Anwenden von Mica- oder Acrylmaterialien in Desktop-Apps für Windows 11

MicaController micaController;

bool TrySetMicaBackdrop(bool useMicaAlt)
{
    if (MicaController.IsSupported())
    {
        ...
        micaController = new MicaController();
        micaController.Kind = useMicaAlt ? MicaKind.BaseAlt : MicaKind.Base;
        ...
    }
}

// namespace MUCSB = Microsoft::UI::Composition::SystemBackdrops;

winrt::MUCSB::MicaController m_backdropController{ nullptr };

void SetBackground(bool useMicaAlt)
{
    if (winrt::MUCSB::MicaController::IsSupported())
    {
        ...
        m_backdropController = winrt::MUCSB::MicaController();
        m_backdropController.Kind(useMicaAlt 
            ? winrt::MUCSB::MicaKind::BaseAlt 
            : winrt::MUCSB::MicaKind::Base);
        ...
    }
}

DesktopAcrylicController acrylicController;

bool TrySetAcrylicBackdrop(bool useAcrylicThin)
{
    if (DesktopAcrylicController.IsSupported())
    {
        ...
        acrylicController = new DesktopAcrylicController();
        acrylicController.Kind = useAcrylicThin 
            ? DesktopAcrylicKind.Thin : DesktopAcrylicKind.Base;
        ...
    }
}

// namespace MUCSB = Microsoft::UI::Composition::SystemBackdrops;

winrt::MUCSB::DesktopAcrylicController m_backdropController{ nullptr };

void SetBackground(bool useAcrylicThin)
{
    if (winrt::MUCSB::DesktopAcrylicController::IsSupported())
    {
        ...
        m_backdropController = winrt::MUCSB::DesktopAcrylicController();
        m_backdropController.Kind(useAcrylicThin 
            ? winrt::MUCSB::DesktopAcrylicKind::Thin 
            : winrt::MUCSB::DesktopAcrylicKind::Base);
        ...
    }
}

using Microsoft.UI.Composition;
using Microsoft.UI.Composition.SystemBackdrops;
using Microsoft.UI.Xaml;
using WinRT; // required to support Window.As<ICompositionSupportsSystemBackdrop>()

public sealed partial class MainWindow : Window
{
    MicaController micaController;
    SystemBackdropConfiguration configurationSource;

    public MainWindow()
    {
        this.InitializeComponent();

        TrySetMicaBackdrop(false);
    }

    bool TrySetMicaBackdrop(bool useMicaAlt)
    {
        if (MicaController.IsSupported())
        {
            DispatcherQueue.EnsureSystemDispatcherQueue();

            // Hooking up the policy object.
            configurationSource = new SystemBackdropConfiguration();
            Activated += Window_Activated;
            Closed += Window_Closed;
            ((FrameworkElement)Content).ActualThemeChanged += Window_ThemeChanged;

            // Initial configuration state.
            configurationSource.IsInputActive = true;
            SetConfigurationSourceTheme();

            micaController = new MicaController
            {
                Kind = useMicaAlt ? MicaKind.BaseAlt : MicaKind.Base
            };

            // Enable the system backdrop.
            // Note: Be sure to have "using WinRT;" to support the Window.As<...>() call.
            micaController.AddSystemBackdropTarget(
                this.As<ICompositionSupportsSystemBackdrop>());
            micaController.SetSystemBackdropConfiguration(configurationSource);
            return true; // Succeeded.
        }

        return false; // Mica is not supported on this system.
    }

    private void Window_Activated(object sender, WindowActivatedEventArgs args)
    {
        if (configurationSource != null)
            configurationSource.IsInputActive = 
                args.WindowActivationState != WindowActivationState.Deactivated;
    }

    private void Window_Closed(object sender, WindowEventArgs args)
    {
        // Make sure any Mica/Acrylic controller is disposed
        // so it doesn't try to use this closed window.
        micaController?.Dispose();
        micaController = null;
        Activated -= Window_Activated;
        configurationSource = null;
    }

    private void Window_ThemeChanged(FrameworkElement sender, object args)
    {
        if (configurationSource != null)
            SetConfigurationSourceTheme();
    }

    private void SetConfigurationSourceTheme()
    {
        if (configurationSource != null)
            configurationSource.Theme = 
                (SystemBackdropTheme)((FrameworkElement)Content).ActualTheme;
    }
}

// pch.h
...
#include <winrt/Microsoft.UI.Composition.SystemBackdrops.h>
#include <winrt/Windows.System.h>
#include <dispatcherqueue.h>

