C# ±180的值转成0-360

     /// <summary>
        /// 正负180， 0--->360
        /// </summary>
        /// <param name="p"></param>
        /// <returns></returns>
        public static double Conv_k(double p)
        {
            while (p > 180) 
            {
                p = p - 360;
            }
            while (p < -180)
            {
                p = p + 360;
            }

            if(p<=90)
            {
                return 90 - p;
            }
            if(p>90)
            {
                return 360 + (90 - p);
            }
            return 0;
        }