复制新文件

    /// <summary>
    ///  创建新文件流对象
    /// </summary>
    /// <param name="zipInputStream">文件流</param>
    /// <returns>新文件流对象</returns>
    private Stream CopyStream(Stream stream)
    {
        MemoryStream memstream = new MemoryStream();
        byte[] buffer = new byte[4096];
        int size = 4096;
        while (true)
        {
            size = stream.Read(buffer, 0, buffer.Length);
            if (size > 0)
            {
                memstream.Write(buffer, 0, size);
            }
            else
            {
                break;
            }
        }
        return memstream;
    }