The Link Your Class	https://bbs.csdn.net/forums/ssynkqtd-04
The Link of Requirement of This Assignment	https://bbs.csdn.net/topics/617378696
Link to the finished project code	github
The Aim of This Assignment	Construct a back-end separation calculator
MU STU ID and FZU STU ID	<21125210_832102106>

Catalog

I. PSP form

Personal Software Process Stages	Estimated Time（minutes）	Actual Time（minutes）
Planning(total)	500	700
• Estimate	500	700
Development(total)	360	440
• Analysis	50	70
• Design Spec	15	20
• Design Review	15	20
• Coding Standard	15	20
• Design	50	60
• Coding	125	140
• Code Review	50	60
• Test	40	50
Reporting(total)	120	120
• Test Repor	10	10
• Size Measurement	10	10
• Postmortem & Process Improvement Plan	100	100
Sum	980	1260

II. Introduction

When I set out to develop a scientific calculator, my goal was to create a powerful application with data storage and retrieval capabilities. I chose to use C# and WinForms for building this application and integrated a MySQL database to store and retrieve calculation history. In this blog post, I'll share my development experience and the key features of this scientific calculator.

Link to the finished project code：Link

III. Development Environment and Technology Choices

I chose to use C# and WinForms because they provide robust tools for user interface design and seamless interaction with MySQL databases. Here are the primary technologies and tools I used:

1. C#

Serving as the primary programming language for the application, C# offers a wide range of features, including object-oriented programming, event handling, and graphical user interface design.

2. WinForms

WinForms is Microsoft's library for creating Windows desktop applications. It boasts a rich set of UI controls and an easy-to-use designer.

3. MySQL Database

I employed a MySQL database system for storing calculation history records. MySQL was my database of choice due to its open-source nature and powerful relational database capabilities.

IV. Key Features and User Interface Design

1. User-Friendly Interface

I designed an intuitive and user-friendly interface with buttons and a text box. Users can easily perform calculations and access their history records. The calculatio history is automatically updated with each calculation performed.

The code of FrmCalculator.Designer.cs:

