public string SaveFile(byte[] binData, string filePath, string fileName, int type, string fileType)
       {

           ///定义并实例化一个内存流，以存放提交上来的字节数组。
           MemoryStream m = new MemoryStream(binData);
           FileStream fileStream = null;
           try
           {
               string savePath = System.Configuration.ConfigurationSettings.AppSettings["DcFilePath"];

               //不是绝对路径 
               if (savePath.IndexOf(":\\") < 0) savePath = Server.MapPath(savePath);

               //没有反斜杠
               if (!savePath.EndsWith("\\")) savePath += "\\";

               //目录
               savePath += filePath;

               //没有文件夹，创建文件夹

               if (!Directory.Exists(savePath))
               {
                   Directory.CreateDirectory(savePath);
               }

               if (type == 0)
               {
                   fileName = "\\" + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString();
               }
               if (!File.Exists(savePath + fileName + fileType))
               {
                   fileName = "\\" + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString();
               }
               fileName = fileName + fileType;
               //写文件
               fileStream = new FileStream(savePath + fileName, FileMode.Create);
               m.WriteTo(fileStream);
               StreamWriter sw=new StreamWriter(savePath+".txt");
               sw.WriteLine(binData.Length.ToString());
               sw.Close();
                return "filePath.Replace("\\", "/") + fileName.Replace("\\", "/");
           }
           catch
           {
               return "上传文件出错|1";
           }
           finally
           {
               m.Close();
               fileStream.Close();
           }

       }

有时候下面的函数会报错,也不知道什么原因.   还是用上传控件自带的转换.

#region 将文件转化成2进制流 ConvertFileStreamToByteBuffer
  /// </summary> 
  /// <param name="filename"></param> 
  /// <returns></returns> 
  public byte[] getBinaryFile(string filename)
  {
      if (File.Exists(filename))
      {
          FileStream s = null;
          try
          {
              //打开现有文件以进行读取。 
              s = File.OpenRead(filename);
              return this.ConvertStreamToByteBuffer(s);
          }
          catch
          {
              return new byte[0];
          }
          finally
          {
              s.Close();
          }
      }
      else
      {
          return new byte[0];
      }
  }
  #endregion

  #region 将流文件转化成2进制字节数组Convert FileStream Into Byte
  /// </summary> 
  /// <param name="theStream"></param> 
  /// <returns></returns> 
  public byte[] ConvertStreamToByteBuffer(System.IO.Stream theStream)
  {
      int b1;
      MemoryStream tempStream = new System.IO.MemoryStream();

      try
      {
          while ((b1 = theStream.ReadByte()) != -1)
          {
              tempStream.WriteByte(((byte)b1));
          }
          return tempStream.ToArray();
      }
      catch
      {
          return new byte[0];
      }
      finally
      {
          tempStream.Close();
      }
  }
  #endregion