程序中的异常和错误处理

            int number = int.MaxValue;
            Console.WriteLine(number);
            try
            {
                unchecked
                {
                    number++;
                    Console.WriteLine("超出数值范围");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            Console.WriteLine(number);

            try
            {
                int num1 = int.Parse(txtNum1.Text);
                int num2 = int.Parse(txtNum2.Text);
                int result = num1 + num2;
                txtResult.Text = result.ToString();
            }
            catch (FormatException fExt)
            {
                MessageBox.Show("该文本框只能输入数值");
            }
            catch (OverflowException oExt)
            {
                MessageBox.Show("该文本框输入的数据过大或者过小");
                txtResult.Text = "0";
            }
            catch (Exception ex)
            {
                MessageBox.Show("有异常请注意你所输入的数据是否符合要求。");
                //MessageBox.Show(ex.Message);
            }