namespace Cwk_ScientificCalculator
{
    partial class frmCalculator
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.txtDisplay = new System.Windows.Forms.TextBox();
            this.btn1 = new System.Windows.Forms.Button();
            this.btn2 = new System.Windows.Forms.Button();
            this.btn3 = new System.Windows.Forms.Button();
            this.btn4 = new System.Windows.Forms.Button();
            this.btn5 = new System.Windows.Forms.Button();
            this.btn6 = new System.Windows.Forms.Button();
            this.btn7 = new System.Windows.Forms.Button();
            this.btn8 = new System.Windows.Forms.Button();
            this.btn9 = new System.Windows.Forms.Button();
            this.btnBackspace = new System.Windows.Forms.Button();
            this.btnClear = new System.Windows.Forms.Button();
            this.button14 = new System.Windows.Forms.Button();
            this.btnPlus = new System.Windows.Forms.Button();
            this.btnSubtract = new System.Windows.Forms.Button();
            this.btnMultiply = new System.Windows.Forms.Button();
            this.btnDivide = new System.Windows.Forms.Button();
            this.btnEquals = new System.Windows.Forms.Button();
            this.btnSqrRoot = new System.Windows.Forms.Button();
            this.btnLog = new System.Windows.Forms.Button();
            this.btnMsubtract = new System.Windows.Forms.Button();
            this.btnMplus = new System.Windows.Forms.Button();
            this.btnMS = new System.Windows.Forms.Button();
            this.btnMR = new System.Windows.Forms.Button();
            this.btnMC = new System.Windows.Forms.Button();
            this.btnCloseBracket = new System.Windows.Forms.Button();
            this.btnOpenBracket = new System.Windows.Forms.Button();
            this.btnCos = new System.Windows.Forms.Button();
            this.btnSin = new System.Windows.Forms.Button();
            this.btnPowerOf = new System.Windows.Forms.Button();
            this.btnExp = new System.Windows.Forms.Button();
            this.btnTan = new System.Windows.Forms.Button();
            this.btn0 = new System.Windows.Forms.Button();
            this.btnMod = new System.Windows.Forms.Button();
            this.ans = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // txtDisplay
            // 
            this.txtDisplay.BackColor = System.Drawing.Color.MidnightBlue;
            this.txtDisplay.Font = new System.Drawing.Font("Arial", 19.8F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.txtDisplay.ForeColor = System.Drawing.Color.White;
            this.txtDisplay.Location = new System.Drawing.Point(12, 11);
            this.txtDisplay.Multiline = true;
            this.txtDisplay.Name = "txtDisplay";
            this.txtDisplay.ReadOnly = true;
            this.txtDisplay.Size = new System.Drawing.Size(399, 60);
            this.txtDisplay.TabIndex = 0;
            this.txtDisplay.Text = "0";
            this.txtDisplay.TextAlign = System.Windows.Forms.HorizontalAlignment.Right;
            // 
            // btn1
            // 
            this.btn1.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn1.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn1.ForeColor = System.Drawing.Color.White;
            this.btn1.Location = new System.Drawing.Point(12, 349);
            this.btn1.Name = "btn1";
            this.btn1.Size = new System.Drawing.Size(75, 52);
            this.btn1.TabIndex = 2;
            this.btn1.Text = "1";
            this.btn1.UseVisualStyleBackColor = false;
            this.btn1.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn2
            // 
            this.btn2.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn2.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn2.ForeColor = System.Drawing.Color.White;
            this.btn2.Location = new System.Drawing.Point(93, 349);
            this.btn2.Name = "btn2";
            this.btn2.Size = new System.Drawing.Size(75, 52);
            this.btn2.TabIndex = 3;
            this.btn2.Text = "2";
            this.btn2.UseVisualStyleBackColor = false;
            this.btn2.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn2.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn2.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn3
            // 
            this.btn3.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn3.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn3.ForeColor = System.Drawing.Color.White;
            this.btn3.Location = new System.Drawing.Point(174, 349);
            this.btn3.Name = "btn3";
            this.btn3.Size = new System.Drawing.Size(75, 52);
            this.btn3.TabIndex = 4;
            this.btn3.Text = "3";
            this.btn3.UseVisualStyleBackColor = false;
            this.btn3.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn3.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn3.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn4
            // 
            this.btn4.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn4.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn4.ForeColor = System.Drawing.Color.White;
            this.btn4.Location = new System.Drawing.Point(12, 292);
            this.btn4.Name = "btn4";
            this.btn4.Size = new System.Drawing.Size(75, 52);
            this.btn4.TabIndex = 5;
            this.btn4.Text = "4";
            this.btn4.UseVisualStyleBackColor = false;
            this.btn4.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn4.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn4.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn5
            // 
            this.btn5.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn5.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn5.ForeColor = System.Drawing.Color.White;
            this.btn5.Location = new System.Drawing.Point(93, 292);
            this.btn5.Name = "btn5";
            this.btn5.Size = new System.Drawing.Size(75, 52);
            this.btn5.TabIndex = 6;
            this.btn5.Text = "5";
            this.btn5.UseVisualStyleBackColor = false;
            this.btn5.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn5.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn5.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn6
            // 
            this.btn6.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn6.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn6.ForeColor = System.Drawing.Color.White;
            this.btn6.Location = new System.Drawing.Point(174, 292);
            this.btn6.Name = "btn6";
            this.btn6.Size = new System.Drawing.Size(75, 52);
            this.btn6.TabIndex = 7;
            this.btn6.Text = "6";
            this.btn6.UseVisualStyleBackColor = false;
            this.btn6.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn6.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn6.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn7
            // 
            this.btn7.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn7.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn7.ForeColor = System.Drawing.Color.White;
            this.btn7.Location = new System.Drawing.Point(12, 234);
            this.btn7.Name = "btn7";
            this.btn7.Size = new System.Drawing.Size(75, 52);
            this.btn7.TabIndex = 8;
            this.btn7.Text = "7";
            this.btn7.UseVisualStyleBackColor = false;
            this.btn7.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn7.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn7.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn8
            // 
            this.btn8.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn8.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn8.ForeColor = System.Drawing.Color.White;
            this.btn8.Location = new System.Drawing.Point(93, 234);
            this.btn8.Name = "btn8";
