.net文件上传类

using System;
using System.Collections.Generic;
using System.Text;
using System.Web.UI.WebControls;

namespace NetRoute.Test_News.Comman
{
    public class Common
    {
        public Common()
        {

        }
        /**//// <summary>
        /// 生成的文件名类别(guid,date两种)
        /// </summary>
        public enum FileNameType
        {
            Guid,
            DateTime,
        }
        private static string _Message = string.Empty;//操作消息..
        public static string Message
        {
            get { return _Message; }
        }

        static int Seed = 1;
        /**//// <summary>
        /// 上传文件
        /// </summary>
        /// <param name="_fu">文件上传控件</param>
        /// <param name="path">上传路径（不带文件名）</param>
        /// <param name="FileSize">文件大小(以字节为单位)</param>
        /// <param name="NoFile">是否允许空</param>
        /// <param name="Type">生成的文件名类型（Guid/DateTime）</param>
        /// <returns></returns>
        public static bool UploadFile(FileUpload _fu,string path,int? FileSize,bool NoFile,FileNameType Type)
        {
            bool _result = true;
            if (_fu.HasFile)
            {
                if (FileSize != null)
                {
                    if (_fu.PostedFile.ContentLength > FileSize)
                    {
                        _Message = "上传的文件过大！";
                        _result = false;
                        return _result;
                    }
                }
                string FileName = _fu.FileName;
                string FileType = _fu.PostedFile.ContentType;
                string extend = FileName.Substring((FileName.LastIndexOf('.') + 1));
                if (FileType.Substring(0,FileType.IndexOf('/')) == "image")
                {
                    try
                    {
                        if (Type == FileNameType.Guid)
                        {
                            string NewFileName = System.Guid.NewGuid().ToString() + "." + extend;
                            _fu.SaveAs(path + NewFileName);
                        }
                        else if (Type == FileNameType.DateTime)
                        {
                            Random rd = new Random(Seed);
                            string NewFileName = MakeFileName + "." + extend;
                            _fu.SaveAs(path + NewFileName);
                        }
                    }
                    catch (Exception ex)
                    {
                        _Message = ex.Message;
                        _result = false;
                    }
                }
                else
                {
                    _Message = "上传的文件格式不正确！";
                    _result = false;
                }
            }
            else
            {
                if (!NoFile)
                {
                    _result = false;
                    _Message = "您没有上传文件！";
                }

            }
            return _result;
        }

        private static int _Seed = 0;
        private static string MakeFileName
        {
            get
            {
                System.Random ran = new Random(_Seed);
                _Seed++;
                if (_Seed == 10000)
                    _Seed = 0;
                return DateTime.Now.ToFileTime().ToString() + ran.Next(1, 999).ToString();
            }
        }
        public static bool UploadFile(FileUpload _fu, string path, bool NoFile, FileNameType Type)
        {
            return UploadFile(_fu, path, null, NoFile, Type);
        }
    }
}