在上傳按鈕的事件裡：

//檔案上傳

        protected void btn_Click(object sender, EventArgs e)

        {

            if (FileUpload1.HasFile)//判斷是否存在檔案

            {

                string FilePath = Server.MapPath("/Images/");//獲取影象存的路徑

                string Extension = Path.GetExtension(FileUpload1.PostedFile.FileName);//獲取檔案的型別

                if (Extension == ".jpg" || Extension == ".png" || Extension == ".jif")//判斷格式               {

                    string NewFilePath = DateTime.Now.ToString("yyyyMMddHHmmss") + Extension;//重新命名圖片

                    FileUpload1.SaveAs(FilePath + NewFilePath);//圖片存到對應路徑

                    string

                    //Image1.ImageUrl = "../Images/" + FileUpload1.FileName;

                    Image1.ImageUrl = ImgPath;//圖片顯示

                    return;

                }

                else

                {

                    this.Page.ClientScript.RegisterStartupScript(Page.GetType(), "提示！"

                }

            }

        }