using System;
namespace DotNet.Utilities
{
/// <summary>
/// 使用Random类生成伪随机数
/// </summary>
public class RandomHelper
{
//随机数对象
private Random _random;
#region 构造函数
/// <summary>
/// 构造函数
/// </summary>
public RandomHelper()
{
//为随机数对象赋值
this._random = new Random();
}
#endregion
#region 生成一个指定范围的随机整数
/// <summary>
/// 生成一个指定范围的随机整数，该随机数范围包括最小值，但不包括最大值
/// </summary>
/// <param name="minNum">最小值</param>
/// <param name="maxNum">最大值</param>
public int GetRandomInt(int minNum, int maxNum)
{
return this._random.Next(minNum, maxNum);
}
#endregion
#region 生成一个0.0到1.0的随机小数
/// <summary>
/// 生成一个0.0到1.0的随机小数
/// </summary>
public double GetRandomDouble()
{
return this._random.NextDouble();
}
#endregion
#region 对一个数组进行随机排序
/// <summary>
/// 对一个数组进行随机排序
/// </summary>
/// <typeparam name="T">数组的类型</typeparam>
/// <param name="arr">需要随机排序的数组</param>
public void GetRandomArray<T>(T[] arr)
{
//对数组进行随机排序的算法:随机选择两个位置，将两个位置上的值交换
//交换的次数,这里使用数组的长度作为交换次数
int count = arr.Length;
//开始交换
for (int i = 0; i < count; i++)
{
//生成两个随机数位置
int randomNum1 = GetRandomInt(0, arr.Length);
int randomNum2 = GetRandomInt(0, arr.Length);
//定义临时变量
T temp;
//交换两个随机数位置的值
temp = arr[randomNum1];
arr[randomNum1] = arr[randomNum2];
arr[randomNum2] = temp;
}
}
// 一：随机生成不重复数字字符串
private int rep = 0;
public string GenerateCheckCodeNum(int codeCount)
{
string str = string.Empty;
long num2 = DateTime.Now.Ticks + this.rep;
this.rep++;
Random random = new Random(((int)(((ulong)num2) & 0xffffffffL)) | ((int)(num2 >> this.rep)));
for (int i = 0; i < codeCount; i++)
{
int num = random.Next();
str = str + ((char)(0x30 + ((ushort)(num % 10)))).ToString();
}
return str;
}
//方法二：随机生成字符串（数字和字母混和）
public string GenerateCheckCode(int codeCount)
{
string str = string.Empty;
long num2 = DateTime.Now.Ticks + this.rep;
this.rep++;
Random random = new Random(((int)(((ulong)num2) & 0xffffffffL)) | ((int)(num2 >> this.rep)));
for (int i = 0; i < codeCount; i++)
{
char ch;
int num = random.Next();
if ((num % 2) == 0)
{
ch = (char)(0x30 + ((ushort)(num % 10)));
}
else
{
ch = (char)(0x41 + ((ushort)(num % 0x1a)));
}
str = str + ch.ToString();
}
return str;
}
#region
/// <summary>
/// 从字符串里随机得到，规定个数的字符串.
/// </summary>
/// <param name="allChar"></param>
/// <param name="CodeCount"></param>
/// <returns></returns>
private string GetRandomCode(string allChar, int CodeCount)
{
//string allChar = "1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,i,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
string[] allCharArray = allChar.Split(',');
string RandomCode = "";
int temp = -1;
Random rand = new Random();
for (int i = 0; i < CodeCount; i++)
{
if (temp != -1)
{
rand = new Random(temp * i * ((int)DateTime.Now.Ticks));
}
int t = rand.Next(allCharArray.Length - 1);
while (temp == t)
{
t = rand.Next(allCharArray.Length - 1);
}
temp = t;
RandomCode += allCharArray[t];
}
return RandomCode;
}
#endregion
#endregion
}
}
