public static string CreateAuthStr(int len, bool onlyNum)
{
if (!onlyNum)
{
return(TextUtility.CreateAuthStr(len));
}
StringBuilder stringBuilder = new StringBuilder();
Random random = new Random();
for (int i = 0; i < len; i++)
{
int num = random.Next();
stringBuilder.Append((char)(48 + (ushort)(num % 10)));
}
return(stringBuilder.ToString());
}