为每个用户创建文件夹，并实现图片上传

        /// <summary>
        /// 用户登录即为每个用户创建文件夹,userid从session获取,即登录用户ID
        /// </summary>
        protected void CreateFlord()
        {
            path = "../../uploads/Picture/" + userid;
            imgpath = Server.MapPath(path).ToString();
            if (!Directory.Exists(imgpath))
            {
                Directory.CreateDirectory(imgpath);
            }
        }

        if (!this.fuImg.HasFile)
            {
                this.PicPrompt.InnerHtml = "图片路径不能为空";
                return;
            }
            Random rd = new Random();
            filename = DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() +DateTime.Now.Millisecond.ToString() + rd.Next(100000, 999999).ToString();//当前时间+随机数以重命名图片名字
              typefilename = System.IO.Path.GetExtension(this.fuImg.FileName).ToLower();
            if (typefilename != ".jpg" & typefilename != ".gif" & typefilename != ".png")
            {
                this.PicPrompt.InnerHtml = "图片只能为jpg、gif、png格式";
                return;
            }
            this.PicPrompt.InnerHtml = "";
            this.fuImg.SaveAs(imgpath + "\\" + filename + typefilename);
            SDW.Model.Picture model_picture = new SDW.Model.Picture();
            model_picture.PicName = filename;
            model_picture.PicUrl = path + "/" + filename + typefilename;
            model_picture.PicText = this.txtPicText.Text;
            model_picture.Createdate = DateTime.Now;
            model_picture.Album = Convert.ToInt32(this.ddlAlbum.SelectedItem.Value);
            model_picture.PicUser = userid;
            AddPicture(model_picture);//将图片信息保存到数据库