PDF转换成二进制字符串写入 HTTP 输出流

　　最近项目需要做电子签章，需要网页打开PDF签章后保存：正好复习哈二进制和流的转换：

　　文件转换成二进制字符串写入HTTP输出流

 protected void Page_Load(object sender, EventArgs e)
        {
            try
            {
                string path = "Tett.PDF";           //获取文件名
                path = Server.MapPath(path);        //获取物理文件路径
                if (File.Exists(path) == false)
                    throw new Exception("找不到PDF文件");
                FileStream fs = File.Open(path, FileMode.Open);
                byte[] buffer = new byte[fs.Length];
                fs.Read(buffer, 0, buffer.Length);
                fs.Close();
                Response.ContentType = "application/pdf";
                Response.AddHeader("content-disposition", "filename=pdf");
                Response.AddHeader("content-length", buffer.Length.ToString());
                Response.BinaryWrite(buffer);
            }
            catch (Exception exp)
            {
                throw new Exception("错误", exp);
            }
            finally
            {
                Response.Flush();
                Response.Close();
                Response.End();
            }
        }

 　　获取HTTP传入的实体内容保存文件

string path = "Test.PDF";
                                path = Server.MapPath(path);
                                if (File.Exists(path) == false)
                                    throw new Exception("找不到PDF文件");
                                using (var inputStream = Request.InputStream)
                                {
                                    using (var flieStream = new FileStream(path, FileMode.Create))
                                    {
    //从当前流中读取所有字节并将其写入到目标流中
                                        inputStream.CopyTo(flieStream);
                                    }
                                }    

　　二进制转换成图片

 /// <summary>
        /// 二进制转换成图片
        /// </summary>
        /// <param name="Bytes"></param>
        /// <returns></returns>
        public static Bitmap BytesToBitmap(byte[] Bytes)
        {
            MemoryStream stream = null;
            try
            {
                stream = new MemoryStream(Bytes);
                return new Bitmap((Image)new Bitmap(stream));
            }
            catch (ArgumentNullException ex)
            {
                throw ex;
            }
            catch (ArgumentException ex)
            {
                throw ex;
            }
            finally
            {
                stream.Close();
            }
        }

　　图片转换成二进制　　

/// <summary>
        /// 图片转换成二进制
        /// </summary>
        /// <param name="Bitmap"></param>
        /// <returns></returns>
        public static byte[] BitmapToBytes(Bitmap Bitmap)
        {
            MemoryStream ms = null;
            try
            {
                ms = new MemoryStream();
                Bitmap.Save(ms, Bitmap.RawFormat);
                byte[] byteImage = new Byte[ms.Length];
                byteImage = ms.ToArray();
                return byteImage;
            }
            catch (ArgumentNullException ex)
            {
                throw ex;
            }
            finally
            {
                ms.Close();
            }
        }

 　流转换成文件

using (FileStream fs = new FileStream(path, FileMode.Create))
{
    byte[] bytes = new byte[stream.Length];
    int numBytesRead = 0;
    int numBytesToRead = (int)stream.Length;
    stream.Position = 0;
    while (numBytesToRead > 0)
    {
        int n = stream.Read(bytes, numBytesRead, Math.Min(numBytesToRead, int.MaxValue));
        if (n <= 0)
        {
            break;
        }
        fs.Write(bytes, numBytesRead, n);
        numBytesRead += n;
        numBytesToRead -= n;
    }
    fs.Close();
}

   文件转换成流

/// <summary> 
/// 从文件读取 Stream 
/// </summary> 
public Stream FileToStream(string fileName) 
{             
    // 打开文件 
    FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read); 
    // 读取文件的 byte[] 
    byte[] bytes = new byte[fileStream.Length]; 
    fileStream.Read(bytes, 0, bytes.Length); 
    fileStream.Close(); 
    // 把 byte[] 转换成 Stream 
    Stream stream = new MemoryStream(bytes); 
    return stream; 
}