代码如下:
protected void Button1_Click(object sender, EventArgs e)
        {

            if (FileUpload1.HasFile == false)
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "shifou", "<script>alert('请您选择   Excel文件')</script> ");
                return;
            }
            string Name = FileUpload1.PostedFile.FileName; //获取初始文件名
            int j = Name.LastIndexOf("."); //取得文件名中最后一个"."的索引
            string newext1 = Name.Substring(j); //获取文件扩展名
            if (newext1 != ".xls" && newext1 != ".xlsx")
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "wenjian", "<script>alert('只可以选择  Excel文件')</script>");
                return;//当选择的不是Excel文件时,返回
            }
            SqlConnection cn = new SqlConnection(ConfigurationManager.AppSettings["ConnectionString"]);
            cn.Open();
            //savePath = Path.GetFullPath(FileUpload1.PostedFile.FileName);//    FileUpload1.PostedFile.FileName.ToString();
            if (FileUpload1.HasFile == false)//HasFile用来检查FileUpload是否有指定文件
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "wenjian", "<script>alert('Excel路径有  问题')</script>");
                return;//当无文件时,返回
            }

            filename = FileUpload1.FileName;  //Path.GetFileNameWithoutExtension  (FileUpload1.PostedFile.FileName);
            savePath = Server.MapPath(("../../UploadFiles/xls/") + filename);
            FileUpload1.SaveAs(savePath); //保存XLS文件

            DataSet ds = ExecleDs(savePath, filename);          //调用自定义方法
            DataRow[] dr = ds.Tables[0].Select();            //定义一个DataRow数组
            int rowsnum = ds.Tables[0].Rows.Count;
            if (rowsnum == 0)
            {
                //当Excel表为空时,对用户进行提示
                Page.ClientScript.RegisterStartupScript(this.GetType(), "kong", "<script>alert('Excel表为空表,   无数据!')</script>");
            }
            else
            {
                    for (int i = 0; i < dr.Length; i++)
                    {

　　　　　　　　//自定义的model-student
                        student.belong = "";
                        student.birthday = Convert.ToDateTime("1990-1-1");
                        student.classid = 1;
                        student.id = 1;
                        student.inschool = Convert.ToDateTime("1990-1-1");
                        student.phone = "";
                        student.sex = "";
                        student.type = "";
                        student.isaudite = "否";
                        student.roleid = Convert.ToInt32("22");
                        try
                        {
                            student.stuname = dr[i]["姓名"].ToString();
                            student.stuid = dr[i]["学号"].ToString();
                            student.username = dr[i]["姓名"].ToString();
                            student.userpassword = dr[i]["学号"].ToString();
                        }
                        catch(Exception ex) {
                            Response.Write("<script>alert('"+ex.Message+"')</script>");
                            return;
                        }
                        DataSet ds2 = studentbll.GetList("stuid='" + dr[i]["学号"].ToString() + "'");
                        if (ds2.Tables[0].Rows.Count == 0)
                        {
                            try
                            {
                                bool addstudent = Convert.ToBoolean(studentbll.Add(student));
                                if (addstudent)
    Page.ClientScript.RegisterStartupScript(this.GetType(), "daochu",     "<script>alert('Excle表导入成功!')</script>");
                            }
                            catch (MembershipCreateUserException ex)       //捕捉异常
                            {
                                Page.ClientScript.RegisterStartupScript(this.GetType(), "chongfu",      "<script>alert('导入内容:" + ex.Message + "')</script> ");
                            }
                        }
                        else
                        {
                            Page.ClientScript.RegisterStartupScript(this.GetType(), "chongfu", "<script>alert    ('内容重复！禁止导入')</script> ");
                            continue;
                        }
                    }
            }
        }

  public DataSet ExecleDs(string filenameurl, string table)
        {
            string strConn = "Provider=Microsoft.Jet.Oledb.4.0;Data Source=" + filenameurl + ";Extended Properties='Excel 8.0;HDR=YES;IMEX=1;'";//这段字符串注意空格别写错否则会报错
            OleDbConnection conn = new OleDbConnection(strConn);
            OleDbDataAdapter odda = new OleDbDataAdapter("select * from [Sheet18$]", conn);//【sheet18$】是表格名

            DataSet ds = new DataSet();
            odda.Fill(ds, table);
            return ds;
        }