bytearray - Splitting a byte[] into multiple byte[] arrays in C#

Question

I am trying to "chunk" up the bytes of an image. This will allow me to upload a large image in portions. I have the image currently stored as one large byte[]. I would like to split the byte array into byte[]'s with a maxlength of 512 elements. However, I'm not sure how to do this in the most efficient way.

Does anyone know how I can do this in the most efficient manner?

Answer 1

I wrote an extension for this, originally for strings, but decided to make it generic.

    public static T[] CopySlice<T>(this T[] source, int index, int length, bool padToLength = false)
    {
        int n = length;
        T[] slice = null;

        if (source.Length < index + length)
        {
            n = source.Length - index;
            if (padToLength)
            {
                slice = new T[length];
            }
        }

        if(slice == null) slice = new T[n];
        Array.Copy(source, index, slice, 0, n);
        return slice;
    }

    public static IEnumerable<T[]> Slices<T>(this T[] source, int count, bool padToLength = false)
    {
        for (var i = 0; i < source.Length; i += count)
            yield return source.CopySlice(i, count, padToLength);
    }

Basically, you can use it like so:

byte[] myBytes; // original byte array

foreach(byte[] copySlice in myBytes.Slices(10))
{
    // do something with each slice
}

Edit: I also provided an answer on SO using Buffer.BlockCopy here but BlockCopy will only work on byte[] arrays, so a generic version for strings wouldn't be possible.