小賴的實戰記錄

這是我改寫別人程式後程式碼

//*****************************************************************************//
//功能：產生亂數密碼                                                           //
//*****************************************************************************//
using System;
using System.Security.Cryptography;
using System.Text ;
/// <summary>
/// 使用 RNGCryptoServiceProvider 產生由密碼編譯服務供應者 (CSP) 提供的亂數產生器。
/// </summary>
public class RandomPassword
{
    private RNGCryptoServiceProvider rngp = new RNGCryptoServiceProvider();
    private byte[] rb = new byte[4];

    /// <summary>
    /// 產生一個非負數的亂數
    /// </summary>
    private int Next()
    {
        rngp.GetBytes(rb);
        int value = BitConverter.ToInt32(rb, 0);
        if (value < 0) value = -value;
        return value;
    }
    /// <summary>
    /// 產生一個非負數且最大值 max 以下的亂數
    /// </summary>
    /// <param name="max">最大值</param>
    private int Next(int max)
    {
        rngp.GetBytes(rb);
        int value = BitConverter.ToInt32(rb, 0);
        value = value % (max + 1);
        if (value < 0) value = -value;
        return value;
    }
    /// <summary>
    /// 產生一個非負數且最小值在 min 以上最大值在 max 以下的亂數
    /// </summary>
    /// <param name="min">最小值</param>
    /// <param name="max">最大值</param>
    private int Next(int min, int max)
    {
        int value = Next(max - min) + min;
        return value;
    }

    public string GetRandomPassword(int length)
    {
        StringBuilder sb = new StringBuilder();
        char[] chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();

        for (int i = 0; i < length; i++)
        {
            sb.Append(chars[this.Next(chars.Length - 1)]);
        }
        string Password = sb.ToString();
        return Password;
    }
}