c#随机生成数字或字母

public class Rand
{
///

/// 生成随机数字
///

/// 生成长度
///
public static string Number(int Length)
{
return Number(Length, false);
}

///

/// 生成随机数字
///

/// 生成长度
/// 是否要在生成前将当前线程阻止以避免重复
///
public static string Number(int Length,bool Sleep)
{
if(Sleep)
System.Threading.Thread.Sleep(3);
string result = "";
System.Random random = new Random();
for (int i = 0; i < Length; i++)
{
result += random.Next(10).ToString();
}
return result;
}

///

/// 生成随机字母与数字
///

/// 生成长度
///
public static string Str(int Length)
{
return Str(Length, false);
}
///

/// 生成随机字母与数字
///

/// 生成长度
/// 是否要在生成前将当前线程阻止以避免重复
///
public static string Str(int Length, bool Sleep)
{
if(Sleep)
System.Threading.Thread.Sleep(3);
char[] Pattern = new char[] { '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' };
string result = "";
int n = Pattern.Length;
System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));
for (int i = 0; i < Length; i++)
{
int rnd = random.Next(0,n);
result += Pattern[rnd];
}
return result;
}


///

/// 生成随机纯字母随机数
///

/// 生成长度
///
public static string Str_char(int Length)
{
return Str_char(Length, false);
}

///

/// 生成随机纯字母随机数
///

/// 生成长度
/// 是否要在生成前将当前线程阻止以避免重复
///
public static string Str_char(int Length, bool Sleep)
{
if (Sleep) System.Threading.Thread.Sleep(3);
char[] Pattern

= new char[] { '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 result = "";
int n = Pattern.Length;
System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));
for (int i = 0; i < Length; i++)
{
int rnd = random.Next(0, n);
result += Pattern[rnd];
}
return result;
}
}