Save Data in LINQ from two Table

 int nxnId = -1;

            using (var db = new dbDataContext())
            {
                var query = new TblNxenesi() { Emri = txtEmri.Text, Mbiemri = txtMbiemri.Text };
                db.TblNxenesis.InsertOnSubmit(query);
                db.SubmitChanges();
                nxnId = query.Nnr;
                
                foreach (DataRow row in dataGridView1.Rows)
                {
                    var query1 = new TblNota();
                    query1.Lenda = row["Lenda"].ToString();
                    query1.Nota = (int)row["Nota"];
                    query1.Nnr = nxnId;

                    db.TblNotas.InsertOnSubmit(query1);
                   
                } 
                db.SubmitChanges();
            }

I have this  problem: in field

 foreach (DataRow row in dataGridView1.Rows)

I have this error message :    " Unable to cast object of type 'System.Windows.Forms.DataGridViewRow' to type'System.Data.DataRow'" I NEED YOUR HELP!