Auto refresh datagrid after insert value?

Question

Auto refresh datagrid after insert value?

 

private void dataGridView1_SelectionChanged(object sender, EventArgs e)
       {
           double[] columnData = new double[dataGridView1.Rows.Count];
           columnData = (from DataGridViewRow row in dataGridView1.Rows
                         where row.Cells["kolicina"].FormattedValue.ToString() != string.Empty
                         select Convert.ToDouble(row.Cells["kolicina"].FormattedValue)).ToArray();
           kolicinalabel.Text = columnData.Sum().ToString("#,0.00");
           button3_Click(null, null);



           double[] columnData2 = new double[dataGridView1.Rows.Count];
           columnData = (from DataGridViewRow row in dataGridView1.Rows
                         where row.Cells["ukupno"].FormattedValue.ToString() != string.Empty
                         select Convert.ToDouble(row.Cells["ukupno"].FormattedValue)).ToArray();
           ukupnolabel.Text = columnData.Sum().ToString("#,0.00");

           dataGridView1.Refresh();

       }