apewer-dotnet/Apewer/Internals/RandomHelper.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace Apewer.Internals
{

    internal class RandomHelper
    {

        /// <summary>生成新的 GUID。</summary>
        public static string NewGuid(bool argHyphenation = false, bool argLowerCase = true)
        {
            var vguid = System.Guid.NewGuid().ToString();
            if (argLowerCase) vguid = vguid.ToLower();
            else vguid = vguid.ToUpper();
            if (!argHyphenation) vguid = vguid.Replace("-", "");
            return vguid;
        }

        /// <summary>用于生成随机数的时钟。</summary>
        private static float RandomTimer()
        {
            var now = DateTime.Now;
            return (float)((double)(checked((60 * now.Hour + now.Minute) * 60 + now.Second)) + (double)now.Millisecond / 1000.0);
        }

        /// <summary>用于生成随机数的时钟位置。</summary>
        private static int RandomSeed = 327680;

        /// <summary>初始化随机数生成。</summary>
        private static void Randomize()
        {
            RandomInit();
        }

        /// <summary>初始化随机数生成。</summary>
        public static void RandomInit()
        {
            float vtimer = RandomTimer();
            int vnum1 = RandomSeed;
            int vnum2 = BitConverter.ToInt32(BitConverter.GetBytes(vtimer), 0);
            vnum2 = ((vnum2 & 65535) ^ vnum2 >> 16) << 8;
            vnum1 = ((vnum1 & -16776961) | vnum2);
            RandomSeed = vnum1;
        }

        /// <summary>初始化随机数生成。</summary>
        public static void RandomInit(double argNumber)
        {
            int vnum1 = RandomSeed;
            int vnum2 = BitConverter.ToInt32(BitConverter.GetBytes(argNumber), (BitConverter.IsLittleEndian ? 4 : 8));
            vnum2 = ((vnum2 & 65535) ^ vnum2 >> 16) << 8;
            vnum1 = ((vnum1 & -16776961) | vnum2);
            RandomSeed = vnum1;
        }

        /// <summary>生成一个不大于 1 的随机单精度浮点数，最小为 0。</summary>
        public static float RandomFloat()
        {
            return RandomFloat(1f);
        }

        /// <summary>生成一个随机单精度浮点数。</summary>
        public static float RandomFloat(float argNumber)
        {
            int vnum1 = RandomSeed;
            if ((double)argNumber != 0.0)
            {
                if ((double)argNumber < 0.0)
                {
                    vnum1 = BitConverter.ToInt32(BitConverter.GetBytes(argNumber), 0);
                    long vnum2 = (long)vnum1;
                    vnum2 &= unchecked((long)((ulong)-1));
                    vnum1 = checked((int)(vnum2 + (vnum2 >> 24) & 16777215L));
                }
                vnum1 = checked((int)(unchecked((long)vnum1) * 1140671485L + 12820163L & 16777215L));
            }
            RandomSeed = vnum1;
            return (float)vnum1 / 16777216f;
        }

        /// <summary>生成随机整数，最小为 0。</summary>
        /// <param name="argMax">最大数。</param>
        /// <returns></returns>
        public static int RandomInteger(int argMax)
        {
            return RandomInteger(0, argMax);
        }

        /// <summary>生成随机整数。</summary>
        /// <param name="argMin">最小数。</param>
        /// <param name="argMax">最大数。</param>
        /// <returns></returns>
        public static int RandomInteger(int argMin, int argMax)
        {
            RandomInit();
            float vfloat = (argMax - argMin + 1) * RandomFloat();
            int vint = argMin + (int)vfloat;
            return vint;
        }

        /// <summary>由指定字符成的随机字符串。</summary>
        /// <param name="argPool">字符池，字符池中每个字符在随机字符串中出现的概率约等。</param>
        /// <param name="argLength">随机字符串的长度。</param>
        public static string RandomCustom(string argPool, int argLength)
        {
            switch (TextHelper.Len(argPool))
            {
                case 0:
                    return TextGenerator.Space(argLength);
                case 1:
                    return TextGenerator.CopyChar(argPool, argLength);
                default:
                    var vresult = new StringBuilder();
                    int vl = TextHelper.Len(argPool);
                    string vc;
                    float vn;
                    float vs;
                    Randomize();
                    while (vresult.Length < argLength)
                    {
                        vn = (vl + 1) * RandomFloat();
                        vs = Convert.ToInt32(Math.Floor(vn));
                        if (vs > 0)
                        {
                            if (vs > vl) vs = vl;
                            vc = TextHelper.Mid(argPool, Convert.ToInt32(vs), 1);
                            vresult.Append(vc);
                        }
                    }
                    return vresult.ToString();
            }
        }

        /// <summary>由易识别字符组成的随机字符串。</summary>
        /// <param name="argLength">随机字符串的长度。</param>
        public static string RandomLucid(int argLength)
        {
            return TextHelper.LCase(RandomCustom(Constant.LucidCollection, argLength));
        }

        /// <summary>由数字和字母组成的随机字符串。</summary>
        /// <param name="argLength">随机字符串的长度。</param>
        public static string RandomSimple(int argLength)
        {
            return TextHelper.LCase(RandomCustom(Constant.NumberCollection + Constant.LowerCollection, argLength));
        }

    }

}