/// <summary>
/// Captures a screenshot of a window using Windows GDI. Captures transparency.
/// </summary>
/// <param name="handle">handle of the window to capture</param>
/// <returns>the captured window image</returns>
private static Image CaptureWindowWithTransparencyGDI(IntPtr handle, Rectangle windowRect)
{
Image windowImage = null;
Bitmap whiteBGImage = null, blackBGImage = null, white2BGImage = null;
try
{
using (new Freeze(handle))
using (Form form = new Form())
{
form.BackColor = Color.White;
form.FormBorderStyle = FormBorderStyle.None;
form.ShowInTaskbar = false;
int offset = Engine.conf.ActiveWindowIncludeShadows && !NativeMethods.IsWindowMaximized(handle) ? 20 : 0;
windowRect = windowRect.AddMargin(offset);
windowRect.Intersect(GraphicsMgr.GetScreenBounds());
NativeMethods.ShowWindow(form.Handle, (int)NativeMethods.WindowShowStyle.ShowNormalNoActivate);
NativeMethods.SetWindowPos(form.Handle, handle, windowRect.X, windowRect.Y, windowRect.Width, windowRect.Height, NativeMethods.SWP_NOACTIVATE);
Application.DoEvents();
whiteBGImage = (Bitmap)CaptureRectangle(NativeMethods.GetDesktopWindow(), windowRect);
form.BackColor = Color.Black;
Application.DoEvents();
blackBGImage = (Bitmap)CaptureRectangle(NativeMethods.GetDesktopWindow(), windowRect);
if (!Engine.conf.ActiveWindowGDIFreezeWindow)
{
form.BackColor = Color.White;
Application.DoEvents();
white2BGImage = (Bitmap)CaptureRectangle(NativeMethods.GetDesktopWindow(), windowRect);
}
}
if (Engine.conf.ActiveWindowGDIFreezeWindow || whiteBGImage.AreBitmapsEqual(white2BGImage))
{
windowImage = GraphicsMgr.ComputeOriginal(whiteBGImage, blackBGImage);
}
else
{
windowImage = (Image)whiteBGImage.Clone();
}
}
finally
{
if (whiteBGImage != null) whiteBGImage.Dispose();
if (blackBGImage != null) blackBGImage.Dispose();
if (white2BGImage != null) white2BGImage.Dispose();
}
if (windowImage != null)
{
Rectangle windowRectCropped = GraphicsMgr.GetCroppedArea((Bitmap)windowImage);
windowImage = GraphicsMgr.CropImage(windowImage, windowRectCropped);
if (Engine.conf.ShowCursor)
{
windowRect.X += windowRectCropped.X;
windowRect.Y += windowRectCropped.Y;
DrawCursor(windowImage, windowRect.Location);
}
if (Engine.conf.ActiveWindowShowCheckers)
{
windowImage = ImageEffects.DrawCheckers(windowImage);
}
}
return windowImage;
}
