Windows 10 Creaters Update 画中画模式和窗口高斯模糊

在Windows 10 Creaters Update中，可以给窗口设置高斯模糊了，只要几行代码！

    <Grid   Loaded="Grid_Loaded">
        <Grid x:Name="mg"></Grid>
        <Grid Background="Blue" Opacity="0.4" x:Name="rootGrid" ></Grid>
        <!--your uielements-->
    </Grid>

        Windows.UI.Composition.Compositor _compositor;
        Windows.UI.Composition.SpriteVisual _hostSprite;
        public MainPage()
        {
            this.InitializeComponent();
            _compositor = Windows.UI.Xaml.Hosting.ElementCompositionPreview.GetElementVisual(this).Compositor;
        }

        private void Grid_Loaded(object sender, RoutedEventArgs e)
        {
            _hostSprite = _compositor.CreateSpriteVisual();
            _hostSprite.Size = new System.Numerics.Vector2((float)rootGrid.ActualWidth, (float)rootGrid.ActualHeight);

            ElementCompositionPreview.SetElementChildVisual(mg, _hostSprite);
            _hostSprite.Brush = _compositor.CreateHostBackdropBrush();
        }

效果

XAML里的那个Grid的颜色是可以换的，删了也行。那个是为了实现向开始菜单那样特定颜色的模糊。

不过这个方法在新增加的画中画模式无效

关于如何实现画中画其实很简单

检测是否支持画中画

ApplicationView.GetForCurrentView().IsViewModeSupported(ApplicationViewMode.CompactOverlay)

进入画中画

bool modeSwitched = await ApplicationView.GetForCurrentView().TryEnterViewModeAsync(ApplicationViewMode.CompactOverlay);

    ViewModePreferences compactOptions = ViewModePreferences.CreateDefault(ApplicationViewMode.CompactOverlay);
    compactOptions.CustomSize = , );//你要的窗口大小
    bool modeSwitched = await ApplicationView.GetForCurrentView().TryEnterViewModeAsync(ApplicationViewMode.Default, compactOptions);

退出画中画

bool modeSwitched = await ApplicationView.GetForCurrentView().TryEnterViewModeAsync(ApplicationViewMode.Default);

也可以结合UWP的多窗口功能

await CoreApplication.CreateNewView().Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        var frame = new Frame();
        compactViewId = ApplicationView.GetForCurrentView().Id;
        frame.Navigate(typeof(SecondaryCompactViewPage));
        Window.Current.Content = frame;
        Window.Current.Activate();
        ApplicationView.GetForCurrentView().Title = "画中画窗口";
    });
    bool viewShown = await ApplicationViewSwitcher.TryShowAsViewModeAsync(compactViewId, ApplicationViewMode.CompactOverlay);

微软的多窗口示例：https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/MultipleViews

微软关于画中画功能的介绍：https://blogs.msdn.microsoft.com/universal-windows-app-model/2017/02/11/compactoverlay-mode-aka-picture-in-picture/