            this.btn8.Size = new System.Drawing.Size(75, 52);
            this.btn8.TabIndex = 9;
            this.btn8.Text = "8";
            this.btn8.UseVisualStyleBackColor = false;
            this.btn8.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn8.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn8.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn9
            // 
            this.btn9.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn9.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn9.ForeColor = System.Drawing.Color.White;
            this.btn9.Location = new System.Drawing.Point(174, 234);
            this.btn9.Name = "btn9";
            this.btn9.Size = new System.Drawing.Size(75, 52);
            this.btn9.TabIndex = 10;
            this.btn9.Text = "9";
            this.btn9.UseVisualStyleBackColor = false;
            this.btn9.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn9.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn9.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnBackspace
            // 
            this.btnBackspace.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnBackspace.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnBackspace.ForeColor = System.Drawing.Color.White;
            this.btnBackspace.Location = new System.Drawing.Point(93, 177);
            this.btnBackspace.Name = "btnBackspace";
            this.btnBackspace.Size = new System.Drawing.Size(75, 52);
            this.btnBackspace.TabIndex = 11;
            this.btnBackspace.Text = "⌫";
            this.btnBackspace.UseVisualStyleBackColor = false;
            this.btnBackspace.Click += new System.EventHandler(this.btnBackspace_Click);
            this.btnBackspace.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnBackspace.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnClear
            // 
            this.btnClear.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnClear.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnClear.ForeColor = System.Drawing.Color.White;
            this.btnClear.Location = new System.Drawing.Point(12, 177);
            this.btnClear.Name = "btnClear";
            this.btnClear.Size = new System.Drawing.Size(75, 52);
            this.btnClear.TabIndex = 13;
            this.btnClear.Text = "C";
            this.btnClear.UseVisualStyleBackColor = false;
            this.btnClear.Click += new System.EventHandler(this.btnClear_Click);
            this.btnClear.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnClear.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // button14
            // 
            this.button14.BackColor = System.Drawing.Color.MidnightBlue;
            this.button14.Font = new System.Drawing.Font("Microsoft Sans Serif", 16.2F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.button14.ForeColor = System.Drawing.Color.White;
            this.button14.Location = new System.Drawing.Point(12, 409);
            this.button14.Name = "button14";
            this.button14.Size = new System.Drawing.Size(75, 52);
            this.button14.TabIndex = 14;
            this.button14.Text = ".";
            this.button14.UseVisualStyleBackColor = false;
            this.button14.Click += new System.EventHandler(this.inputDot);
            this.button14.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.button14.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnPlus
            // 
            this.btnPlus.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnPlus.Font = new System.Drawing.Font("Microsoft Sans Serif", 16.2F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnPlus.ForeColor = System.Drawing.Color.White;
            this.btnPlus.Location = new System.Drawing.Point(255, 409);
            this.btnPlus.Name = "btnPlus";
            this.btnPlus.Size = new System.Drawing.Size(75, 52);
            this.btnPlus.TabIndex = 15;
            this.btnPlus.Text = " + ";
            this.btnPlus.UseVisualStyleBackColor = false;
            this.btnPlus.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnPlus.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnPlus.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnSubtract
            // 
            this.btnSubtract.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnSubtract.Font = new System.Drawing.Font("Microsoft Sans Serif", 16.2F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnSubtract.ForeColor = System.Drawing.Color.White;
            this.btnSubtract.Location = new System.Drawing.Point(255, 349);
            this.btnSubtract.Name = "btnSubtract";
            this.btnSubtract.Size = new System.Drawing.Size(75, 52);
            this.btnSubtract.TabIndex = 16;
            this.btnSubtract.Text = " - ";
            this.btnSubtract.UseVisualStyleBackColor = false;
            this.btnSubtract.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnSubtract.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnSubtract.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMultiply
            // 
            this.btnMultiply.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMultiply.Font = new System.Drawing.Font("Microsoft Sans Serif", 16.2F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnMultiply.ForeColor = System.Drawing.Color.White;
            this.btnMultiply.Location = new System.Drawing.Point(255, 292);
            this.btnMultiply.Name = "btnMultiply";
            this.btnMultiply.Size = new System.Drawing.Size(75, 52);
            this.btnMultiply.TabIndex = 17;
            this.btnMultiply.Text = " * ";
            this.btnMultiply.UseVisualStyleBackColor = false;
            this.btnMultiply.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnMultiply.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMultiply.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnDivide
            // 
            this.btnDivide.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnDivide.Font = new System.Drawing.Font("Microsoft Sans Serif", 16.2F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnDivide.ForeColor = System.Drawing.Color.White;
            this.btnDivide.Location = new System.Drawing.Point(255, 234);
            this.btnDivide.Name = "btnDivide";
            this.btnDivide.Size = new System.Drawing.Size(75, 52);
            this.btnDivide.TabIndex = 18;
            this.btnDivide.Text = " / ";
            this.btnDivide.UseVisualStyleBackColor = false;
            this.btnDivide.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnDivide.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnDivide.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnEquals
            // 
            this.btnEquals.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnEquals.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnEquals.ForeColor = System.Drawing.Color.White;
            this.btnEquals.Location = new System.Drawing.Point(336, 349);
            this.btnEquals.Name = "btnEquals";
            this.btnEquals.Size = new System.Drawing.Size(75, 112);
            this.btnEquals.TabIndex = 19;
            this.btnEquals.Text = "=";
            this.btnEquals.UseVisualStyleBackColor = false;
            this.btnEquals.Click += new System.EventHandler(this.btnEquals_Click);
            this.btnEquals.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnEquals.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnSqrRoot
            // 
            this.btnSqrRoot.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnSqrRoot.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnSqrRoot.ForeColor = System.Drawing.Color.White;
            this.btnSqrRoot.Location = new System.Drawing.Point(336, 292);
            this.btnSqrRoot.Name = "btnSqrRoot";
            this.btnSqrRoot.Size = new System.Drawing.Size(75, 52);
            this.btnSqrRoot.TabIndex = 20;
            this.btnSqrRoot.Text = "√ ";
