Aero ブラーを使用する場合は、 DwmEnableBlurBehindWindow APIを使用できます。これを利用した派生ウィンドウの例を次に示します。
public class BlurWindow : Window
{
#region Constants
private const int WM_DWMCOMPOSITIONCHANGED = 0x031E;
private const int DWM_BB_ENABLE = 0x1;
#endregion //Constants
#region Structures
[StructLayout( LayoutKind.Sequential )]
private struct DWM_BLURBEHIND
{
public int dwFlags;
public bool fEnable;
public IntPtr hRgnBlur;
public bool fTransitionOnMaximized;
}
[StructLayout( LayoutKind.Sequential )]
private struct MARGINS
{
public int cxLeftWidth;
public int cxRightWidth;
public int cyTopHeight;
public int cyBottomHeight;
}
#endregion //Structures
#region APIs
[DllImport( "dwmapi.dll", PreserveSig = false )]
private static extern void DwmEnableBlurBehindWindow(IntPtr hwnd, ref DWM_BLURBEHIND blurBehind);
[DllImport( "dwmapi.dll" )]
private static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMargins);
[DllImport( "dwmapi.dll", PreserveSig = false )]
private static extern bool DwmIsCompositionEnabled();
#endregion //APIs
#region Constructor
public BlurWindow()
{
this.WindowStyle = System.Windows.WindowStyle.None;
this.ResizeMode = System.Windows.ResizeMode.NoResize;
this.Background = Brushes.Transparent;
}
#endregion //Constructor
#region Base class overrides
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized( e );
if ( Environment.OSVersion.Version.Major >= 6 )
{
var hwnd = new WindowInteropHelper( this ).Handle;
var hs = HwndSource.FromHwnd( hwnd );
hs.CompositionTarget.BackgroundColor = Colors.Transparent;
hs.AddHook( new HwndSourceHook( this.WndProc ) );
this.InitializeGlass( hwnd );
}
}
#endregion //Base class overrides
#region Methods
#region InitializeGlass
private void InitializeGlass(IntPtr hwnd)
{
if ( !DwmIsCompositionEnabled() )
return;
// fill the background with glass
var margins = new MARGINS();
margins.cxLeftWidth = margins.cxRightWidth = margins.cyBottomHeight = margins.cyTopHeight = -1;
DwmExtendFrameIntoClientArea( hwnd, ref margins );
// initialize blur for the window
DWM_BLURBEHIND bbh = new DWM_BLURBEHIND();
bbh.fEnable = true;
bbh.dwFlags = DWM_BB_ENABLE;
DwmEnableBlurBehindWindow( hwnd, ref bbh );
}
#endregion //InitializeGlass
#region WndProc
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if ( msg == WM_DWMCOMPOSITIONCHANGED )
{
this.InitializeGlass( hwnd );
handled = false;
}
return IntPtr.Zero;
}
#endregion //WndProc
#endregion //Methods
}
BlurWindow の使用例を次に示します。
var w = new BlurWindow();
w.Width = 100;
w.Height = 100;
w.MouseLeftButtonDown += (s1, e1) => {
((Window)s1).DragMove();
e1.Handled = true;
};
w.Background = new SolidColorBrush( Color.FromArgb( 75, 255, 0, 0 ) );
w.Show();