int i =0;
string total = "";
int row = datagv3.Rows.Count - 1;
for (i = 0; i < row; i++)
total = datagv3.Rows[i].Cells[14].Value.ToString();
textBox1.Text = total.ToString();
int i =0;
Double total = 0;
int row = datagv3.Rows.Count - 1;
for (i = 0; i < row; i++)
{
total = total + Convert.ToDouble(datagv3.Rows[i].Cells[14].Value.ToString());
}
textBox1.Text = total.ToString();