给你个例子参考一下: 【前台】 #Code:
#Code 【后台】 #Code protected void Button1_Click(object sender, EventArgs e) { if (Fileupload1.HasFile == true) { string name = Fileupload1.PostedFile.FileName; FileInfo info = new FileInfo(name); string aa = Server.MapPath("/images/" + info.Name); Fileupload1.SaveAs(aa); } else { ScriptManager.RegisterStartupScript(this.Page, this.GetType(), "aa", "javascript:alert('图片不为空!')", true); } } #Code Server.MapPath获取到的是相对路径!