protected void Button1_Click(object sender, EventArgs e)
    {

        if (fileUpload1.HasFile == false)//HasFile用来检查FileUpload是否有指定文件
        {
            Response.Write("<script>alert('请您选择Excel文件')</script> ");
            return;
        }
        string IsXls = System.IO.Path.GetExtension(fileUpload1.FileName).ToString().ToLower();//System.IO.Path.GetExtension获得文件的扩展名
        if (IsXls != ".xls" && IsXls != ".xlsx")
        {
            Response.Write("<script>alert('只可以选择Excel文件')</script>");
            return;
        }
        string filename = fileUpload1.FileName;
        string savePath = Server.MapPath(filename);//Server.MapPath 获得虚拟服务器相对路径
        fileUpload1.SaveAs(savePath);                        //SaveAs 将上传的文件内容保存在服务器上
        DataSet ds = ExcelSqlConnection(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)
        {
            Response.Write("<script>alert('Excel表为空表,无数据!')</script>");   //当Excel表为空时,对用户进行提示
        }
    }
    public static System.Data.DataSet ExcelSqlConnection(string filepath, string tableName)
    {
        DataSet ds = new DataSet();
        try
        {
            string strCon = string.Format("Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source ={0};Extended Properties=Excel 8.0", tableName);
            OleDbConnection myConn = new OleDbConnection(strCon);
            string strCom = " SELECT * FROM [Sheet1$] ";
            myConn.Open();
            //打开数据链接，得到一个数据集  
            OleDbDataAdapter myCommand = new OleDbDataAdapter(strCom, myConn);
            
            myCommand.Fill(ds, "[Sheet1$]");
            myConn.Close();
        }catch( Exception ee)
        {
            
        }

                return ds;
    }