C#: int 与 byte[] 互转

        public static int ToInt32(params byte[] v) {
            var r = ;
            var len = v.Length;
            if (len > ) {
                len = ;
            }
            for (var i = ; i < len; i++) {
                r |= v[i] <<  * (len - i - );
            }
            return r;
        }

        public static byte[] ToBytes(int v) {
            var len = ;
            for (var i = ; i < ; i++) {
                if (v >>  * i < ) {
                    len = i + ;
                    break;
                }
            }
            var bs = new byte[len];
            for (var j = ; j < bs.Length; j++) {
                bs[j] = (byte)(v >> (bs.Length - j - ) * );
            }
            return bs;
        }