Datagridview adds up unwanted rows

Question

The last line of this code is supposed to fill in a row with 3 columns in a datagridview every time the variable "temperature" and "umidita" are shown in the relevant text boxes.

These data comes from the serial port and get updated every x seconds.

private void SetText(string text)
    {
        string temperatura;
        string umidita;

        if (this.txtOutput.InvokeRequired)
        {
            SetTextCallback d = new SetTextCallback(SetText);
            this.BeginInvoke(d, new object[] { text });
        }

        else
        {

            string f = text;
            char firstChar = f[0];

            if (firstChar == 'T')
            {
                temperatura = f;
                temperatura = f.Replace("T", "");
                textBox1.Text = temperatura;
            }

            else if (firstChar == 'U')
            {
                umidita = f;
                umidita = f.Replace("U", "");
                textBox2.Text = umidita;
            }
            dataGridView1.Rows.Add(new string[] { DateTime.Now.ToString("HH:mm:ss"), textBox1.Text, textBox2.Text });
        }
    }

The code is working but I get 3 rows at time filled in with the same data.

I am not familiar with datagridview and I do not understand why I am getting such behavior. What do I need to change to get one row at time filled in with time, "temperatura" and "umidita"?

Answer 1

////you can check if you already inserted a row in this time

int rowsCount = dataGridView1.Rows.Count;
        string cuurentTime = DateTime.Now.ToString("HH:mm:ss");
        if (cuurentTime != dataGridView1.Rows[rowsCount - 1].Cells[0].Value.ToString())
        {
            dataGridView1.Rows.Add(new string[] { cuurentTime, textBox1.Text, textBox2.Text });
        }