byte array 여러개를 하나의 array로 합치기

byte[] rv = new byte[a1.Length + a2.Length + a3.Length];
System.Buffer.BlockCopy(a1, 0, rv, 0, a1.Length);
System.Buffer.BlockCopy(a2, 0, rv, a1.Length, a2.Length);
System.Buffer.BlockCopy(a3, 0, rv, a1.Length + a2.Length, a3.Length);

IEnumerable<byte> rv = a1.Concat(a2).Concat(a3);

private byte[] Combine(params byte[][] arrays)
{
    byte[] rv = new byte[arrays.Sum(a => a.Length)];
    int offset = 0;
    foreach (byte[] array in arrays) {
        System.Buffer.BlockCopy(array, 0, rv, offset, array.Length);
        offset += array.Length;
    }
    return rv;
}

 

출처 : https://stackoverflow.com/questions/415291/best-way-to-combine-two-or-more-byte-arrays-in-c-sharp

Best way to combine two or more byte arrays in C#