Steps
To create a simple calculator follow the below steps.
Step 1
Design the form as shown in the below figure.
In the above design, I have taken one text box control and all the remaining are button controls.
Note
Give the proper naming conventions for each control Step 2
Double click on the all the button controls and raise the click events.
Now, write the following code.
[csharp]
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 WindowsFormsApplication30
{
public partial class Form1 : Form
{
int a, b;
string s;
double result;
public Form1()
{
InitializeComponent();
}
private void btn_1_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_1.Text;
}
private void btn_2_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_2.Text;
}
private void btn_3_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_3.Text;
}
private void btn_4_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_4.Text;
}
private void btn_5_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_5.Text;
}
private void btn_6_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_6.Text;
}
private void btn_7_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_7.Text;
}
private void btn_8_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_8.Text;
}
private void btn_9_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_9.Text;
}
private void btn_0_Click(object sender, EventArgs e)
{
txtbx.Text = txtbx.Text + btn_0.Text;
}
private void btn_add_Click(object sender, EventArgs e)
{
s = "+";
a = int.Parse(txtbx.Text);
txtbx.Text = "";
}
private void btn_sub_Click(object sender, EventArgs e)
{
s = "-";
a = int.Parse(txtbx.Text);
txtbx.Text = "";
}
private void btn_mul_Click(object sender, EventArgs e)
{
s = "*";
a = int.Parse(txtbx.Text);
txtbx.Text = "";
}
private void btn_div_Click(object sender, EventArgs e)
{
s = "/";
a = int.Parse(txtbx.Text);
txtbx.Text = "";
}
private void btn_sqrt_Click(object sender, EventArgs e)
{
s = "^";
a = int.Parse(txtbx.Text);
txtbx.Text = "";
}
private void btn_result_Click(object sender, EventArgs e)
{
b = int.Parse(txtbx.Text);
switch (s)
{
case "+":
result = a + b;
txtbx.Text = result.ToString();
break;
case "-":
result = a - b;
txtbx.Text = result.ToString();
break;
case "*":
result = a * b;
txtbx.Text = result.ToString();
break;
case "/":
result = a / b;
txtbx.Text = result.ToString();
break;
case "^":
result = Math.Pow(a, b);
txtbx.Text = result.ToString();
break;
}
}
private void btn_clear_Click(object sender, EventArgs e)
{
s = null;
a = 0;
b = 0;
result = 0;
txtbx.Text = "";
}
private void btn_ON_Click(object sender, EventArgs e)
{
btn_0.Enabled = btn_1.Enabled = btn_2.Enabled = btn_3.Enabled = btn_4.Enabled = btn_5.Enabled = btn_6.Enabled = btn_7.Enabled = btn_8.Enabled = btn_9.Enabled = btn_add.Enabled = btn_clear.Enabled = btn_div.Enabled = btn_mul.Enabled = btn_sqrt.Enabled = btn_sub.Enabled = true;
}
private void btn_OFF_Click(object sender, EventArgs e)
{
btn_0.Enabled = btn_1.Enabled = btn_2.Enabled = btn_3.Enabled = btn_4.Enabled = btn_5.Enabled = btn_6.Enabled = btn_7.Enabled = btn_8.Enabled = btn_9.Enabled = btn_add.Enabled = btn_clear.Enabled = btn_div.Enabled = btn_mul.Enabled = btn_sqrt.Enabled = btn_sub.Enabled = false;
}
private void btn_delete_Click(object sender, EventArgs e)
{
string d = txtbx.Text;
if (d.Length > 1)
{
d = d.Substring(0, d.Length - 1);
}
else
{
d = "0";
}
txtbx.Text = d;
}
private void Form1_Load(object sender, EventArgs e)
{
}
}
}
[/csharp]
Step 3
Press f5 to run the application.
Now, perform the operation.
The calculator works as real time calculator. The calculator looks like the following figure.
