简单加法计算器(C#)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace frmexe01
{
    public partial class frmexe01 : Form
    {
        public frmexe01()
        {
            InitializeComponent();
        }

        private void frmexe01_Load(object sender, EventArgs e)
        {

        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {

        }

        private void btnComputer_Click(object sender, EventArgs e)
        {
            int number1, number2;
            if(int.TryParse(txtNumber1.Text,out number1) == false)
            {
                //说明转换不成功
                MessageBox.Show("输入的第一个加数有问题!");
                txtNumber1.SelectAll();
                txtNumber1.Focus();
                return;
            }

            if (int.TryParse(txtNumber2.Text, out number2) == false)
            {
                //说明转换不成功
                MessageBox.Show("输入的第二个加数有问题!");
                txtNumber2.SelectAll();
                txtNumber2.Focus();
                return;
            }

            int sum = number1 + number2;
            txtResult.Text = sum.ToString();
        }

        private void txtNumber1_TextChanged(object sender, EventArgs e)
        {
            txtResult.Text = "";
        }
    }
}

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace computer
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
        }

        private void btnJisuan_Click(object sender, EventArgs e)
        {
            try
            {
                double chang = Convert.ToDouble(txtChang.Text);
                double kuan = Convert.ToDouble(txtKuan.Text);
                double mianji = chang * kuan;
                lbResult.Text = mianji.ToString();
            }
            catch (Exception ex)
            {
                MessageBox.Show("计算时发生错误.错误原因:" + ex.Message);
            }
        }
    }
}