C#中通过FORM窗体进行简单的加减乘除计算

C#中通过FORM窗体进行简单的加减乘除计算

1. 如图

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 WindowsFormsApp2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }
        private void button3_Click(object sender, EventArgs e)
        {
            string str1 = this.textBox1.Text;
            string str2 = this.textBox2.Text;
            string str3 = this.textBox3.Text;
            int num1 = Convert.ToInt32(str1);
            int num2 = Convert.ToInt32(str2);
            int result = num1 + num2;
            textBox3.Text = Convert.ToString(result);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string str1 = this.textBox1.Text;
            string str2 = this.textBox2.Text;
            string str3 = this.textBox3.Text;
            int num1 = Convert.ToInt32(str1);
            int num2 = Convert.ToInt32(str2);
            int result = num1 -num2;
            textBox3.Text = Convert.ToString(result);
        }
        
        private void button2_Click(object sender, EventArgs e)
        {
            string str1 = this.textBox1.Text;
            string str2 = this.textBox2.Text;
            string str3 = this.textBox3.Text;
            int num1 = Convert.ToInt32(str1);
            int num2 = Convert.ToInt32(str2);
            int result = num1 *num2;
            textBox3.Text = Convert.ToString(result);
        }

        private void button4_Click(object sender, EventArgs e)
        {
            string str1 = this.textBox1.Text;
            string str2 = this.textBox2.Text;
            string str3 = this.textBox3.Text;
            int num1 = Convert.ToInt32(str1);
            int num2 = Convert.ToInt32(str2);
            double  result = num1 /num2;
            textBox3.Text = Convert.ToString(result);
        }
    }
}