ASP.NET 返回随机数实现代码

/// <summary> 
/// 返回随机数 
/// </summary> 
/// <param name="VcodeNum"></param> 
/// <returns></returns> 
public string RndNum(int VcodeNum) 
{ 
string Vchar = "0,1,2,3,4,5,6,7,8,9"; 
string[] VcArray = Vchar.Split(','); 
string VNum = "";//由于字符串很短，就不用StringBuilder了 
int temp = -1;//记录上次随机数值，尽量避免生产几个一样的随机数 
//采用一个简单的算法以保证生成随机数的不同 
Random rand = new Random(); 
for (int i = 1; i < VcodeNum + 1; i++) 
{ 
if (temp != -1) 
{ 
rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks)); 
} 
//int t = rand.Next(35) ; 
int t = rand.Next(9); 
if (temp != -1 && temp == t) 
{ 
return RndNum(VcodeNum); 
} 
temp = t; 
VNum += VcArray[t]; 
} 
return VNum; 
} 
 
调用时只需要 string code = RndNum(4); 
这样取得了4位随机数． 
如果需要字母随机数，则 
string Vchar = "0,1,2,3,4,5,6,7,8,9，A,B";把字母加上去． 
同时修改int t = rand.Next(9);中的9改成Vchar的长度但可．