图片上传(ASP.NET)

HTTP方式图片上传,文件下载

 for (int i = 0; i < iTotal; i++)
            {
                try
                {
                    
                    //取得上传文件信息，并替换其名称
                    HttpPostedFile file = context.Request.Files[i];
                    sFile = Path.GetFileName(file.FileName);
                    sFile = sFile.Substring(sFile.LastIndexOf("."));                
                    string datatime = System.DateTime.Now.ToString("yyyyMMddHHmmssffff");  //为了防止重名，获得日期为文件名  年月日时分秒毫秒                  
                    sFile = datatime + sFile;  //上传后文件的新名
                                        
                    //创建文件夹
                    string strDay = System.DateTime.Now.ToString("yyyyMM");
                    DirUrl = HttpContext.Current.Server.MapPath("~/img/" + strDay + "/");
                    if (!System.IO.Directory.Exists(DirUrl))      //检测文件夹是否存在，不存在则创建
                        System.IO.Directory.CreateDirectory(DirUrl);
                    _Url = "http://www.cnblogs.com/img/" + strDay + "/";   //
                    if (file.ContentLength > 0 || !string.IsNullOrEmpty(file.FileName))
                    {
                        //保存文件
                        file.SaveAs(DirUrl + sFile);
                        url = _Url + sFile;
                        reUrl = url;
                        if (context.Request.Form["Type"].ToUpper() != "NOWATER")
                        {
                            Solely.ImageWater sy = new Solely.ImageWater(url);
                            bool flag = sy.Watermark();
                            reUrl = sy.ThumbImage;
                        }
                    }
                }
                catch(Exception ex)
                {
                    url = "error";
                    context.Response.Write("<script>window.parent.Finish('" + reUrl + "');</script>");
                }
            }