c#编程练习题16，自己写的代码，大家帮我看看需不需要改进

Question

题目：窗体程序完成加减乘除四则运算，并将结果输出到对话框。public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }        private void 退出ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Dispose();
            this.Close();   
        }        private void 加法ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //input number validation
            double num1, num2,result;            bool val=InputValidation(txtNumberOne.Text, txtNumberTwo.Text);
            
            if (val)
            {
                //calculation
                double.TryParse(txtNumberOne.Text, out num1);
                double.TryParse(txtNumberTwo.Text, out num2);
                result = num1 + num2;                //output result
                MessageBox.Show(result.ToString());
            }
            else
            {
                MessageBox.Show("The input numbers are not valid,please try again.");
            }
        }
        private void 减法ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //input number validation
            double num1, num2, result;            bool val = InputValidation(txtNumberOne.Text, txtNumberTwo.Text);            if (val)
            {
                //calculation
                double.TryParse(txtNumberOne.Text, out num1);
                double.TryParse(txtNumberTwo.Text, out num2);
                result = num1 - num2;                //output result
                MessageBox.Show(result.ToString());
            }
            else
            {
                MessageBox.Show("The input numbers are not valid,please try again.");
            }
        }        private void 乘法ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //input number validation
            double num1, num2, result;            bool val = InputValidation(txtNumberOne.Text, txtNumberTwo.Text);            if (val)
            {
                //calculation
                double.TryParse(txtNumberOne.Text, out num1);
                double.TryParse(txtNumberTwo.Text, out num2);
                result = num1 * num2;                //output result
                MessageBox.Show(result.ToString());
            }
            else
            {
                MessageBox.Show("The input numbers are not valid,please try again.");
            }
        }        private void 除法ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //input number validation
            double num1, num2, result;            bool val = InputValidation(txtNumberOne.Text, txtNumberTwo.Text);            if (val)
            {
                //calculation
                double.TryParse(txtNumberOne.Text, out num1);
                double.TryParse(txtNumberTwo.Text, out num2);                if (num2 != 0)
                {
                    result = num1 / num2;
                    //output result
                    MessageBox.Show(result.ToString());
                }
                else
                {
                    MessageBox.Show("除数不可以为0，请重新输入！");
                }            }
            else
            {
                MessageBox.Show("The input numbers are not valid,please try again.");
            }
        }
        private bool InputValidation(string _num1, string _num2)
        {
            double num1, num2;
            bool val = false;
            try
            {
                val = (double.TryParse(_num1, out num1)) && (double.TryParse(_num2, out num2));
            }
            catch
            {
                new Exception();
            }
            return val;        }
    }代码还可以更简练些吗？请大家不吝赐教。另外，我没完成练习题15，是关于委托和事件的，还在研究中。稍后把代码发上来，请大家帮我参详参详。先谢啦！

Answer 1

CSDN告诉我
每天回帖即可获得10分可用分！

Answer 2

double num1, num2,result; 你这些参数都声明在外面也行的啊,不用每次都声明

Answer 3

一个方法就可以避免那么多的重复代码了，看下面的
public void compute(string strType)  //strType就是运算符号
{
     double num1, num2, result; 
     bool val = InputValidation(txtNumberOne.Text, txtNumberTwo.Text); 
     if (val) 
     { 
         //calculation 
          double.TryParse(txtNumberOne.Text, out num1); 
          double.TryParse(txtNumberTwo.Text, out num2); 
          result = num1 + strType + num2;           //output result 
          MessageBox.Show(result.ToString()); 
      } 
      else 
      { 
         MessageBox.Show("The input numbers are not valid,please try again."); 
         return;
      } }然后在