            this.btnSqrRoot.UseVisualStyleBackColor = false;
            this.btnSqrRoot.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnSqrRoot.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnSqrRoot.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnLog
            // 
            this.btnLog.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnLog.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnLog.ForeColor = System.Drawing.Color.White;
            this.btnLog.Location = new System.Drawing.Point(336, 120);
            this.btnLog.Name = "btnLog";
            this.btnLog.Size = new System.Drawing.Size(75, 52);
            this.btnLog.TabIndex = 21;
            this.btnLog.Text = "Log ";
            this.btnLog.UseVisualStyleBackColor = false;
            this.btnLog.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnLog.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnLog.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMsubtract
            // 
            this.btnMsubtract.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMsubtract.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnMsubtract.ForeColor = System.Drawing.Color.White;
            this.btnMsubtract.Location = new System.Drawing.Point(336, 77);
            this.btnMsubtract.Name = "btnMsubtract";
            this.btnMsubtract.Size = new System.Drawing.Size(75, 38);
            this.btnMsubtract.TabIndex = 24;
            this.btnMsubtract.Text = "M-";
            this.btnMsubtract.UseVisualStyleBackColor = false;
            this.btnMsubtract.Click += new System.EventHandler(this.btnMsubtract_Click);
            this.btnMsubtract.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMsubtract.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMplus
            // 
            this.btnMplus.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMplus.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnMplus.ForeColor = System.Drawing.Color.White;
            this.btnMplus.Location = new System.Drawing.Point(255, 77);
            this.btnMplus.Name = "btnMplus";
            this.btnMplus.Size = new System.Drawing.Size(75, 38);
            this.btnMplus.TabIndex = 25;
            this.btnMplus.Text = "M+";
            this.btnMplus.UseVisualStyleBackColor = false;
            this.btnMplus.Click += new System.EventHandler(this.btnMplus_Click);
            this.btnMplus.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMplus.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMS
            // 
            this.btnMS.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMS.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnMS.ForeColor = System.Drawing.Color.White;
            this.btnMS.Location = new System.Drawing.Point(174, 77);
            this.btnMS.Name = "btnMS";
            this.btnMS.Size = new System.Drawing.Size(75, 38);
            this.btnMS.TabIndex = 26;
            this.btnMS.Text = "MS";
            this.btnMS.UseVisualStyleBackColor = false;
            this.btnMS.Click += new System.EventHandler(this.btnMS_Click);
            this.btnMS.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMS.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMR
            // 
            this.btnMR.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMR.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnMR.ForeColor = System.Drawing.Color.White;
            this.btnMR.Location = new System.Drawing.Point(93, 77);
            this.btnMR.Name = "btnMR";
            this.btnMR.Size = new System.Drawing.Size(75, 38);
            this.btnMR.TabIndex = 27;
            this.btnMR.Text = "MR";
            this.btnMR.UseVisualStyleBackColor = false;
            this.btnMR.Click += new System.EventHandler(this.btnMR_Click);
            this.btnMR.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMR.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMC
            // 
            this.btnMC.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMC.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnMC.ForeColor = System.Drawing.Color.White;
            this.btnMC.Location = new System.Drawing.Point(12, 77);
            this.btnMC.Name = "btnMC";
            this.btnMC.Size = new System.Drawing.Size(75, 38);
            this.btnMC.TabIndex = 28;
            this.btnMC.Text = "MC";
            this.btnMC.UseVisualStyleBackColor = false;
            this.btnMC.Click += new System.EventHandler(this.btnMC_Click);
            this.btnMC.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMC.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnCloseBracket
            // 
            this.btnCloseBracket.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnCloseBracket.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnCloseBracket.ForeColor = System.Drawing.Color.White;
            this.btnCloseBracket.Location = new System.Drawing.Point(336, 177);
            this.btnCloseBracket.Name = "btnCloseBracket";
            this.btnCloseBracket.Size = new System.Drawing.Size(75, 52);
            this.btnCloseBracket.TabIndex = 29;
            this.btnCloseBracket.Text = " )";
            this.btnCloseBracket.UseVisualStyleBackColor = false;
            this.btnCloseBracket.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnCloseBracket.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnCloseBracket.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnOpenBracket
            // 
            this.btnOpenBracket.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnOpenBracket.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnOpenBracket.ForeColor = System.Drawing.Color.White;
            this.btnOpenBracket.Location = new System.Drawing.Point(255, 177);
            this.btnOpenBracket.Name = "btnOpenBracket";
            this.btnOpenBracket.Size = new System.Drawing.Size(75, 52);
            this.btnOpenBracket.TabIndex = 30;
            this.btnOpenBracket.Text = "( ";
            this.btnOpenBracket.UseVisualStyleBackColor = false;
            this.btnOpenBracket.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnOpenBracket.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnOpenBracket.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnCos
            // 
            this.btnCos.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnCos.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnCos.ForeColor = System.Drawing.Color.White;
            this.btnCos.Location = new System.Drawing.Point(93, 120);
            this.btnCos.Name = "btnCos";
            this.btnCos.Size = new System.Drawing.Size(75, 52);
            this.btnCos.TabIndex = 31;
            this.btnCos.Text = "Cos ";
            this.btnCos.UseVisualStyleBackColor = false;
            this.btnCos.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnCos.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnCos.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnSin
            // 
            this.btnSin.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnSin.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnSin.ForeColor = System.Drawing.Color.White;
            this.btnSin.Location = new System.Drawing.Point(12, 120);
            this.btnSin.Name = "btnSin";
            this.btnSin.Size = new System.Drawing.Size(75, 52);
            this.btnSin.TabIndex = 32;
            this.btnSin.Text = "Sin ";
            this.btnSin.UseVisualStyleBackColor = false;
            this.btnSin.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnSin.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnSin.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnPowerOf
            // 
            this.btnPowerOf.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnPowerOf.Font = new System.Drawing.Font("Microsoft Sans Serif", 16.2F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnPowerOf.ForeColor = System.Drawing.Color.White;
