Question

Create a windows form application in c#

The form must look like a calculator and do the following.

Add, subtract, multiply, and divide.

Account for division by zero.

Show at least two decimal places.

Retain the last number on the window so that, when the user opens the calculator the next time, the number that was in the window at the last close appears.

Have a memory, so that users can store values and recall them.

Operate with a mouse clicking buttons

Operate from the keyboard only with no mouse requirement.

Contain a small box for the company logo. Make up a logo and insert it there.

Contain a clear and clear all button.

The user must NOT be able to enter data directly in the display window – they have to press the keys.

Look like a calculator, and not a maximized window.

Use naming conventions for all the elements on the form. In other words, do not use the default names for the labels, buttons, or other controls.

Answer 1

using System;
using System.Collections.Generic;
using System.Component Model;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
  
namespace Calculator
{
public partial class Form1 : Form
{
double FirstNumber;
string Operation;
public Form1()
{
InitializeComponent();
}
  

private void n1_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "1";
}
else
{
textBox1.Text = textBox1.Text + "1";
}
}
  
private void n2_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "2";
}
else
{
textBox1.Text = textBox1.Text + "2";
}
}
  
private void n3_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "3";
}
else
{
textBox1.Text = textBox1.Text + "3";
}
}
  
private void n4_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "4";
}
else
{
textBox1.Text = textBox1.Text + "4";
}
}
  
private void n5_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "5";
}
else
{
textBox1.Text = textBox1.Text + "5";
}
}
  
private void n6_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "6";
}
else
{
textBox1.Text = textBox1.Text + "6";
}
}
  
private void n7_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "7";
}
else
{
textBox1.Text = textBox1.Text + "7";
}
}
  
private void n8_Click(object sender, EventArgs e)
{
if (textBox1.Text == "0" && textBox1.Text != null)
{
textBox1.Text = "8";
}
else
{
textBox1.Text = textBox1.Text + "8";
}
}
  
private void n9_Click(object sender, EventArgs e)
{
if (textBox1.Text == "" && textBox1.Text != null)
{
textBox1.Text = "9";
}
else
{
textBox1.Text = textBox1.Text + "9";
}
}
  
private void n0_Click(object sender, EventArgs e)
{
textBox1.Text = textBox1.Text + "0";
}
  
private void bad_Click(object sender, EventArgs e)
{
FirstNumber = Convert.ToDouble(textBox1.Text);
textBox1.Text = "0";
Operation = "+";
}
  
private void bsub_Click(object sender, EventArgs e)
{
FirstNumber = Convert.ToDouble(textBox1.Text);
textBox1.Text = "0";
Operation = "-";
  
}
  
private void bmul_Click(object sender, EventArgs e)
{
FirstNumber = Convert.ToDouble(textBox1.Text);
textBox1.Text = "0";
Operation = "*";
}
  
private void bdiv_Click(object sender, EventArgs e)
{
FirstNumber = Convert.ToDouble(textBox1.Text);
textBox1.Text = "0";
Operation = "/";
}
  
private void bc_Click(object sender, EventArgs e)
{
textBox1.Text = "0";
}
  
private void ndot_Click(object sender, EventArgs e)
{
textBox1.Text = textBox1.Text + ".";
}
  
private void nequal_Click(object sender, EventArgs e)
{
double SecondNumber;
double Result;
  
SecondNumber = Convert.ToDouble(textBox1.Text);
  
if (Operation == "+")
{
Result = (FirstNumber + SecondNumber);
textBox1.Text = Convert.ToString(Result);
FirstNumber = Result;
}
if (Operation == "-")
{
Result = (FirstNumber - SecondNumber);
textBox1.Text = Convert.ToString(Result);
FirstNumber = Result;
}
if (Operation == "*")
{
Result = (FirstNumber * SecondNumber);
textBox1.Text = Convert.ToString(Result);
FirstNumber = Result;
}
if (Operation == "/")
{
if (SecondNumber == 0)
{
textBox1.Text = "Cannot divide by zero";
  
}
else
{
Result = (FirstNumber / SecondNumber);
textBox1.Text = Convert.ToString(Result);
FirstNumber = Result;
}
}
}
}
}