WinForms App - CALCULATOR

try
            {
                decimal num1 = decimal.Parse(this.textBox1.Text);
                decimal num2 = decimal.Parse(this.textBox2.Text);
                decimal result = 0.0m;
                string oper = this.operBox1.Text;

                switch (oper)
                {
                    case "+":
                        result = num1 + num2;
                        break;
                    case "-":
                        result = num1 - num2;
                        break;
                    case "*":
                        result = num1 * num2;
                        break;
                    case "/":
                        result = num1 / num2;
                        break;
                    case "%":
                        result = num1 % num2;
                        break;
                    default:
                        break;
                }

                // string.Format("Number: {0:N}", 157); // result: 157,00
                textBoxResult.Text = result.ToString();
            }
            catch (Exception)
            {
                textBoxResult.Text = "Грешка";
            }