            this.btnPowerOf.Location = new System.Drawing.Point(336, 234);
            this.btnPowerOf.Name = "btnPowerOf";
            this.btnPowerOf.Size = new System.Drawing.Size(75, 52);
            this.btnPowerOf.TabIndex = 34;
            this.btnPowerOf.Text = " ^ ";
            this.btnPowerOf.UseVisualStyleBackColor = false;
            this.btnPowerOf.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnPowerOf.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnPowerOf.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnExp
            // 
            this.btnExp.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnExp.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnExp.ForeColor = System.Drawing.Color.White;
            this.btnExp.Location = new System.Drawing.Point(255, 120);
            this.btnExp.Name = "btnExp";
            this.btnExp.Size = new System.Drawing.Size(75, 52);
            this.btnExp.TabIndex = 35;
            this.btnExp.Text = "Exp ";
            this.btnExp.UseVisualStyleBackColor = false;
            this.btnExp.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnExp.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnExp.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnTan
            // 
            this.btnTan.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnTan.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btnTan.ForeColor = System.Drawing.Color.White;
            this.btnTan.Location = new System.Drawing.Point(174, 120);
            this.btnTan.Name = "btnTan";
            this.btnTan.Size = new System.Drawing.Size(75, 52);
            this.btnTan.TabIndex = 36;
            this.btnTan.Text = "Tan ";
            this.btnTan.UseVisualStyleBackColor = false;
            this.btnTan.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnTan.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnTan.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btn0
            // 
            this.btn0.BackColor = System.Drawing.Color.MidnightBlue;
            this.btn0.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.btn0.ForeColor = System.Drawing.Color.White;
            this.btn0.Location = new System.Drawing.Point(93, 408);
            this.btn0.Name = "btn0";
            this.btn0.Size = new System.Drawing.Size(75, 52);
            this.btn0.TabIndex = 37;
            this.btn0.Text = "0";
            this.btn0.UseVisualStyleBackColor = false;
            this.btn0.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btn0.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btn0.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // btnMod
            // 
            this.btnMod.BackColor = System.Drawing.Color.MidnightBlue;
            this.btnMod.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F);
            this.btnMod.ForeColor = System.Drawing.Color.White;
            this.btnMod.Location = new System.Drawing.Point(174, 409);
            this.btnMod.Name = "btnMod";
            this.btnMod.Size = new System.Drawing.Size(75, 52);
            this.btnMod.TabIndex = 38;
            this.btnMod.Text = " % ";
            this.btnMod.UseVisualStyleBackColor = false;
            this.btnMod.Click += new System.EventHandler(this.inputNumberOrOperator);
            this.btnMod.MouseDown += new System.Windows.Forms.MouseEventHandler(this.buttonPressEffect);
            this.btnMod.MouseUp += new System.Windows.Forms.MouseEventHandler(this.buttonReleaseEffect);
            // 
            // ans
            // 
            this.ans.BackColor = System.Drawing.Color.MidnightBlue;
            this.ans.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F);
            this.ans.ForeColor = System.Drawing.Color.White;
            this.ans.Location = new System.Drawing.Point(174, 178);
            this.ans.Name = "ans";
            this.ans.Size = new System.Drawing.Size(75, 52);
            this.ans.TabIndex = 39;
            this.ans.Text = "ans";
            this.ans.UseVisualStyleBackColor = false;
            this.ans.Click += new System.EventHandler(this.ans_Click);
            // 
            // frmCalculator
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 15F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.BackColor = System.Drawing.Color.Black;
            this.ClientSize = new System.Drawing.Size(423, 472);
            this.Controls.Add(this.ans);
            this.Controls.Add(this.btnMod);
            this.Controls.Add(this.btn0);
            this.Controls.Add(this.btnTan);
            this.Controls.Add(this.btnExp);
            this.Controls.Add(this.btnPowerOf);
            this.Controls.Add(this.btnSin);
            this.Controls.Add(this.btnCos);
            this.Controls.Add(this.btnOpenBracket);
            this.Controls.Add(this.btnCloseBracket);
            this.Controls.Add(this.btnMC);
            this.Controls.Add(this.btnMR);
            this.Controls.Add(this.btnMS);
            this.Controls.Add(this.btnMplus);
            this.Controls.Add(this.btnMsubtract);
            this.Controls.Add(this.btnLog);
            this.Controls.Add(this.btnSqrRoot);
            this.Controls.Add(this.btnEquals);
            this.Controls.Add(this.btnDivide);
            this.Controls.Add(this.btnMultiply);
            this.Controls.Add(this.btnSubtract);
            this.Controls.Add(this.btnPlus);
            this.Controls.Add(this.button14);
            this.Controls.Add(this.btnClear);
            this.Controls.Add(this.btnBackspace);
            this.Controls.Add(this.btn9);
            this.Controls.Add(this.btn8);
            this.Controls.Add(this.btn7);
            this.Controls.Add(this.btn6);
            this.Controls.Add(this.btn5);
            this.Controls.Add(this.btn4);
            this.Controls.Add(this.btn3);
            this.Controls.Add(this.btn2);
            this.Controls.Add(this.btn1);
            this.Controls.Add(this.txtDisplay);
            this.Name = "frmCalculator";
            this.Text = "Calculator";
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.TextBox txtDisplay;
        private System.Windows.Forms.Button btn1;
        private System.Windows.Forms.Button btn2;
        private System.Windows.Forms.Button btn3;
        private System.Windows.Forms.Button btn4;
        private System.Windows.Forms.Button btn5;
        private System.Windows.Forms.Button btn6;
        private System.Windows.Forms.Button btn7;
        private System.Windows.Forms.Button btn8;
        private System.Windows.Forms.Button btn9;
        private System.Windows.Forms.Button btnBackspace;
        private System.Windows.Forms.Button btnClear;
        private System.Windows.Forms.Button button14;
        private System.Windows.Forms.Button btnPlus;
        private System.Windows.Forms.Button btnSubtract;
        private System.Windows.Forms.Button btnMultiply;
        private System.Windows.Forms.Button btnDivide;
        private System.Windows.Forms.Button btnEquals;
        private System.Windows.Forms.Button btnSqrRoot;
        private System.Windows.Forms.Button btnLog;
        private System.Windows.Forms.Button btnMsubtract;
        private System.Windows.Forms.Button btnMplus;
        private System.Windows.Forms.Button btnMS;
        private System.Windows.Forms.Button btnMR;
        private System.Windows.Forms.Button btnMC;
        private System.Windows.Forms.Button btnCloseBracket;
        private System.Windows.Forms.Button btnOpenBracket;
        private System.Windows.Forms.Button btnCos;
        private System.Windows.Forms.Button btnSin;
        private System.Windows.Forms.Button btnPowerOf;
        private System.Windows.Forms.Button btnExp;
        private System.Windows.Forms.Button btnTan;
        private System.Windows.Forms.Button btn0;
        private System.Windows.Forms.Button btnMod;
        private System.Windows.Forms.Button ans;
    }
}

