藍天。玄舍。這起航的旅程

很不錯的C#教學網站

目的 : 簡易型計算機

軟體 : Microsoft Visual C# 2008 Express Edition  

專案 : Windows Form

Code :

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace TestCalculator
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                double number1 = double.Parse(textBox1.Text);    // Parse 為強制轉型
                double number2 = double.Parse(textBox2.Text);
                string op = comboBox1.Text;
                double result = 0;
                switch (op)
                {

                    // 在 C# 裡必須在 case 中加上 break
                    case "+": result = number1 + number2; break;   
                    case "-": result = number1 - number2; break;
                    case "*": result = number1 * number2; break;
                    case "/": result = number1 / number2; break;
                    default: throw new Exception("op = " + op + " Error!");
                }
                textBox3.Text = result.ToString();
            }
            catch ( Exception exception )    // 例外處理
            {
                MessageBox.Show( exception.ToString());
            }
        }
    }
}

執行結果 :　

工具箱 :

Button --- Text , Name , TabIndex

ComboBox --- Text , Items , TabIndex

TextBox --- Text , Name , TabIndex

Label --- Text