---

1. 前端界面

<Window x:Class="Cal.MainWindow"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:local="clr-namespace:Cal"mc:Ignorable="d"Title="科學計算器" Height="600" Width="400"WindowStartupLocation="CenterScreen"ResizeMode="NoResize"><Window.Resources><Style TargetType="Button"><Setter Property="FontSize" Value="20"/><Setter Property="Margin" Value="5"/><Setter Property="Background" Value="#FF333333"/><Setter Property="Foreground" Value="White"/><Setter Property="BorderThickness" Value="0"/><Setter Property="BorderBrush" Value="#FF555555"/></Style></Window.Resources><Grid Background="#FF222222"><Grid.RowDefinitions><RowDefinition Height="Auto"/><RowDefinition Height="*"/></Grid.RowDefinitions><!-- 顯示區域 --><Border Grid.Row="0" Background="#FF111111" Padding="10,10,10,10" Margin="10,10,10,10"><StackPanel><TextBlock x:Name="txtHistory" Foreground="#FFAAAAAA" FontSize="16" HorizontalAlignment="Right" Margin="0,0,0,5"/><TextBlock x:Name="txtDisplay" Foreground="White" FontSize="36" HorizontalAlignment="Right" Text="0"/></StackPanel></Border><!-- 按鈕區域 --><Grid Grid.Row="1" Margin="10"><Grid.RowDefinitions><RowDefinition Height="*"/><RowDefinition Height="*"/><RowDefinition Height="*"/><RowDefinition Height="*"/><RowDefinition Height="*"/><RowDefinition Height="*"/></Grid.RowDefinitions><Grid.ColumnDefinitions><ColumnDefinition Width="*"/><ColumnDefinition Width="*"/><ColumnDefinition Width="*"/><ColumnDefinition Width="*"/><ColumnDefinition Width="*"/></Grid.ColumnDefinitions><!-- 第二行 --><Button x:Name="btnClear" Grid.Row="1" Grid.Column="0" Content="C" Background="#FFAA0000"/><Button x:Name="btnBack" Grid.Row="1" Grid.Column="1" Content="?"/><Button x:Name="btnPercent" Grid.Row="1" Grid.Column="2" Content="%"/><Button x:Name="btnDivide" Grid.Row="1" Grid.Column="3" Content="/" Background="#FF555555"/><Button x:Name="btnSqrt" Grid.Row="1" Grid.Column="4" Content="√" Background="#FF555555"/><!-- 第一行 --><Button x:Name="btnTan" Grid.Row="0" Grid.Column="0" Content="tan" Background="#FF555555"/><Button x:Name="btnLog" Grid.Row="0" Grid.Column="1" Content="log" Background="#FF555555"/><Button x:Name="btnLn" Grid.Row="0" Grid.Column="2" Content="ln" Background="#FF555555"/><Button x:Name="btnPi" Grid.Row="0" Grid.Column="3" Content="π" Background="#FF555555"/><Button x:Name="btnFactorial" Grid.Row="0" Grid.Column="4" Content="n!" Background="#FF555555"/><!-- 第三行 --><Button x:Name="btn7" Grid.Row="2" Grid.Column="0" Content="7" /><Button x:Name="btn8" Grid.Row="2" Grid.Column="1" Content="8"/><Button x:Name="btn9" Grid.Row="2" Grid.Column="2" Content="9"/><Button x:Name="btnMultiply" Grid.Row="2" Grid.Column="3" Content="×" Background="#FF555555"/><Button x:Name="btnPower" Grid.Row="2" Grid.Column="4" Content="x^y" Background="#FF555555"/><!-- 第四行 --><Button x:Name="btn4" Grid.Row="3" Grid.Column="0" Content="4"/><Button x:Name="btn5" Grid.Row="3" Grid.Column="1" Content="5"/><Button x:Name="btn6" Grid.Row="3" Grid.Column="2" Content="6"/><Button x:Name="btnSubtract" Grid.Row="3" Grid.Column="3" Content="-" Background="#FF555555"/><Button x:Name="btnSin" Grid.Row="3" Grid.Column="4" Content="sin" Background="#FF555555"/><!-- 第五行 --><Button x:Name="btn1" Grid.Row="4" Grid.Column="0" Content="1"/><Button x:Name="btn2" Grid.Row="4" Grid.Column="1" Content="2"/><Button x:Name="btn3" Grid.Row="4" Grid.Column="2" Content="3"/><Button x:Name="btnAdd" Grid.Row="4" Grid.Column="3" Content="+" Background="#FF555555"/><Button x:Name="btnCos" Grid.Row="4" Grid.Column="4" Content="cos" Background="#FF555555"/><!-- 第六行 --><Button x:Name="btn0" Grid.Row="5" Grid.Column="0" Content="0"/><Button x:Name="btnDecimal" Grid.Row="5" Grid.Column="1" Content="."/><Button x:Name="btnPlusMinus" Grid.Row="5" Grid.Column="2" Content="±"/><Button x:Name="btnEquals" Grid.Row="5" Grid.Column="3" Grid.ColumnSpan="2" Content="=" Background="#FF007ACC"/></Grid></Grid>
</Window>