2. Calculation Functions

My scientific calculator includes standard mathematical and scientific functions, such as addition, subtraction, multiplication, division, square root, exponentiation, trigonometric functions, and more. Users can perform these calculations by clicking buttons on the interface. Results are displayed in a text box.

The code of FrmCalculator.cs:

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;
using System.Data.SqlClient;
using MySql.Data.MySqlClient;


namespace Cwk_ScientificCalculator
{
    public partial class frmCalculator : Form
    {
        MySqlConnection con;
        //This string variable is used to store the value stored and retrieved by the memory functions
        string memory = "";
        //string connectionString = "Server=localhost;Database=one;User Id=root;Password=Aa123456;";
        
        public frmCalculator()
        {
            InitializeComponent();
        }

        // Used as a shared click event for all number buttons and most operation buttons
        private void inputNumberOrOperator(object sender, EventArgs e)
        {
            if (txtDisplay.Text == "0")
                txtDisplay.Clear();

            txtDisplay.Text += ((Button)sender).Text;
        }

        // Used for pressing the '.' button
        private void inputDot(object sender, EventArgs e)
        {
            txtDisplay.Text += ((Button)sender).Text;
        }

        //Changes the button color while it is being clicked to visually show the user the button click
        private void buttonPressEffect(object sender, MouseEventArgs e)
        {
            ((Button)sender).BackColor = Color.RoyalBlue;
        }

        //Changes the button color back to the original to visually show the user that the button click has been released
        private void buttonReleaseEffect(object sender, MouseEventArgs e)
        {
            ((Button)sender).BackColor = Color.MidnightBlue;
        }

        // Clears the display and sets it to 0
        private void btnClear_Click(object sender, EventArgs e)
        {
            txtDisplay.Clear();
            txtDisplay.Text = "0";
        }

        /* Removes the last character of the display, or if there is a space,
        it will delete all spaces and the most recent number or operator*/
        private void btnBackspace_Click(object sender, EventArgs e)
        {
            for (int i = txtDisplay.Text.Length - 1; i >= 0; i--)
            {
                if (txtDisplay.Text[i] == ' ')
                {
                    txtDisplay.Text = txtDisplay.Text.Remove(i, 1);
                }
                else
                    break;
            }
            if (txtDisplay.Text.Length > 0)
                txtDisplay.Text = txtDisplay.Text.Remove(txtDisplay.Text.Length - 1, 1);

            if (txtDisplay.Text == "")
                txtDisplay.Text = "0";
        }

        // Calculates the answer of the equation contained in the display upon clicking the '=' button
        private void btnEquals_Click(object sender, EventArgs e)
        {
            string calculationString = txtDisplay.Text;
            // This breaks up the input string into individual equations by the spaces between each operator (e.g ' + ')
            List<string> equations = txtDisplay.Text.Split(' ').ToList();
            string connStr = "server=127.0.0.1;port=3306;user=root;password=Aa123456;database=calculator;";
            con = new MySqlConnection(connStr);
            try
            {
                //First calculates any equations between brackets
                List<string> newEquations = calculateBrackets(equations);
                //Once the bracket equations have been evaluated, uses theh calculate method to calculate the final answer
                txtDisplay.Text = calculate(newEquations);

                con.Open();
                string result = txtDisplay.Text;

