关于datarow，在线等大佬


namespace _173110007
{
    public partial class frmEditData : Form
    {
        SqlConnection cnStudent = new SqlConnection("server=.;database=Students;integrated security=SSPI");
        SqlDataAdapter dastudengt;
        DataSet dsStudent;
        public frmEditData()
        {
            InitializeComponent();
        }        private void button2_Click(object sender, EventArgs e)
        {        }
        private void UpdateDisplay()
        {
            dsStudent.Tables.Add(new DataTable("student"));
            DataRow drv;
            drv=this.dstudent1.Rows[this.BindingContext[this.dstudent1,"Student"].Position];
        }
        private void frmEditData_Load(object sender, EventArgs e)
        {
            string strsql="SELECT *FROM student";
            dastudengt = new SqlDataAdapter(strsql,cnStudent);
            dsStudent = new DataSet();
            dastudengt.Fill(dsStudent,"student");
            UpdateDisplay();
        }
    }
}
drv那里的dstudent1书上根本没有，不知道哪来的，求大神指导