2. 功能代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;namespace Cal
{/// <summary>/// MainWindow.xaml 的交互邏輯/// </summary>public partial class MainWindow : Window{private string currentInput = "0";//當前輸入private string previousInput = "";//之前輸入private string operation = "";//操作符private bool newInput = true;private bool operationPerformed = false;//操作已執行public MainWindow(){InitializeComponent();// 數字按鈕事件btn0.Click += NumberButton_Click;btn1.Click += NumberButton_Click;btn2.Click += NumberButton_Click;btn3.Click += NumberButton_Click;btn4.Click += NumberButton_Click;btn5.Click += NumberButton_Click;btn6.Click += NumberButton_Click;btn7.Click += NumberButton_Click;btn8.Click += NumberButton_Click;btn9.Click += NumberButton_Click;// 運算符按鈕事件btnAdd.Click += OperatorButton_Click;btnSubtract.Click += OperatorButton_Click;btnMultiply.Click += OperatorButton_Click;btnDivide.Click += OperatorButton_Click;btnEquals.Click += EqualsButton_Click;// 功能按鈕事件btnClear.Click += ClearButton_Click;btnBack.Click += BackButton_Click;btnDecimal.Click += DecimalButton_Click;btnPlusMinus.Click += PlusMinusButton_Click;btnPercent.Click += PercentButton_Click;// 科學計算按鈕事件btnSqrt.Click += ScientificButton_Click;btnPower.Click += ScientificButton_Click;btnSin.Click += ScientificButton_Click;btnCos.Click += ScientificButton_Click;btnTan.Click += ScientificButton_Click;btnLog.Click += ScientificButton_Click;btnLn.Click += ScientificButton_Click;btnPi.Click += ScientificButton_Click;btnFactorial.Click += ScientificButton_Click;}private void NumberButton_Click(object sender, RoutedEventArgs e){Button button = (Button)sender;if (currentInput == "0" || newInput){currentInput = button.Content.ToString();newInput = false;}else{currentInput += button.Content.ToString();}UpdateDisplay();}private void OperatorButton_Click(object sender, RoutedEventArgs e){Button button = (Button)sender;if (!newInput && !operationPerformed){Calculate();}operation = button.Content.ToString();previousInput = currentInput;newInput = true;operationPerformed = false;UpdateHistory();}private void EqualsButton_Click(object sender, RoutedEventArgs e){Calculate();operation = "";UpdateHistory();newInput = true;operationPerformed = true;}private void Calculate(){if (string.IsNullOrEmpty(previousInput) || string.IsNullOrEmpty(operation))return;double num1 = double.Parse(previousInput);double num2 = double.Parse(currentInput);double result = 0;switch (operation){case "+":result = num1 + num2;break;case "-":result = num1 - num2;break;case "×":result = num1 * num2;break;case "/":result = num1 / num2;break;}currentInput = result.ToString();UpdateDisplay();}private void ScientificButton_Click(object sender, RoutedEventArgs e){Button button = (Button)sender;double num = double.Parse(currentInput);double result = 0;switch (button.Content.ToString()){case "√":result = Math.Sqrt(num);break;case "x^y":// 需要額外處理冪運算previousInput = currentInput;operation = "^";newInput = true;UpdateHistory();return;case "sin":result = Math.Sin(num * Math.PI / 180); // 轉換為弧度break;case "cos":result = Math.Cos(num * Math.PI / 180);break;case "tan":result = Math.Tan(num * Math.PI / 180);break;case "log":result = Math.Log10(num);break;case "ln":result = Math.Log(num);break;case "π":currentInput = Math.PI.ToString();UpdateDisplay();return;case "n!":result = Factorial((int)num);break;}currentInput = result.ToString();UpdateDisplay();newInput = true;}private int Factorial(int n){if (n <= 1)return 1;return n * Factorial(n - 1);}private void ClearButton_Click(object sender, RoutedEventArgs e){currentInput = "0";previousInput = "";operation = "";newInput = true;UpdateDisplay();txtHistory.Text = "";}private void BackButton_Click(object sender, RoutedEventArgs e){if (currentInput.Length > 1){currentInput = currentInput.Substring(0, currentInput.Length - 1);}else{currentInput = "0";newInput = true;}UpdateDisplay();}private void DecimalButton_Click(object sender, RoutedEventArgs e){if (!currentInput.Contains(".")){currentInput += ".";UpdateDisplay();}}private void PlusMinusButton_Click(object sender, RoutedEventArgs e){if (currentInput != "0"){if (currentInput.StartsWith("-")){currentInput = currentInput.Substring(1);}else{currentInput = "-" + currentInput;}UpdateDisplay();}}private void PercentButton_Click(object sender, RoutedEventArgs e){double num = double.Parse(currentInput);currentInput = (num / 100).ToString();UpdateDisplay();}private void UpdateDisplay(){txtDisplay.Text = currentInput;}private void UpdateHistory(){//$為字符串拼接的優化，等同于string.Format（），示例如下：txtHistory.Text = $"{previousInput} {operation}";}}
}

3. 效果展示