C#根据生日计算所属十二星座

 /// <summary>
        /// 出生月份
        /// 出生日期
        /// </summary>
        /// <returns>星座</returns>
        public static Func<int, int, string> GetConstellation()
        {
            return (x, y) =>
            {
                string str = string.Empty;
                float birthdayF = x == 1 && y < 20 ?
                    13 + y / 100f :
                    x + y / 100f;

                float[] bound = { 1.20F, 2.20F, 3.21F, 4.21F, 5.21F, 6.22F, 7.23F, 8.23F, 9.23F, 10.23F, 11.21F, 12.22F, 13.20F };

                Constellation[] constellations = new Constellation[12];
                for (int i = 0; i < constellations.Length; i++)
                    constellations[i] = (Constellation)(i + 1);

                for (int i = 0; i < bound.Length - 1; i++)
                {
                    float b = bound[i];
                    float nextB = bound[i + 1];
                    if (birthdayF >= b && birthdayF < nextB)
                        str = constellations[i].ToString();
                }
                return str;
            };
        }

public enum Constellation
        {
            水瓶座 = 1,   //  1.20 - 2.18
            双鱼座 = 2,   //  2.19 - 3.20
            白羊座 = 3,   //  3.21 - 4.19
            金牛座 = 4,   //  4.20 - 5.20
            双子座 = 5,   //  5.21 - 6.21
            巨蟹座 = 6,   //  6.22 - 7.22
            狮子座 = 7,   //  7.23 - 8.22
            处女座 = 8,   //  8.23 - 9.22
            天秤座 = 9,   //  9.23 - 10.23
            天蝎座 = 10,  //  10.24 - 11.22
            射手座 = 11,  //  11.23 - 12.21
            摩羯座 = 12,  //  12.22 - 1.19
        }