本文所述实例为使用伪随机数进行用户密码加密，这段代码为核心部分主要代码，需要配合其它的程序实现，感兴趣的读者可以自己进一步加以完善，不费话了，下面列出主要代码：

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 PRanDataEncrypt { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { if (textBox3.Text != "") { if (DecryptPwd(textBox3.Text) == textBox2.Text) MessageBox.Show("用户登录成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); else MessageBox.Show("用户密码错误！", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error); } } private void button2_Click(object sender, EventArgs e) { textBox1.Text = textBox2.Text = textBox3.Text = string.Empty; textBox2.Focus(); } private void textBox2_TextChanged(object sender, EventArgs e) { textBox3.Text = EncryptPwd(textBox2.Text); } //定义加密用户密码所用的伪随机数 private string randStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz"; #region 使用伪随机数加密用户登录密码 /// <summary> /// 使用伪随机数加密用户登录密码 /// </summary> /// <param name="str">用户登录密码</param> /// <returns>加密后的用户登录密码</returns> private string EncryptPwd(string str) { byte[] btData = Encoding.Default.GetBytes(str); int j, k, m; int len = randStr.Length; StringBuilder sb = new StringBuilder(); Random rand = new Random(); for (int i = 0; i < btData.Length; i++) { j = (byte)rand.Next(6); btData[i] = (byte)((int)btData[i] ^ j); k = (int)btData[i] % len; m = (int)btData[i] / len; m = m * 8 + j; sb.Append(randStr.Substring(k, 1) + randStr.Substring(m, 1)); } return sb.ToString(); } #endregion #region 解密用户登录密码 /// <summary> /// 解密用户登录密码 /// </summary> /// <param name="str">经过加密的用户登录密码</param> /// <returns>解密后的用户登录密码</returns> private string DecryptPwd(string str) { try { int j, k, m, n = 0; int len = randStr.Length; byte[] btData = new byte[str.Length / 2]; for (int i = 0; i < str.Length; i += 2) { k = randStr.IndexOf(str[i]); m = randStr.IndexOf(str[i + 1]); j = m / 8; m = m - j * 8; btData[n] = (byte)(j * len + k); btData[n] = (byte)((int)btData[n] ^ m); n++; } return Encoding.Default.GetString(btData); } catch { return ""; } } #endregion } }