U3d：随机出任意的字符串

 string str="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    public void CreateRandomCode()
    {
        char[] chars=str.ToCharArray();
        StringBuilder strRan = new StringBuilder();
        System.Random ran = new System.Random();
        for (int i=0;i<6;i++)
        {
            strRan.Append(chars[ran.Next(0,36)]);
        }
        print(strRan);
    }