private void UpdateBlur(Visual backgroundVisual)
{
if (!BlurEnabled)
{
return;
}
var backgroundRenderTarget = new RenderTargetBitmap((int)ItemPanel.RenderSize.Width, (int)ItemPanel.RenderSize.Height, 96, 96, PixelFormats.Pbgra32);
backgroundRenderTarget.Render(backgroundVisual);
backgroundRenderTarget.Freeze();
var itemPanelLocation = ItemPanel.PointToScreen(new Point(0, 0));
var offset = PointFromScreen(itemPanelLocation);
var blurRegion = BuildRegionFromBitmap(backgroundRenderTarget, offset);
var handle = new WindowInteropHelper(this).Handle;
var blurBehind = new Api.DWM_BLURBEHIND
{
fEnable = true,
fTransitionOnMaximized = true,
dwFlags = Api.DWM_BB.BlurRegion | Api.DWM_BB.Enable | Api.DWM_BB.TransitionMaximized,
hRgnBlur = blurRegion.GetHrgn(System.Drawing.Graphics.FromHwnd(handle))
};
Api.DwmEnableBlurBehindWindow(handle, ref blurBehind);
}