java c#指定长度 中int与byte数组互转代码详细分析

http://www.2cto.com/kf/201502/374916.html

int 转 byte

        public static byte[] int2Bytes(int value, int len)
        {
            byte[] b = new byte[len];
            for (int i = 0; i < len; i++)
            {
                b[len - i - 1] = (byte)((value >> 8 * i) & 0xff);
            }
            return b;
        }

byte 转 int

public static int bytes2Int(byte[] b, int start, int len) {
    int sum = 0;
    int end = start + len;
    for (int i = start; i < end; i++) {
        int n = ((int)b[i]) & 0xff;
        n <<= (--len) * 8;
        sum += n;
    }
    return sum;
}