Quantity increment dont work with leterQuantity +1 dont work

Question

Some help

 

In line 10 setup IsLetterOrDigit..

 

When add some value in datagrid

 

 Line 34-39 have problem...

 

Every time add new row, if put number  it ok kolicina (quantity go up +1), if is bar code type vm1403 add new row...not kolicina (quantity) +1...why? Some help?

int cqty = Convert.ToInt32(row.Cells["kolicina"].Value) + 1;

                          if (textBox1.Text == row.Cells["bar_kod"].Value.ToString())
                          {
                              row.Cells["kolicina"].Value = cqty;

 

 

private void prijavaAction()
      {
          PullData();


          int sno = dataGridView1.Rows.Count + 1;

          SqlConnection con2 = new SqlConnection(con);

          if (textBox1.Text.All(char.IsLetterOrDigit))

          {
              string queryString = "select [bar_kod], [naziv], [cijena_sa_porezom] from dbo.roba_usluge WHERE [bar_kod] = '" + textBox1.Text + "'";// pronaci artikl u bazi
              using (SqlConnection connection = new SqlConnection(con))
              {
                  SqlCommand command = new SqlCommand(queryString, connection);
                  connection.Open();
                  SqlDataReader reader = command.ExecuteReader();

/////////////////////////////////
 errorr                 var itemAndPrice = textBox1.Text;

                  var SingleRow = (from Rows in dataGridView1.Rows.Cast() where !Rows.IsNewRow && Rows.Cells["bar_kod"].Value.ToString().ToUpper() == textBox1.Text.ToUpper() select Rows).FirstOrDefault();


                  if (reader.Read())
                  {

                      bool barcodeexist = false;
                      foreach (DataGridViewRow row in dataGridView1.Rows)
                      {
                          int cqty = Convert.ToInt32(row.Cells["kolicina"].Value) + 1;

                          if (textBox1.Text == row.Cells["bar_kod"].Value.ToString())
                          {
                              row.Cells["kolicina"].Value = cqty;
  ////////////////////////////////
                              foreach (DataGridViewRow g1 in dataGridView1.Rows)
                              {


                                  g1.Cells["ukupno"].Value = (Convert.ToDouble(g1.Cells["kolicina"].Value) * Convert.ToDouble(g1.Cells["cijena"].Value)).ToString("0.00");

                              }