在数据库中 保存和获取各种文件

protected void btnUpload_Click(object sender, EventArgs e)
        {
            //获取上传的文件
            string filePath = FileUpload1.PostedFile.FileName;
            //获取上传文件名
            string filename = Path.GetFileName(filePath);
            //获取文件按的后缀名
            string ext = Path.GetExtension(filename);  
            string contenttype = String.Empty;

            //根据后缀名设置文件类型
            switch (ext)
            {
                case ".doc":
                    contenttype = "application/vnd.ms-word";
                    break;
                case ".docx":
                    contenttype = "application/vnd.ms-word";
                    break;
                case ".xls":
                    contenttype = "application/vnd.ms-excel";
                    break;
                case ".xlsx":
                    contenttype = "application/vnd.ms-excel";
                    break;
                case ".jpg":
                    contenttype = "image/jpg";
                    break;
                case ".png":
                    contenttype = "image/png";
                    break;
                case ".gif":
                    contenttype = "image/gif";
                    break;
                case ".pdf":
                    contenttype = "application/pdf";
                    break;
            }

            if (contenttype != String.Empty)
            {
                Stream fs = FileUpload1.PostedFile.InputStream;
                BinaryReader br = new BinaryReader(fs);
                Byte[] bytes = br.ReadBytes((Int32)fs.Length);
                //insert the file into database

                string strQuery = "insert into FileSaves(Name, ContentType, Data)" +"values (@Name, @ContentType, @Data)";
                SqlCommand cmd = new SqlCommand(strQuery);
                cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = filename;
                cmd.Parameters.Add("@ContentType", SqlDbType.VarChar).Value
                  = contenttype;
                cmd.Parameters.Add("@Data", SqlDbType.Binary).Value = bytes;
                InsertUpdateData(cmd);
                lblMessage.ForeColor = System.Drawing.Color.Green;
                lblMessage.Text = "File Uploaded Successfully";
            }
            else
            {
                lblMessage.ForeColor = System.Drawing.Color.Red;
                lblMessage.Text = "File format not recognised." +" Upload Image/Word/PDF/Excel formats";
            }
        }

  private Boolean InsertUpdateData(SqlCommand cmd)
        {
            String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["DemosDatabaseConnectionString"].ConnectionString;
            SqlConnection con = new SqlConnection(strConnString);
            cmd.CommandType = CommandType.Text;
            cmd.Connection = con;
            try
            {
                con.Open();
                cmd.ExecuteNonQuery();
                return true;
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
                return false;
            }
            finally
            {
                con.Close();
                con.Dispose();
            }
        }