c# 获取随机数字/字符/时间

using System;
using System.Text;

namespace HuaTong.General.Utility
{
/// <summary>
/// 随机字符/数字
/// </summary>
public static class Randoms
{
static Random rd = new Random();
static DateTime _minDate = new DateTime(1990, 1, 1);
static DateTime _maxDate = DateTime.Now.Date;

/// <summary>
/// 随机int
/// </summary>
/// <returns></returns>
public static int RandomNumber()
{
return RandomNumber(0, int.MaxValue);
}
/// <summary>
/// 随机int
/// </summary>
/// <returns></returns>
public static int RandomNumber(int min, int max)
{
return rd.Next(min, max);
}

/// <summary>
/// 随机string
/// </summary>
/// <returns></returns>
public static string RandomString(int size, bool isNum = false, int isLower = -1)
{
StringBuilder builder = new StringBuilder();
char ch = '0';

for (int i = 0; i < size; i++)
{
if (isNum)
{
ch = Convert.ToChar(Convert.ToInt32(9 * rd.NextDouble() + 48));
}
else
{
if (isLower == -1)
{
int index = Convert.ToInt32(size * rd.NextDouble()) % 2 == 0 ? 65 : 97;
ch = Convert.ToChar(Convert.ToInt32(25 * rd.NextDouble() + index));
}
else if (isLower == 0)
{
ch = Convert.ToChar(Convert.ToInt32(25 * rd.NextDouble() + 65));
}
else if (isLower > 0)
{
ch = Convert.ToChar(Convert.ToInt32(25 * rd.NextDouble() + 97));
}
}
builder.Append(ch);
}

return builder.ToString();
}

/// <summary>
/// 随机datetime
/// </summary>
/// <returns></returns>
public static DateTime RandomDate()
{
return RandomDate(_minDate, _maxDate);
}
/// <summary>
/// 随机datetime
/// </summary>
/// <returns></returns>
public static DateTime RandomDate(DateTime minDate, DateTime maxDate)
{
int totalDays = (int)((TimeSpan)maxDate.Subtract(minDate)).TotalDays;
int randomDays = rd.Next(0, totalDays);
return minDate.AddDays(randomDays);
}

/// <summary>
/// 随机bool
/// </summary>
/// <returns></returns>
public static bool RandomBoolean()
{
return ((DateTime.Now.Second % 2) > 0);
}

/// <summary>
/// 随机char
/// </summary>
/// <returns></returns>
public static char RandomChar()
{
return Convert.ToChar(Convert.ToInt32(26 * rd.NextDouble() + 64));
}

/// <summary>
/// 随机byte
/// </summary>
/// <returns></returns>
public static byte RandomByte()
{
return RandomByte(0, byte.MaxValue);
}
/// <summary>
/// 随机byte
/// </summary>
/// <returns></returns>
public static byte RandomByte(byte min, byte max)
{
return (byte)RandomNumber((int)min, (int)max);
}

/// <summary>
/// 随机shrot
/// </summary>
/// <returns></returns>
public static short RandomShort()
{
return RandomShort(0, short.MaxValue);
}
/// <summary>
/// 随机short
/// </summary>

/// <returns></returns>
public static short RandomShort(short min, short max)
{
return (short)RandomNumber((int)min, (int)max);
}
}
}