努力循环一个datagridviewrows列表或数组，如何循环一个datagridviewrow列表？

Question

heres an image 我收到“ System.NullReferenceException，System.Windows.Forms.DataGridViewCell.Value.get返回空值”。当我尝试访问数组中某个单元格的值时出现错误，基本上我想做的是创建2个行数组，然后将datagridview3行传递给它们，如果未选中复选框，则 循环这些数组以将数据发送到数据库。编辑：它显示数组索引为-1

        DataGridViewRow[] x = new DataGridViewRow[dataGridView3.Rows.Count];
        DataGridViewRow[] y = new DataGridViewRow[dataGridView3.Rows.Count];


            if (Convert.ToBoolean(dataGridView3.Rows[row].Cells[onayver.Index].Value) == true)
            {

                x[row] = dataGridView3.Rows[row];


            }
            else if (Convert.ToBoolean(dataGridView3.Rows[row].Cells[reddettt.Index].Value) == true)
            {
                red.Add(dataGridView3.Rows[row]);
            }

        }
        MessageBox.Show(x.Count().ToString());

        for (int r = 0; r < x.Count(); r++)
        {
            infos.randevuisim = x[r].Cells[nameofistek.Index].Value.ToString(); //the error is right here
            infos.randevuzaman = x[r].Cells[timeofistek.Index].Value.ToString();
            infos.randevukulid = Convert.ToInt32(x[r].Cells[kullaniciofistek.Index].Value.ToString());


            Operations.IstekOnayla(infos.randevuisim, infos.randevuzaman, infos.randevukulid);


            Operations.KullaniciIstekGoster(dataGridView3);
            dataGridView3.AutoResizeColumns();

        }