public static Image CaptureWindowTransparent(IntPtr handle)
{
if (handle.ToInt32() > 0)
{
Rectangle rect = CaptureHelpers.GetWindowRectangle(handle);
if (CaptureShadow && !NativeMethods.IsZoomed(handle) && NativeMethods.IsDWMEnabled())
{
rect.Inflate(ShadowOffset, ShadowOffset);
rect.Intersect(CaptureHelpers.GetScreenBounds());
}
Bitmap whiteBackground = null, blackBackground = null, whiteBackground2 = null;
CursorData cursor = null;
bool isTransparent = false, isTaskbarHide = false;
try
{
if (AutoHideTaskbar)
{
isTaskbarHide = NativeMethods.SetTaskbarVisibilityIfIntersect(false, rect);
}
if (CaptureCursor)
{
try
{
cursor = new CursorData();
}
catch (Exception e)
{
DebugHelper.WriteException(e, "Cursor capture failed.");
}
}
using (Form form = new Form())
{
form.BackColor = Color.White;
form.FormBorderStyle = FormBorderStyle.None;
form.ShowInTaskbar = false;
form.StartPosition = FormStartPosition.Manual;
form.Location = new Point(rect.X, rect.Y);
form.Size = new Size(rect.Width, rect.Height);
NativeMethods.ShowWindow(form.Handle, (int)WindowShowStyle.ShowNoActivate);
if (!NativeMethods.SetWindowPos(form.Handle, handle, 0, 0, 0, 0,
SetWindowPosFlags.SWP_NOMOVE | SetWindowPosFlags.SWP_NOSIZE | SetWindowPosFlags.SWP_NOACTIVATE))
{
form.Close();
DebugHelper.WriteLine("Transparent capture failed. Reason: SetWindowPos fail.");
return CaptureWindow(handle);
}
Thread.Sleep(10);
Application.DoEvents();
whiteBackground = (Bitmap)CaptureRectangleNative(rect);
form.BackColor = Color.Black;
Application.DoEvents();
blackBackground = (Bitmap)CaptureRectangleNative(rect);
form.BackColor = Color.White;
Application.DoEvents();
whiteBackground2 = (Bitmap)CaptureRectangleNative(rect);
form.Close();
}
Bitmap transparentImage;
if (ImageHelpers.IsImagesEqual(whiteBackground, whiteBackground2))
{
transparentImage = CreateTransparentImage(whiteBackground, blackBackground);
isTransparent = true;
}
else
{
DebugHelper.WriteLine("Transparent capture failed. Reason: Images not equal.");
transparentImage = whiteBackground2;
}
if (cursor != null && cursor.IsVisible)
{
Point cursorOffset = CaptureHelpers.ScreenToClient(rect.Location);
cursor.DrawCursorToImage(transparentImage, cursorOffset);
}
if (isTransparent)
{
transparentImage = TrimTransparent(transparentImage);
if (!CaptureShadow)
{
TrimShadow(transparentImage);
}
}
return transparentImage;
}
finally
{
if (isTaskbarHide)
{
NativeMethods.SetTaskbarVisibility(true);
}
if (whiteBackground != null) whiteBackground.Dispose();
if (blackBackground != null) blackBackground.Dispose();
if (isTransparent && whiteBackground2 != null) whiteBackground2.Dispose();
if (cursor != null) cursor.Dispose();
}
}
return null;
}
private Image CaptureRectangleNative(IntPtr handle, Rectangle rect, bool captureCursor = false)
{
if (rect.Width == 0 || rect.Height == 0)
{
return null;
}
IntPtr hdcSrc = NativeMethods.GetWindowDC(handle);
IntPtr hdcDest = NativeMethods.CreateCompatibleDC(hdcSrc);
IntPtr hBitmap = NativeMethods.CreateCompatibleBitmap(hdcSrc, rect.Width, rect.Height);
IntPtr hOld = NativeMethods.SelectObject(hdcDest, hBitmap);
NativeMethods.BitBlt(hdcDest, 0, 0, rect.Width, rect.Height, hdcSrc, rect.X, rect.Y, CopyPixelOperation.SourceCopy | CopyPixelOperation.CaptureBlt);
if (captureCursor)
{
Point cursorOffset = CaptureHelpers.ScreenToClient(rect.Location);
try
{
using (CursorData cursorData = new CursorData())
{
cursorData.DrawCursorToHandle(hdcDest, cursorOffset);
}
}
catch (Exception e)
{
DebugHelper.WriteException(e, "Cursor capture failed.");
}
}
NativeMethods.SelectObject(hdcDest, hOld);
NativeMethods.DeleteDC(hdcDest);
NativeMethods.ReleaseDC(handle, hdcSrc);
Image img = Image.FromHbitmap(hBitmap);
NativeMethods.DeleteObject(hBitmap);
return img;
}
