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, , 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 = ;
     int numBytesToRead = (int)stream.Length;
     stream.Position = ;
     while (numBytesToRead > )
     {
         int n = stream.Read(bytes, numBytesRead, Math.Min(numBytesToRead, int.MaxValue));
         if (n <= )
         {
             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, , bytes.Length);
     fileStream.Close();
     // 把 byte[] 转换成 Stream
     Stream stream = new MemoryStream(bytes);
     return stream;
 }