private void btnMultiply_Click(object sender, EventArgs e) { PhepTinh cal = new PhepTinh(); try { cal.NumberA = Convert.ToDouble(txtNumberA.Text); cal.NumberB = Convert.ToDouble(txtNumberB.Text); } catch (Exception) { if (txtNumberA.Text == "") { MessageBox.Show("Input A to calculate."); txtNumberA.Focus(); } else if (txtNumberB.Text == "") { MessageBox.Show("Input B to calculate."); txtNumberB.Focus(); } } double result = cal.PhepNhan(); lblOperator.Text = "*"; txtResultNumA.Text = txtNumberA.Text; txtResultNumB.Text = txtNumberB.Text; txtResult.Text = result.ToString(); cal = null; }
private void btnMinus_Click(object sender, EventArgs e) { PhepTinh cal = new PhepTinh(); try { cal.NumberA = Convert.ToDouble(txtNumberA.Text); cal.NumberB = Convert.ToDouble(txtNumberB.Text); } catch (Exception) { if (txtNumberA.Text == "") { MessageBox.Show("Input A to calculate."); txtNumberA.Focus(); } else if (txtNumberB.Text == "") { MessageBox.Show("Input B to calculate."); txtNumberB.Focus(); } } double result = cal.PhepTru(); lblOperator.Text = "-"; txtResultNumA.Text = txtNumberA.Text; txtResultNumB.Text = txtNumberB.Text; txtResult.Text = result.ToString(); cal = null; }