用C#窗体编写能加减乘除的计算器有0-9和加减乘除按钮

以下是使用C#窗体编写的简单加减乘除计算器的示例代码：

using System;
using System.Windows.Forms;

namespace CalculatorApp
{
    public partial class CalculatorForm : Form
    {
        private double firstNumber;
        private double secondNumber;
        private string operation;

        public CalculatorForm()
        {
            InitializeComponent();
        }

        private void NumericButton_Click(object sender, EventArgs e)
        {
            Button button = (Button)sender;
            InputTextBox.Text += button.Text;
        }

        private void OperatorButton_Click(object sender, EventArgs e)
        {
            Button button = (Button)sender;
            operation = button.Text;
            firstNumber = double.Parse(InputTextBox.Text);
            InputTextBox.Text = "";
        }

        private void EqualsButton_Click(object sender, EventArgs e)
        {
            secondNumber = double.Parse(InputTextBox.Text);
            double result = CalculateResult();
            InputTextBox.Text = result.ToString();
        }

        private double CalculateResult()
        {
            double result = 0;
            switch (operation)
            {
                case "+":
                    result = firstNumber + secondNumber;
                    break;
                case "-":
                    result = firstNumber - secondNumber;
                    break;
                case "*":
                    result = firstNumber * secondNumber;
                    break;
                case "/":
                    if (secondNumber != 0)
                    {
                        result = firstNumber / secondNumber;
                    }
                    else
                    {
                        MessageBox.Show("Cannot divide by zero", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                    break;
            }
            return result;
        }
    }
}

在窗体设计器中，将以下控件拖放到窗体上：

• 一个TextBox控件，命名为InputTextBox，用于显示用户输入和计算结果。
• 十个Button控件，命名为NumericButton0到NumericButton9，用于输入数字0到9。
• 四个Button控件，命名为OperatorButtonAdd、OperatorButtonSubtract、OperatorButtonMultiply和OperatorButtonDivide，用于选择加法、减法、乘法和除法操作。
• 一个Button控件，命名为EqualsButton，用于执行计算。