// MainWindow.xaml.h
...
namespace winrt
{
    namespace MUC = Microsoft::UI::Composition;
    namespace MUCSB = Microsoft::UI::Composition::SystemBackdrops;
    namespace MUX = Microsoft::UI::Xaml;
    namespace WS = Windows::System;
}
...
struct MainWindow : MainWindowT<MainWindow>
{
    winrt::MUCSB::SystemBackdropConfiguration m_configuration{ nullptr };
    winrt::MUCSB::MicaController m_backdropController{ nullptr };
    winrt::MUX::Window::Activated_revoker m_activatedRevoker;
    winrt::MUX::Window::Closed_revoker m_closedRevoker;
    winrt::MUX::FrameworkElement::ActualThemeChanged_revoker m_themeChangedRevoker;
    winrt::MUX::FrameworkElement m_rootElement{ nullptr };
    winrt::WS::DispatcherQueueController m_dispatcherQueueController{ nullptr };

    MainWindow::MainWindow()
    {
        InitializeComponent();

        SetBackground();

        m_closedRevoker = this->Closed(winrt::auto_revoke, [&](auto&&, auto&&)
        {
            if (nullptr != m_backdropController)
            {
                m_backdropController.Close();
                m_backdropController = nullptr;
            }

            if (nullptr != m_dispatcherQueueController)
            {
                m_dispatcherQueueController.ShutdownQueueAsync();
                m_dispatcherQueueController = nullptr;
            }
        });
    }

    void SetBackground()
    {
        if (winrt::MUCSB::MicaController::IsSupported())
        {
            // We ensure that there is a Windows.System.DispatcherQueue on the current thread.
            // Always check if one already exists before attempting to create a new one.
            if (nullptr == winrt::WS::DispatcherQueue::GetForCurrentThread() &&
                nullptr == m_dispatcherQueueController)
            {
                m_dispatcherQueueController = CreateSystemDispatcherQueueController();
            }

            // Setup the SystemBackdropConfiguration object.
            SetupSystemBackdropConfiguration();

            // Setup Mica on the current Window.
            m_backdropController = winrt::MUCSB::MicaController();
            m_backdropController.SetSystemBackdropConfiguration(m_configuration);
            m_backdropController.AddSystemBackdropTarget(
                this->m_inner.as<winrt::MUC::ICompositionSupportsSystemBackdrop>());
        }
    }

    winrt::WS::DispatcherQueueController CreateSystemDispatcherQueueController()
    {
        DispatcherQueueOptions options
        {
            sizeof(DispatcherQueueOptions),
            DQTYPE_THREAD_CURRENT,
            DQTAT_COM_NONE
        };

        ::ABI::Windows::System::IDispatcherQueueController* ptr{ nullptr };
        winrt::check_hresult(CreateDispatcherQueueController(options, &ptr));
        return { ptr, take_ownership_from_abi };
    }

    void SetupSystemBackdropConfiguration()
    {
        m_configuration = winrt::MUCSB::SystemBackdropConfiguration();

        // Activation state.
        m_activatedRevoker = this->Activated(winrt::auto_revoke,
            [&](auto&&, MUX::WindowActivatedEventArgs const& args)
            {
                m_configuration.IsInputActive(
                    winrt::MUX::WindowActivationState::Deactivated != args.WindowActivationState());
            });

        // Initial state.
        m_configuration.IsInputActive(true);

        // Application theme.
        m_rootElement = this->Content().try_as<winrt::MUX::FrameworkElement>();
        if (nullptr != m_rootElement)
        {
            m_themeChangedRevoker = m_rootElement.ActualThemeChanged(winrt::auto_revoke,
                [&](auto&&, auto&&)
                {
                    m_configuration.Theme(
                        ConvertToSystemBackdropTheme(m_rootElement.ActualTheme()));
                });

            // Initial state.
            m_configuration.Theme(
                ConvertToSystemBackdropTheme(m_rootElement.ActualTheme()));
        }
    }

    winrt::MUCSB::SystemBackdropTheme ConvertToSystemBackdropTheme(
        winrt::MUX::ElementTheme const& theme)
    {
        switch (theme)
        {
        case winrt::MUX::ElementTheme::Dark:
            return winrt::MUCSB::SystemBackdropTheme::Dark;
        case winrt::MUX::ElementTheme::Light:
            return winrt::MUCSB::SystemBackdropTheme::Light;
        default:
            return winrt::MUCSB::SystemBackdropTheme::Default;
        }
    }
    ...
};
...