Introduction

Here is a Windows Forms app that creates a Simple Arithmetic Calculator UI app using .NET and C#.
Sample Program
  1. using System;
  2. using System.Collections.Generic;
  3. using System.ComponentModel;
  4. using System.Data;
  5. using System.Drawing;
  6. using System.Linq;
  7. using System.Text;
  8. using System.Windows.Forms;
  10. namespace calculator1
  11. {
  12. public partial class Form1 : Form
  13. {
  14. int a=0;
  15. int b,c;
  16. string msg;
  18. public Form1()
  19. {
  20. InitializeComponent();
  21. }
  23. private void Form1_Load(object sender, EventArgs e)
  24. {
  26. }
  28. private void b1_Click(object sender, EventArgs e)
  29. {
  30. t1.Text = t1.Text + b1.Text;
  31. }
  33. private void b2_Click(object sender, EventArgs e)
  34. {
  35. t1.Text = t1.Text + b2.Text;
  36. }
  38. private void b3_Click(object sender, EventArgs e)
  39. {
  40. t1.Text = t1.Text + b3.Text;
  41. }
  43. private void b5_Click(object sender, EventArgs e)
  44. {
  45. t1.Text = t1.Text + b5.Text;
  46. }
  48. private void b6_Click(object sender, EventArgs e)
  49. {
  50. t1.Text = t1.Text + b6.Text;
  51. }
  53. private void b7_Click(object sender, EventArgs e)
  54. {
  55. t1.Text = t1.Text + b7.Text;
  56. }
  58. private void b9_Click(object sender, EventArgs e)
  59. {
  60. t1.Text = t1.Text + b9.Text;
  61. }
  63. private void b10_Click(object sender, EventArgs e)
  64. {
  65. t1.Text = t1.Text + b10.Text;
  66. }
  68. private void b11_Click(object sender, EventArgs e)
  69. {
  70. t1.Text = t1.Text + b11.Text;
  71. }
  73. private void b13_Click(object sender, EventArgs e)
  74. {
  75. t1.Text = t1.Text + b13.Text;
  76. }
  78. private void b4_Click(object sender, EventArgs e)
  79. {
  80. a = Convert.ToInt32(t1.Text);
  81. t1.Text = "";
  82. msg = "+";
  83. }
  85. private void b8_Click(object sender, EventArgs e)
  86. {
  87. a = Convert.ToInt32(t1.Text);
  88. t1.Text = "";
  89. msg = "-";
  90. }
  92. private void b12_Click(object sender, EventArgs e)
  93. {
  94. a = Convert.ToInt32(t1.Text);
  95. t1.Text = "";
  96. msg = "*";
  97. }
  99. private void b15_Click(object sender, EventArgs e)
  100. {
  101. a = Convert.ToInt32(t1.Text);
  102. t1.Text = "";
  103. msg = "/";
  104. }
  106. private void b16_Click(object sender, EventArgs e)
  107. {
  108. t1.Text = "";
  109. }
  111. private void b14_Click(object sender, EventArgs e)
  112. {
  113. if (msg == "+")
  114. {
  115. b = Convert.ToInt32(t1.Text);
  116. c = a + b;
  117. }
  119. if (msg == "-")
  120. {
  121. b = Convert.ToInt32(t1.Text);
  122. c = a - b;
  123. }
  125. if (msg == "*")
  126. {
  127. b = Convert.ToInt32(t1.Text);
  128. c = a * b;
  129. }
  131. if (msg == "/")
  132. {
  133. b = Convert.ToInt32(t1.Text);
  134. c = a / b;
  135. }
  137. t1.Text = c.ToString();
  138. }
  140. }
  141. }

Explanation


The UI of the Simple Arithmetic Calculator looks like the following where you can see, there is a button for numbers and operators. Just run the program, select your numbers and operators and run it.
Simple Calculator using .NET Window Application