C#实现附件上传和下载功能

通常情况下，我们会遇到各种上传附件的情况，以及上传后需要下载，文档格式各种各样，当然这个过程中也是报不同错误，还是一个原则，具体问题，具体分析：需求图：

上传代码实现：
 aspx代码：

 
   

   
整体活动效果:
   
   
  

cs代码：  

#region///上传，文件名称添加数据库，文件保存相应路径
 /// 

 /// 添加附件
 /// 
 /// 
 /// 
 protected void btnimport_Click(object sender, EventArgs e)
 {
  string res = "0";
  string fileName = UpLoadTxt.FileName;//获取要导入的文件名 
  if (fileName == null || fileName == "")
  {
  res = "2";
  }
  else
  {
  string savePath = Server.MapPath("~/UploadFiles/ChatLog/");
  FileOperatpr(fileName, savePath);
  string url = savePath + fileName;
  UpLoadTxt.SaveAs(url);
  SqlConnection conn = SqlHelperEx.ConnOpen("SPSDB");
  string ExtName = getFileExt(fileName).ToUpper();//获取上传文件名称
  // string ENDNmae = getFileEND(fileName).ToUpper(); //后缀名
  id = Request["id"];
  res = GetAccessory(conn, fileName, id);
  SqlHelperEx.ConnClose(conn);
  }
  if (res == "2")
  {
  Response.Write("");
  }
  if (res == "0")
  {
  Response.Write("");
  }
  if(res=="1") {
  Response.Write("");
  }
  if (res == "3")
  {
  Response.Write("");
  }
 }
 #region 辅助功能
 /// 

 /// 获取上传文件的后缀名
 /// 
 /// 
 /// 
 private string getFileEND(string fileName)
 {
  if (fileName.IndexOf(".") == -1)
  return "";
  string[] temp = fileName.Split('.');
  return temp[temp.Length - 1].ToLower();
 }
 /// 

 /// //获取上传文件的名称
 /// 
 /// 
 /// 
 private string getFileExt(string fileName)
 {
  if (fileName.IndexOf(".") == -1)
  return "";
  string file = "";
  string[] temp = fileName.Split(new[] { "." }, StringSplitOptions.RemoveEmptyEntries);
  file = temp[0].ToLower();
 return file.ToLower();
 }

 
 private void FileOperatpr(string fileName, string savePath)
 {
  if (!Directory.Exists(savePath))
  {
  Directory.CreateDirectory(savePath);
  }
  if (File.Exists(savePath + fileName))
  {
  File.Delete(savePath + fileName);
  }
 }
 
 #endregion
 
 /// 

 /// 添加文件名
 /// 
 /// 
 /// 
 /// 
 private string GetAccessory(SqlConnection conn, string filename, string id)
 {
  string res = "0";
  if (id == "0" || id == "" || id == null)
  {
  res = "3";
  }
  else
  {
  if (filename == null || filename == "")
  {
   res = "2";
  }
  else
  {
   string strOrderID = id;
   string strFileName = filename;
  string strCreateUserId = Session["UserName"].ToString();
   StringBuilder strSql = new StringBuilder();
   // 生成SQL语句;
   strSql.AppendFormat("INSERT INTO baseSNSAccessory(OrderID,FileName,CreateUserId) values( {0}", Environment.newline);
   strSql.AppendFormat(" @OrderID,@FileName,@CreateUserId) {0}", Environment.newline);
   SqlParameter[] parameters = {
      new SqlParameter("@OrderID", strOrderID),
      new SqlParameter("@FileName", strFileName),
      new SqlParameter("@CreateUserId", strCreateUserId),
      };
   // 执行
   int result = SqlHelperEx.ExecuteNonQuery(strSql.ToString(), conn, parameters);
   // 返回
   SqlHelperEx.ConnClose(conn);
  if (result == 1)
   {
   res = "1";
   }
   else
   {
   res = "0";
   }
  }
  }
  return res;
 }
 #endregion

下载实现：

 /// 

 /// 获取附件
 /// 
 /// 
 /// 
 public void GetAccessory(SqlConnection conn, string id)
 {
  string strsql = "SELECT *,(SELECT OrderName FROM Order_Info WHERe IsValid=1 AND id=bs.OrderID AND IsValid=1) AS OrderName FROM baseSNSAccessory AS bs WHERe bs.IsValid=1 and bs.OrderID="+id+" ORDER BY bs.id DESC";
  DataTable dt = SqlHelperEx.GetDataTable(strsql, conn);
 if (dt.Rows.Count == 0)
  {
  Ltlog.Text = "无数据";
  return;
  }
  string fileName = "";
  string str = "";
  for (int i = 0; i < dt.Rows.Count; i++)
  {
  fileName = dt.Rows[i]["FileName"].ToString();
  str += "";
  str += "" + dt.Rows[i]["OrderName"].ToString() + "";
  str += " 点击下载：" + fileName + "";
  str += " ";
  }
  LtOrdersory.Text = str.ToString();
 
  //string filePath = "";
 
  //FileStream fs = new FileStream(filePath, FileMode.Open); // 设置文件流,filePath为文件路径
  //byte[] bytes = new byte[(int)fs.Length];
  //fs.Read(bytes, 0, bytes.Length); // 读取
  //fs.Close();
  //Response.ClearContent(); // 清楚缓冲区所有内容
  //Response.ClearHeaders(); // 清楚缓冲区所有头
  //Response.ContentType = "application/octet-stream"; // 设置输出流的Http MIME类型
  ////通知浏览器下载文件而不是打开
  //Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)); //fileName为需要下载的文件名
  //Response.BinaryWrite(bytes); // 写入输入流
  //Response.Flush(); // 向客户端发送数据流
  //Response.End();
 }

以上就是为大家分享的C#实现附件上传和下载功能的关键代码，希望对大家的学习有所帮助。