将下面代码改成C#窗体 using System;using System.Numerics;// 生成公钥和私钥BigInteger p = BigInteger.Parse("857504083339712752489993810777");BigInteger q = BigInteger.Parse("1029224947942998075080348647219");BigInteger n = p * q;BigInteger phi = (p - 1) * (q - 1);BigInteger e = 65537;BigInteger d = ModInverse(e, phi);// 加密数据BigInteger message = BigInteger.Parse("123456789");BigInteger encrypted = ModPow(message, e, n);// 解密数据BigInteger decrypted = ModPow(encrypted, d, n);Console.WriteLine("原始数据：{0}", message);Console.WriteLine("加密后数据：{0}", encrypted);Console.WriteLine("解密后数据：{0}", decrypted);// 求模反元素public static BigInteger ModInverse(BigInteger a, BigInteger m){ BigInteger m0 = m; BigInteger y = 0, x = 1; if (m == 1) return 0; while (a > 1) { BigInteger q = a / m; BigInteger t = m; m = a % m; a = t; t = y; y = x - q * y; x = t; } if (x < 0) x += m0; return x;}// 模幂运算public static BigInteger ModPow(BigInteger b, BigInteger e, BigInteger m){ BigInteger result = 1; while (e > 0) { if ((e & 1) == 1) result = (result * b) % m; e >>= 1; b = (b * b) % m; } return result;}

以下是将代码改写成C#窗体的示例：

using System;
using System.Numerics;
using System.Windows.Forms;

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

        private void btnEncrypt_Click(object sender, EventArgs e)
        {
            // 生成公钥和私钥
            BigInteger p = BigInteger.Parse("857504083339712752489993810777");
            BigInteger q = BigInteger.Parse("1029224947942998075080348647219");
            BigInteger n = p * q;
            BigInteger phi = (p - 1) * (q - 1);
            BigInteger e = 65537;
            BigInteger d = ModInverse(e, phi);

            // 加密数据
            BigInteger message = BigInteger.Parse(txtData.Text);
            BigInteger encrypted = ModPow(message, e, n);

            // 解密数据
            BigInteger decrypted = ModPow(encrypted, d, n);

            // 显示结果
            txtEncrypted.Text = encrypted.ToString();
            txtDecrypted.Text = decrypted.ToString();
        }

        // 求模反元素
        public static BigInteger ModInverse(BigInteger a, BigInteger m)
        {
            BigInteger m0 = m;
            BigInteger y = 0, x = 1;

            if (m == 1)
                return 0;

            while (a > 1)
            {
                BigInteger q = a / m;
                BigInteger t = m;

                m = a % m;
                a = t;
                t = y;

                y = x - q * y;
                x = t;
            }

            if (x < 0)
                x += m0;

            return x;
        }

        // 模幂运算
        public static BigInteger ModPow(BigInteger b, BigInteger e, BigInteger m)
        {
            BigInteger result = 1;

            while (e > 0)
            {
                if ((e & 1) == 1)
                    result = (result * b) % m;

                e >>= 1;
                b = (b * b) % m;
            }

            return result;
        }
    }
}

在这个示例中，我们在窗体中添加了三个文本框(txtData、txtEncrypted和txtDecrypted)和一个按钮(btnEncrypt)。当用户输入要加密的数据后，点击按钮即可进行加密和解密，并将结果显示在相应的文本框中。