BrrrBayBay.PwmGUIControl.RcPwmControl.frequencyBox_KeyPress C# (CSharp) Метод

        void frequencyBox_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char) Keys.Return)
            {
                try
                {
                    int val = Convert.ToInt32(frequencyBox.Text);
                    if ((val < MIN_Frequency) || (val > MAX_Frequency))
                    {
                        MessageBox.Show("Please enter a frequency between " + MIN_Frequency.ToString() + " Hz and " + MAX_Frequency.ToString() + " Hz.", "Invalid PWM frequency", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        e.Handled = true;
                        return;
                    }

                    pwmFrequency = val;
                    settingsChanged = true;

                    frequencyBox.Visible = false;
                    frequencyLabel.Visible = true;
                }
                catch
                {
                    MessageBox.Show("Invalid frequency value", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
                e.Handled = true;
            }

            if (e.KeyChar == (char)Keys.Escape)
            {
                frequencyBox.Visible = false;
                frequencyLabel.Text = pwmFrequency.ToString();
                frequencyLabel.Visible = true;
                e.Handled = true;
            }
        }