public void UpdateResolution(SizeInt32 size)
{
if (size.Height <= 0 || size.Width <= 0)
{
return;
}
if (_framePool is not null && _session is not null)
{
// Unsubscribe from old framePool
_framePool.FrameArrived -= OnFrameArrived;
// Dispose old session and framePool
_session.Dispose();
_framePool.Dispose();
}
_canvasDevice = CanvasDevice.GetSharedDevice();
// Create a frame pool with room for only 1 frame because we're getting a single frame, not a video.
_framePool =
Direct3D11CaptureFramePool.Create(_canvasDevice, DirectXPixelFormat.B8G8R8A8UIntNormalized, 1, size);
_session = _framePool.CreateCaptureSession(GraphicsCaptureItem.CreateFromVisual(_capturedVisual));
_framePool.FrameArrived += OnFrameArrived;
_session.StartCapture();
}
//
// Renders a the given <see cref="Visual"/> to a <see cref="CanvasBitmap"/>. If <paramref name="size"/> is not
// specified, uses the size of <paramref name="visual"/>.
//
static async Task <CanvasBitmap> RenderVisualToBitmapAsync(Visual visual, SizeInt32?size = null)
{
// Get an object that enables capture from a visual.
var graphicsItem = GraphicsCaptureItem.CreateFromVisual(visual);
var canvasDevice = CanvasDevice.GetSharedDevice();
var tcs = new TaskCompletionSource <CanvasBitmap>();
// Create a frame pool with room for only 1 frame because we're getting a single frame, not a video.
const int numberOfBuffers = 1;
using (var framePool = Direct3D11CaptureFramePool.Create(
canvasDevice,
DirectXPixelFormat.B8G8R8A8UIntNormalized,
numberOfBuffers,
size ?? graphicsItem.Size))
{
void OnFrameArrived(Direct3D11CaptureFramePool sender, object args)
{
using (var frame = sender.TryGetNextFrame())
{
tcs.SetResult(frame != null
? CanvasBitmap.CreateFromDirect3D11Surface(canvasDevice, frame.Surface)
: null);
}
}
using (var session = framePool.CreateCaptureSession(graphicsItem))
{
framePool.FrameArrived += OnFrameArrived;
// Start capturing. The FrameArrived event will occur shortly.
session.StartCapture();
// Wait for the frame to arrive.
var result = await tcs.Task;
// !!!!!!!! NOTE !!!!!!!!
// This thread is now running inside the OnFrameArrived callback method.
// Unsubscribe now that we have captured the frame.
framePool.FrameArrived -= OnFrameArrived;
// Yield to allow the OnFrameArrived callback to unwind so that it is safe to
// Dispose the session and framepool.
await Task.Yield();
}
}
return(await tcs.Task);
}
private void MainWebView_Loaded(object sender, RoutedEventArgs e)
{
var compositor = Window.Current.Compositor;
var visual = ElementCompositionPreview.GetElementVisual(MainWebView);
var size = new SizeInt32()
{
Width = (int)MainWebView.ActualWidth,
Height = (int)MainWebView.ActualHeight
};
var item = GraphicsCaptureItem.CreateFromVisual(visual);
_capture = new SimpleCapture(_device, item, size);
var surface = _capture.CreateSurface(compositor);
_visual = compositor.CreateSpriteVisual();
_visual.RelativeSizeAdjustment = Vector2.One;
_visual.Brush = compositor.CreateSurfaceBrush(surface);
ElementCompositionPreview.SetElementChildVisual(VisualGrid, _visual);
_capture.StartCapture();
}