using System;

using System.IO;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Navigation;

using System.Windows.Interop;

using System.Runtime.InteropServices;

using System.Collections.Generic;

namespace AeroGlassExample

{

    public class GlassHelper

    {

        struct MARGINS

        {

            public MARGINS(Thickness t)

            {

                Left = (int)t.Left;

                Right = (int)t.Right;

                Top = (int)t.Top;

                Bottom = (int)t.Bottom;

            }

            public int Left;

            public int Right;

            public int Top;

            public int Bottom;

        }

        [DllImport("dwmapi.dll", PreserveSig = false)]

        static extern void DwmExtendFrameIntoClientArea(IntPtr hwnd, ref MARGINS margins);

        [DllImport("dwmapi.dll", PreserveSig = false)]

        static extern bool DwmIsCompositionEnabled();

        public static bool ExtendGlassFrame(Window window, Thickness margin)

        {

            if (!DwmIsCompositionEnabled())

                return false;

            IntPtr hwnd = new WindowInteropHelper(window).Handle;

            if (hwnd == IntPtr.Zero)

                throw new InvalidOperationException("The Window must be shown before extending glass.");

            // Set the background to transparent from both the WPF and Win32 perspectives

            SolidColorBrush background = new SolidColorBrush(Colors.Red);

            background.Opacity = 0.5;

            window.Background = Brushes.Transparent;

            HwndSource.FromHwnd(hwnd).CompositionTarget.BackgroundColor = Colors.Transparent;

            MARGINS margins = new MARGINS(margin);

            DwmExtendFrameIntoClientArea(hwnd, ref margins);

            return true;

        }

    }

} 

using System;

using System.Text;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Shapes;

namespace AeroGlassExample

{

    /// <summary>

    /// Interaction logic for Window1.xaml

    /// </summary>

    public partial class Window1 : System.Windows.Window

    {

        private bool neverRendered = true;

        public Window1()

        {

            InitializeComponent();

            this.SourceInitialized += new EventHandler(Window1_SourceInitialized);

        }

        void Window1_SourceInitialized(object sender, EventArgs e)

        {

            GlassHelper.ExtendGlassFrame(this, new Thickness(-1));

        }

        protected override void OnContentRendered(EventArgs e)

        {

            if (this.neverRendered)

            {

                // The window takes the size of its content because SizeToContent

                // is set to WidthAndHeight in the markup. We then allow

                // it to be set by the user, and have the content take the size

                // of the window.

                this.SizeToContent = SizeToContent.Manual;

                FrameworkElement root = this.Content as FrameworkElement;

                if (root != null)

                {

                    root.Width = double.NaN;

                    root.Height = double.NaN;

                }

                this.neverRendered = false;

            }

            base.OnContentRendered(e);

        }

    }

}