c#操作excel

 

private void CopyStream(Stream inputStream, Stream outputStream)
        {
            long bufferSize = inputStream.Length < BUFFER_SIZE ? inputStream.Length : BUFFER_SIZE;
            byte[] buffer = new byte[bufferSize];
            int bytesRead = 0;
            long bytesWritten = 0;
            while ((bytesRead = inputStream.Read(buffer, 0, buffer.Length)) != 0)
            {
                outputStream.Write(buffer, 0, bytesRead);
                bytesWritten += bufferSize;
            }
        }