chochenlu

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 WindowsFormsApplication2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{

double number1 = double.Parse(textBox1.Text);
double number2 = double.Parse(textBox2.Text);
string op = button1.Text;
double result = 0;
switch (op)
{
case "+": result = number1 + number2; break;
}
label2.Text = result.ToString();
}

private void button2_Click(object sender, EventArgs e)
{
double number1 = double.Parse(textBox1.Text);
double number2 = double.Parse(textBox2.Text);
string op = button2.Text;
double result = 0;
switch (op)
{
case "-": result = number1 - number2; break;
}
label2.Text = result.ToString();

}

private void button3_Click(object sender, EventArgs e)
{
double number1 = double.Parse(textBox1.Text);
double number2 = double.Parse(textBox2.Text);
string op = button3.Text;
double result = 0;
switch (op)
{
case "*": result = number1 * number2; break;
}
label2.Text = result.ToString();
}

private void button4_Click(object sender, EventArgs e)
{
double number1 = double.Parse(textBox1.Text);
double number2 = double.Parse(textBox2.Text);
string op = button4.Text;
double result = 0;
switch (op)
{
case "/": result = number1 / number2; break;

}
label2.Text = result.ToString();
if (label2 == null)
return;
}
}
}