TemporaryFile.cs

internal class TemporaryFile : IDisposable
    {
        private readonly FileInfo _fileInfo;
        private bool _disposed;

        public TemporaryFile(string extension = "tmp")
        {
            _fileInfo = CreateFilename(extension);
        }

        private static FileInfo CreateFilename(string extension)
        {
            return new FileInfo(Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N") + "." + extension));
        }

        private TemporaryFile(FileInfo file)
        {
            _fileInfo = file;
        }

        public static async Task<TemporaryFile> Create(Stream stream, string extension = "tmp")
        {
            var file = CreateFilename(extension);

            using (stream)
            using (var destination = file.OpenWrite())
                await stream.CopyToAsync(destination);

            return new TemporaryFile(file);
        }

        public TemporaryFile(Stream stream, string extension = "tmp")
            : this(extension)
        {
            using (stream)
            using (var destination = _fileInfo.OpenWrite())
                stream.CopyTo(destination);
        }

        public FileInfo Info
        {
            get { return _fileInfo; }
        }

        protected virtual void Dispose(bool disposing)
        {
            if (_disposed)
                return;
            try
            {
                _fileInfo.Delete();
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex);
            }
            _disposed = true;

        }

        ~TemporaryFile()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        public async Task CopyTo(Stream result)
        {
            using (var stream = _fileInfo.OpenRead())
                await stream.CopyToAsync(result);

            if (result.CanSeek)
                result.Seek(0, SeekOrigin.Begin);
        }
    }