一个简单的随机数字串函数，欢迎拍砖改进

 
static public string GenRandomString(int length)
  {
   if(length < 1)
    return "";
   Random ran = new Random();
   System.Text.StringBuilder  sb = new System.Text.StringBuilder();
   for(int i=0;i<length;i++)
    sb.Append(ran.Next(10));
   return sb.ToString();
  }