winform UI 包含计算器的

以下是一个简单的计算器 WinForm UI 的示例，包含加减乘除四个基本运算：

using System;
using System.Windows.Forms;

namespace CalculatorApp
{
    public partial class Form1 : Form
    {
        double num1, num2, result;
        char op;

        public Form1()
        {
            InitializeComponent();
        }

        private void btn0_Click(object sender, EventArgs e)
        {
            txtResult.Text += "0";
        }

        private void btn1_Click(object sender, EventArgs e)
        {
            txtResult.Text += "1";
        }

        private void btn2_Click(object sender, EventArgs e)
        {
            txtResult.Text += "2";
        }

        private void btn3_Click(object sender, EventArgs e)
        {
            txtResult.Text += "3";
        }

        private void btn4_Click(object sender, EventArgs e)
        {
            txtResult.Text += "4";
        }

        private void btn5_Click(object sender, EventArgs e)
        {
            txtResult.Text += "5";
        }

        private void btn6_Click(object sender, EventArgs e)
        {
            txtResult.Text += "6";
        }

        private void btn7_Click(object sender, EventArgs e)
        {
            txtResult.Text += "7";
        }

        private void btn8_Click(object sender, EventArgs e)
        {
            txtResult.Text += "8";
        }

        private void btn9_Click(object sender, EventArgs e)
        {
            txtResult.Text += "9";
        }

        private void btnPlus_Click(object sender, EventArgs e)
        {
            num1 = Convert.ToDouble(txtResult.Text);
            op = '+';
            txtResult.Text = "";
        }

        private void btnMinus_Click(object sender, EventArgs e)
        {
            num1 = Convert.ToDouble(txtResult.Text);
            op = '-';
            txtResult.Text = "";
        }

        private void btnMultiply_Click(object sender, EventArgs e)
        {
            num1 = Convert.ToDouble(txtResult.Text);
            op = '*';
            txtResult.Text = "";
        }

        private void btnDivide_Click(object sender, EventArgs e)
        {
            num1 = Convert.ToDouble(txtResult.Text);
            op = '/';
            txtResult.Text = "";
        }

        private void btnEquals_Click(object sender, EventArgs e)
        {
            num2 = Convert.ToDouble(txtResult.Text);

            switch (op)
            {
                case '+':
                    result = num1 + num2;
                    break;
                case '-':
                    result = num1 - num2;
                    break;
                case '*':
                    result = num1 * num2;
                    break;
                case '/':
                    result = num1 / num2;
                    break;
            }

            txtResult.Text = result.ToString();
        }

        private void btnClear_Click(object sender, EventArgs e)
        {
            txtResult.Text = "";
        }

        private void btnDot_Click(object sender, EventArgs e)
        {
            if (!txtResult.Text.Contains("."))
            {
                txtResult.Text += ".";
            }
        }

        private void btnSign_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(txtResult.Text))
            {
                double value = Convert.ToDouble(txtResult.Text);
                value = -value;
                txtResult.Text = value.ToString();
            }
        }
    }
}

其中，`Form1` 是主窗体，包含按钮和文本框等控件。每个数字按钮的 `Click` 事件都将相应数字添加到文本框中。四个基本运算的按钮分别设置了 `num1` 和 `op` 变量，以便进行后续计算。等于号按钮 `Click` 事件中，根据当前运算符进行对应的计算，并将结果显示在文本框中。清除按钮将文本框清空。小数点按钮添加小数点到文本框中。正负号按钮将当前值取反。