.net 导入excel数据

/**
 *
 *在本章节中主要讲解的是如何使用OLEDB将Excel中的数据导入到数据库中
 *
 */
using System;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.IO;
using System.Text;
using System.Web;
using System.Web.UI;
private DataTable  xsldata()
        {
           if(fuload.FileName == "")
            {
                lbmsg.Text = "请选择文件";
                return null;
            }
            string fileExtenSion;
            fileExtenSion = Path.GetExtension(fuload.FileName);
            if(fileExtenSion.ToLower() != ".xls" && fileExtenSion.ToLower() != ".xlsx")
            {
                lbmsg.Text = "上传的文件格式不正确";
                return null;
            }
            try
            {
                string FileName = "App_Data/" + Path.GetFileName(fuload.FileName);
                if(File.Exists(Server.MapPath(FileName)))
                {
                    File.Delete(Server.MapPath(FileName));
                }
                fuload.SaveAs(Server.MapPath(FileName));
                //HDR=Yes，这代表第一行是标题，不做为数据使用 ，如果用HDR=NO，则表示第一行不是标题，做为数据来使用。系统默认的是YES
                string connstr2003 = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath(FileName) + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                string connstr2007 = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Server.MapPath(FileName) + ";Extended Properties=\"Excel 12.0;HDR=YES\"";
                OleDbConnection conn;
                if(fileExtenSion.ToLower() == ".xls")
                {
                    conn = new OleDbConnection(connstr2003);
                }
                else
                {
                    conn = new OleDbConnection(connstr2007);
                }
                conn.Open();
                string sql = "select * from [Sheet1$]";
                OleDbCommand cmd = new OleDbCommand(sql, conn);
                DataTable dt = new DataTable();
                OleDbDataReader sdr = cmd.ExecuteReader(); 

                dt.Load(sdr);
                sdr.Close();
                conn.Close();
                //删除服务器里上传的文件
                if(File.Exists(Server.MapPath(FileName)))
                {
                    File.Delete(Server.MapPath(FileName));
                }
                return dt;
            }
            catch(Exception e)
            {
                return null;
            }
        } 

        protected void Btn_Export_Excel_To_DB_Click(object sender, EventArgs e)
        {
            try{ 

                DataTable dt = xsldata(); 

                //dataGridView2.DataSource = ds.Tables[0];
                int errorcount = ;//记录错误信息条数
                int insertcount = ;//记录插入成功条数 

                int updatecount = ;//记录更新信息条数 

                string strcon = "server=localhost;database=database1;uid=sa;pwd=sa";
                SqlConnection conn = new SqlConnection(strcon);//链接数据库
                conn.Open(); 

                for(int i = ; i < dt.Rows.Count; i++)
                {
                    string Name = dt.Rows[i][].ToString();//dt.Rows[i]["Name"].ToString(); "Name"即为Excel中Name列的表头
                    string Sex = dt.Rows[i][].ToString();
                    int Age = Convert.ToInt32(dt.Rows[i][].ToString());
                    string Address = dt.Rows[i][].ToString();
                    if(Name != "" && Sex != "" && Age !=  && Address != "")
                    {
                        SqlCommand selectcmd = new SqlCommand("select count(*) from users where Name='" + Name + "' and Sex='" + Sex + "' and Age='" + Age + "' and Address=" + Address, conn);
                        int count = Convert.ToInt32(selectcmd.ExecuteScalar());
                        if(count > )
                        {
                            updatecount++;
                        }
                        else
                        {
                            SqlCommand insertcmd = new SqlCommand("insert into users(Name,Sex,Age,Address) values('" + Name + "','" + Sex + "'," + Age + ",'" + Address + "')", conn);
                            insertcmd.ExecuteNonQuery();
                            insertcount++;
                        }
                    }
                    else
                    {
                        errorcount++;
                    }
                }
                Response.Write((insertcount + "条数据导入成功！" + updatecount + "条数据重复！" + errorcount + "条数据部分信息为空没有导入！"));
            }
            catch(Exception ex)
            { 

            }
        }