWndFocusChanged(false);
+				_CloseAllXamlPopups();
+			}
+			return 0;
+		}
+
+		break;
+	}
 	case WM_MOVING:
 	{
 		_CloseAllXamlPopups();