在项目开发中，一般都会使用到“随机数”，但是在DotNet中的随机数并非真正的随机数，可在一些情况下生成重复的数字，现在总结一下在项目中生成随机数的方法。
1.随机布尔值：
/// <summary>
/// 随机布尔值
/// </summary>
/// <param name="random"></param>
/// <returns>随机布尔值</returns>
public static bool NextBoolean(this Random random)
{
if (random == null)
{
throw new ArgumentNullException("random");
}
return random.NextDouble() > 0.5;
}2.指定枚举类型的随机枚举值：
/// <summary>
/// 指定枚举类型的随机枚举值
/// </summary>
/// <param name="random"></param>
/// <returns>指定枚举类型的随机枚举值</returns>
public static T NextEnum<T>(this Random random) where T : struct
{
var type = typeof(T);
if (!type.IsEnum)
{
throw new InvalidOperationException();
}
var array = System.Enum.GetValues(type);
var index = random.Next(array.GetLowerBound(0), array.GetUpperBound(0) + 1);
return (T)array.GetValue(index);
}3.随机数填充的指定长度的数组：
/// <summary>
/// 随机数填充的指定长度的数组
/// </summary>
/// <param name="random"></param>
/// <param name="length">数组长度</param>
/// <returns>随机数填充的指定长度的数组</returns>
public static byte[] NextBytes(this Random random, int length)
{
if (length < 0)
{
throw new ArgumentOutOfRangeException("length");
}
var data = new byte[length];
random.NextBytes(data);
return data;
}4. 数组中的随机元素：
/// <summary>
/// 数组中的随机元素
/// </summary>
/// <typeparam name="T">元素类型</typeparam>
/// <param name="random"></param>
/// <param name="items">元素数组</param>
/// <returns>元素数组中的某个随机项</returns>
public static T NextItem<T>(this Random random, T[] items)
{
return items[random.Next(0, items.Length)];
}5.指定时间段内的随机时间值：
/// <summary>
/// 指定时间段内的随机时间值
/// </summary>
/// <param name="random"></param>
/// <param name="minValue">时间范围的最小值</param>
/// <param name="maxValue">时间范围的最大值</param>
/// <returns>指定时间段内的随机时间值</returns>
public static DateTime NextDateTime(this Random random, DateTime minValue, DateTime maxValue)
{
var ticks = minValue.Ticks + (long)((maxValue.Ticks - minValue.Ticks) * random.NextDouble());
return new DateTime(ticks);
}6. 随机时间值：
/// <summary>
/// 随机时间值
/// </summary>
/// <param name="random"></param>
/// <returns>随机时间值</returns>
public static DateTime NextDateTime(this Random random)
{
return NextDateTime(random, DateTime.MinValue, DateTime.MaxValue);
}7.获取指定的长度的随机数字字符串：
/// <summary>
/// 获取指定的长度的随机数字字符串
/// </summary>
/// <param name="random"></param>
/// <param name="length">要获取随机数长度</param>
/// <returns>指定长度的随机数字符串</returns>
public static string GetRandomNumberString(this Random random, int length)
{
if (length < 0)
{
throw new ArgumentOutOfRangeException("length");
}
char[] pattern = { ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘, ‘7‘, ‘8‘, ‘9‘ };
var result = "";
var n = pattern.Length;
for (var i = 0; i < length; i++)
{
var rnd = random.Next(0, n);
result += pattern[rnd];
}
return result;
}8.获取指定的长度的随机字母字符串：
/// <summary>
/// 获取指定的长度的随机字母字符串
/// </summary>
/// <param name="random"></param>
/// <param name="length">要获取随机数长度</param>
/// <returns>指定长度的随机字母组成字符串</returns>
public static string GetRandomLetterString(this Random random, int length)
{
if (length < 0)
{
throw new ArgumentOutOfRangeException("length");
}
char[] pattern =
{
‘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‘
};
var result = "";
var n = pattern.Length;
for (var i = 0; i < length; i++)
{
var rnd = random.Next(0, n);
result += pattern[rnd];
}
return result;
}9.获取指定的长度的随机字母和数字字符串：
/// <summary>
/// 获取指定的长度的随机字母和数字字符串
/// </summary>
/// <param name="random"></param>
/// <param name="length">要获取随机数长度</param>
/// <returns>指定长度的随机字母和数字组成字符串</returns>
public static string GetRandomLetterAndNumberString(this Random random, int length)
{
if (length < 0)
{
throw new ArgumentOutOfRangeException("length");
}
char[] pattern =
{
‘0‘, ‘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‘
};
var result = "";
var n = pattern.Length;
for (var i = 0; i < length; i++)
{
var rnd = random.Next(0, n);
result += pattern[rnd];
}
return result;
}生成随机数的方式较多，可根据具体的要求来生成对应的随机数。
本文出自 “彭泽0902” 博客，请务必保留此出处http://pengze0902.blog.51cto.com/7693836/1872900
原文地址：http://pengze0902.blog.51cto.com/7693836/1872900
