上传多张图片出现重名

上传代码.

            string filetype = System.IO.Path.GetExtension(UploadFile.PostedFile.FileName);

            string result = "";

            string file = "";

            //检查上传文件的格式是否有效 

            if(UploadFile.PostedFile.ContentType.ToLower().IndexOf("image") >= 0)

            {

                if(UploadFile.PostedFile.ContentType.ToLower().IndexOf("image") < 0)

                {

                    result = "上传图片格式无效!";

                    return result;

                }



                //生成原图 

                System.IO.Stream oStream = UploadFile.PostedFile.InputStream;



                System.Drawing.Image oImage = System.Drawing.Image.FromStream(oStream);

                file = DateTime.Now.ToShortDateString().Replace("-", "").Replace("/", "") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString()+ GuidString.Substring(0,5) + filetype;

                string oFullName = System.Web.HttpContext.Current.Server.MapPath("http://images.cnblogs.com/") + file;//保存原图的物理路径 

                result = file;

                try

                {

                    //以不同格式保存图片 

                    if(filetype.Trim().ToLower().CompareTo(".png") == 0)

                    {

                        oImage.Save(oFullName, System.Drawing.Imaging.ImageFormat.Png);

                    }

                    else

                    {

                        oImage.Save(oFullName, System.Drawing.Imaging.ImageFormat.Jpeg);

                    }

                }

                catch(Exception ex)

                {

                    //抛出异常

                    throw ex;

                }

                finally

                {

                    //释放资源 

                    oImage.Dispose();

                    oFullName = "";



                    //oStream.Dispose();

                }

            }

            else

            {

                file = DateTime.Now.ToShortDateString().Replace("-", "").Replace("/", "") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + filetype;

                string oFullName = System.Web.HttpContext.Current.Server.MapPath("http://www.cnblogs.com/file/") + file;//保存原图的物理路径 

                result = file;

                UploadFile.PostedFile.SaveAs(oFullName);

            }

            return result;

  

上传多张图片的时候后面的图片会覆盖前面的图片.

 

http://www.cnblogs.com/downmoon/archive/2007/12/29/1019854.html 

 

添加GUID后解决问题,求解..