How to get item value from gridview use linq binding?

     public partial class WebForm1 : System.Web.UI.Page
    {
        DataContext sqlContext = new DataContext();
        protected void Page_Load(object sender, EventArgs e)
        {
            var _Agent = from c in sqlContext.Agents
                           select c;
            GridView1.DataSource = _Agent;
            GridView1.DataBind();
        }
        protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            DataRowView dRowView = (DataRowView)e.Row.DataItem;
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                if ((e.Row.RowState & DataControlRowState.Edit) > 0)
                {
                    RadioButtonList _rblGender = (RadioButtonList)e.Row.FindControl("rblGender");
                    _rblGender.SelectedValue = dRowView[3].ToString();
                }
            }
        }
    }