using System.Data.OleDb;    //命名空间
        private void button1_Click(object sender, EventArgs e) 
       {            
            string strConn = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=student.xls; Extended Properties=Excel 8.0;"; 
            OleDbConnection conn = new OleDbConnection(strConn)
            string sql = "select * from [student$]";   //注意EXCEL数据库表形式
            OleDbCommand cmd = new OleDbCommand(sql, conn); 
            OleDbDataAdapter oda = new OleDbDataAdapter(cmd); 
            DataSet ds = new DataSet();  
            oda.Fill(ds,"student");  
            dataGridView1.DataSource= ds.Tables[0];      
   }