public static async Task<IBuffer> SaveAsPngIntoBufferAsync(this Canvas canvas, double _scaleFactor, int dpiForImage = 200)
{
//string currentresolution = Window.Current.Bounds.Width * scaleFactor + "*" + Window.Current.Bounds.Height * scaleFactor;
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap();
await renderTargetBitmap.RenderAsync(canvas);
var pixels = await renderTargetBitmap.GetPixelsAsync();
using (IRandomAccessStream stream = new InMemoryRandomAccessStream())
{
var encoder = await
BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
byte[] bytes = pixels.ToArray();
await CoreWindow.GetForCurrentThread().Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
encoder.SetPixelData(BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Ignore,
(uint)(canvas.ActualWidth * _scaleFactor), (uint)(canvas.ActualHeight * _scaleFactor),
dpiForImage, dpiForImage, bytes);
});
await encoder.FlushAsync();
stream.Seek(0);
var buffer = WindowsRuntimeBuffer.Create((int)stream.Size);
await stream.ReadAsync(buffer, (uint)stream.Size, InputStreamOptions.None);
return buffer;
}
}
