protected override void OnPaint(bool isPopup, Structs.Rect dirtyRect, IntPtr buffer, int width, int height)
{
if (isTakingScreenshot)
{
//We ignore the first n number of frames
if (ignoreFrames > 0)
{
ignoreFrames--;
return;
}
//Wait until we have a frame that matches the updated size we requested
if (screenshotSize.HasValue && screenshotSize.Value.Width == width && screenshotSize.Value.Height == height)
{
var stride = width * BytesPerPixel;
var numberOfBytes = stride * height;
//Create out own memory mapped view for the screenshot and copy the buffer into it.
//If we were going to create a lot of screenshots then it would be better to allocate a large buffer
//and reuse it.
var mappedFile = MemoryMappedFile.CreateNew(null, numberOfBytes, MemoryMappedFileAccess.ReadWrite);
var viewAccessor = mappedFile.CreateViewAccessor();
CopyMemory(viewAccessor.SafeMemoryMappedViewHandle.DangerousGetHandle(), buffer, (uint)numberOfBytes);
//Bitmaps need to be created on the UI thread
Dispatcher.BeginInvoke((Action)(() =>
{
var backBuffer = mappedFile.SafeMemoryMappedFileHandle.DangerousGetHandle();
//NOTE: Interopbitmap is not capable of supporting DPI scaling
var bitmap = (InteropBitmap)Imaging.CreateBitmapSourceFromMemorySection(backBuffer,
width, height, PixelFormats.Bgra32, stride, 0);
//Using TaskExtensions.TrySetResultAsync extension method so continuation runs on Threadpool
screenshotTaskCompletionSource.TrySetResultAsync(bitmap);
isTakingScreenshot = false;
var browserHost = GetBrowser().GetHost();
//Return the framerate to the previous value
browserHost.WindowlessFrameRate = oldFrameRate;
//Let the browser know the size changes so normal rendering can continue
browserHost.WasResized();
if (viewAccessor != null)
{
viewAccessor.Dispose();
}
if (mappedFile != null)
{
mappedFile.Dispose();
}
}));
}
}
else
{
base.OnPaint(isPopup, dirtyRect, buffer, width, height);
}
}
internal static extern bool GetWindowRect(IntPtr hWnd, out Rect lpRect);
public static extern bool GetWindowRect(IntPtr hWnd, out Structs.Rect RECT);
public static extern bool GetWindowRect(IntPtr hwnd, out Structs.Rect lpRect);
public static extern bool GetClientRect(IntPtr hWnd, out Structs.Rect RECT);