C#

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Data.OleDb;

public partial class excelform : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // Create connection string variable. Modify the "Data Source"
        // parameter as appropriate for your environment.
        string conn = ("Provider=Microsoft.Jet.OLEDB.4.0;" +
              ("Data Source=" + Server.MapPath("excelsht.xlsx") +
            // or use instead of Excel 8.0 - Excel 5.0
              ";Extended Properties=\"Excel 8.0;\""));
        string SSQL = "SELECT * from [excelsht$]";

        // here use oleDataReader
        OleDbDataAdapter oleDA = new OleDbDataAdapter(SSQL, conn);
        DataSet ds = new DataSet();
         oleDA.Fill(ds);
        GridView1.DataSource = ds.Tables[0].DefaultView; 
        GridView1.DataBind();  
    }
}