                // Save the calculation and result to the database
                string query = "INSERT INTO CalculationHistory (CalculationString, Result) VALUES (@CalculationString, @Result)";
                using (MySqlCommand cmd = new MySqlCommand(query, con))
                {
                    cmd.Parameters.AddWithValue("@CalculationString", calculationString);
                    cmd.Parameters.AddWithValue("@Result", result);
                    cmd.ExecuteNonQuery();
                }
            }
            catch (Exception exc)
            {
                txtDisplay.Text = "ERROR - Invalid Input";
            }
            
        }

        private List<string> calculateBrackets(List<string> equations)
        {

            for (int i = 0; i < equations.Count; i++)
            {
                //Searches for the first open bracket
                if (equations[i].Equals("("))
                {
                    for (int j = i; j < equations.Count; j++)
                    {
                        //Searches for the first closed bracket after the located open bracket
                        if (equations[j].Equals(")"))
                        {
                            //Creates a list of strings for containing the equations between the open and closed bracket
                            List<string> bracketEquations = new List<string>();

                            for (int k = i + 1; k < j; k++)
                            {
                                bracketEquations.Add(equations[k]);
                            }
                            //Calls the calculate method for the equations located between the brackets
                            string bracketAnswer = calculate(bracketEquations);
                            equations[i] = bracketAnswer;
                            for (int l = j; l > i; l--)
                            {
                                equations.RemoveAt(l);
                            }
                            break;
                        }
                    }
                }
            }
            return equations;
        }

        // Used to calculate the answer from the txtDisplay input
        private string calculate(List<string> equations)
        {

            //Sin Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("Sin"))
                {
                    int rightValue = i + 1;
                    double result = Math.Sin(double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                }
            }

            //Cos Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("Cos"))
                {
                    int rightValue = i + 1;
                    double result = Math.Cos(double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                }
            }

            //Tan Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("Tan"))
                {
                    int rightValue = i + 1;
                    double result = Math.Tan(double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                }
            }

            //Exponent Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("Exp"))
                {
                    int rightValue = i + 1;
                    double result = Math.Exp(double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                }
            }

            //Logarithm Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("Log"))
                {
                    int rightValue = i + 1;
                    double result = Math.Log(double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                }
            }

            //PowerOf Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("^"))
                {
                    int leftValue = i - 1;
                    int rightValue = i + 1;
                    double result = Math.Pow(double.Parse(equations[leftValue]), double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                    equations.RemoveAt(leftValue);
                    i--;
                }
            }

            //Square Root Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("√"))
                {
                    int rightValue = i + 1;
                    double result = Math.Sqrt(double.Parse(equations[rightValue]));

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                }
            }

            //Multiplication Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("*"))
                {
                    int leftValue = i - 1;
                    int rightValue = i + 1;
                    double result = double.Parse(equations[leftValue]) * double.Parse(equations[rightValue]);

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                    equations.RemoveAt(leftValue);
                    i--;
                }
            }

            //Division Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("/"))
                {
                    int leftValue = i - 1;
                    int rightValue = i + 1;
                    double result = double.Parse(equations[leftValue]) / double.Parse(equations[rightValue]);

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                    equations.RemoveAt(leftValue);
                    i--;
                }
            }

            //Mod Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("%"))
                {
                    int leftValue = i - 1;
                    int rightValue = i + 1;
                    double result = double.Parse(equations[leftValue]) - (int)(double.Parse(equations[leftValue]) / double.Parse(equations[rightValue])) * double.Parse(equations[rightValue]);
                    
                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                    equations.RemoveAt(leftValue);
                    i--;
                }
            }

            //Subtraction Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("-"))
                {
                    int leftValue = i - 1;
                    int rightValue = i + 1;
                    double result = double.Parse(equations[leftValue]) - double.Parse(equations[rightValue]);

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                    equations.RemoveAt(leftValue);
                    i--;
                }
            }

            //Addition Operation
            for (int i = 0; i < equations.Count; i++)
            {
                if (equations[i].Equals("+"))
                {
                    int leftValue = i - 1;
                    int rightValue = i + 1;
                    double result = double.Parse(equations[leftValue]) + double.Parse(equations[rightValue]);

                    equations[i] = result.ToString();
                    equations.RemoveAt(rightValue);
                    equations.RemoveAt(leftValue);
                    i--;
                }
            }

           
            return equations[0];
        }

        private void btnMS_Click(object sender, EventArgs e)
        {
            List<string> equations = txtDisplay.Text.Split(' ').ToList();
            memory = calculate(equations);
        }

        private void btnMR_Click(object sender, EventArgs e)
        {
            if (txtDisplay.Text == "0")
                txtDisplay.Clear();

            txtDisplay.Text += memory.ToString();

            if (txtDisplay.Text == "")
                txtDisplay.Text = "0";
        }

        private void btnMC_Click(object sender, EventArgs e)
        {
            memory = "";
        }

        private void btnMplus_Click(object sender, EventArgs e)
        {
            List<string> equations = txtDisplay.Text.Split(' ').ToList();
            memory = (double.Parse(memory) + double.Parse(calculate(equations))).ToString();
        }

        private void btnMsubtract_Click(object sender, EventArgs e)
        {
            List<string> equations = txtDisplay.Text.Split(' ').ToList();
            memory = (double.Parse(memory) - double.Parse(calculate(equations))).ToString();
        }

        private void ans_Click(object sender, EventArgs e)
        {

            string connStr = "server=127.0.0.1;port=3306;user=root;password=Aa123456;database=calculator;";
            con = new MySqlConnection(connStr);
           
            try
            {
                
                con.Open();
                string history = "";
                string query = "SELECT CalculationString, Result FROM CalculationHistory ORDER BY ID DESC LIMIT 10";
                using (MySqlCommand cmd = new MySqlCommand(query, con))
                {
                    using (MySqlDataReader reader = cmd.ExecuteReader())
                    {
                        
