async public Task CopyFromStreamASync(Stream SourceStream)
{
int BufferSize = 1024;
var Buffer = new byte[BufferSize];
while (true)
{
int Readed = await SourceStream.ReadAsync(Buffer, 0, BufferSize);
if (Readed <= 0) break;
await WriteAsync(Buffer, 0, Readed);
if (SourceStream.Position >= SourceStream.Length) break;
}
}