                        while (reader.Read() )
                        {
                            string calculationString = reader.GetString("CalculationString");
                            string result = reader.GetString("Result");
                            history = history+calculationString + " = " + result + "\r\n";
                            
                        }
                    }
                }
                MessageBox.Show(history,"History");
                
                con.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
     }
}

3. History Records

To implement the history records feature, I set up a MySQL database to store users' calculation history. Each time a user performs a new calculation, the expressio and result are recorded in the database. This enables users to retrieve previous calculation records at any time.

V. Interaction with the MySQL Database

To interact with the MySQL database, I used the MySQL Connector library. This allowed me to establish a connection to the database, execute SQL queries, and update the history records table. Here are the main steps I followed for interacting with the database:

1. Create MySQL Database

I create a table named "CalculationHistory" with columns for the calculation string and its result.

CREATE TABLE CalculationHistory (
    ID INT AUTO_INCREMENT PRIMARY KEY,
    CalculationString VARCHAR(255),
    Result VARCHAR(255)
);

2. Connecting to the Database

• To import the mysql database reference, in Explorer, right-click on the project and select Nuget Package

• Search for mysql and install

• Importing references to mysql and defining global variables

using MySql.Data.MySqlClient;
MySqlConnection con;

I established a connection to the MySQL database when the application was launched. I used a connection string to specify the database's location, username, and password.

string connStr = "server=127.0.0.1;port=3306;user=root;password=Aa123456;database=calculator;";
con = new MySqlConnection(connStr);

3. Inserting History Records

Whenever a user performed a calculation, I created an INSERT query to insert the calculation expression and result into the history records table.

try
{
    //First calculates any equations between brackets
    List<string> newEquations = calculateBrackets(equations);
    //Once the bracket equations have been evaluated, uses theh calculate method to calculate the final answer
    txtDisplay.Text = calculate(newEquations);

    con.Open();
    string result = txtDisplay.Text;

    // Save the calculation and result to the database
    string query = "INSERT INTO CalculationHistory (CalculationString, Result) VALUES (@CalculationString, @Result)";
    using (MySqlCommand cmd = new MySqlCommand(query, con))
    {
        cmd.Parameters.AddWithValue("@CalculationString", calculationString);
        cmd.Parameters.AddWithValue("@Result", result);
        cmd.ExecuteNonQuery();
    }
}
catch (Exception exc)
{
    txtDisplay.Text = "ERROR - Invalid Input";
}

4. Retrieving History Records

When a user wanted to view their history records, I executed a SELECT query to retrieve the ten most recent entries and displayed them in the application's history
panel.

 private void ans_Click(object sender, EventArgs e)
 {

     string connStr = "server=127.0.0.1;port=3306;user=root;password=Aa123456;database=calculator;";
     con = new MySqlConnection(connStr);
    
     try
     {
         
         con.Open();
         string history = "";
         string query = "SELECT CalculationString, Result FROM CalculationHistory ORDER BY ID DESC LIMIT 10";
         using (MySqlCommand cmd = new MySqlCommand(query, con))
         {
             using (MySqlDataReader reader = cmd.ExecuteReader())
             {
                 
                 while (reader.Read() )
                 {
                     string calculationString = reader.GetString("CalculationString");
                     string result = reader.GetString("Result");
                     history = history+calculationString + " = " + result + "\r\n";
                     
                 }
             }
         }
         MessageBox.Show(history,"History");
         
         con.Close();
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }

VI. Flow Chart

VII. Additional Features

Bracket Calculation Function: The calculator can handle mathematical expressions enclosed in brackets, perform calculations within the brackets, and return the results. This can be used for complex expressions and equations.

Trigonometric and Other Mathematical Functions: The calculator supports trigonometric functions (sin, cos, tan), exponential functions (exp), logarithmic functions (log), and more. You can input these functions in the input field, and the calculator will execute the corresponding mathematical operations.

Memory Function: The calculator has a memory function, including storage(MS), retrieval(MR), clearing of memory(MC), and addition(M+) and subtraction(M-) operations in memory. This allows you to store intermediate results during calculations and retrieve or modify them when needed.

VIII. Summary

By adopting a front-end and back-end separation approach, I successfully developed a powerful scientific calculator with a database. This approach not only enhances development but also lays a foundation for scaling the application and making future improvements.This project provided me with valuable insights into WinForms interface design and MySQL database operations, enhancing my development skills.