Question

I have an object array containing array of a different type that is not known at compile time, but turns out to be int[], double[] etc.

I want to save these arrays to disk and I don’t really need to process their contents online, so I looking for a way to cast the object[] to a byte[] that I then can write to disk.

How can I achieve this?

Answer 1

You may use binary serialization and deserialization for Serializable types.

using System.Runtime.Serialization.Formatters.Binary;

BinaryFormatter binary = BinaryFormatter();
using (FileStream fs = File.Create(file))
{
    bs.Serialize(fs, objectArray);
}

Edit: If all these elements of an array are simple types then use BitConverter.

object[] arr = { 10.20, 1, 1.2f, 1.4, 10L, 12 };
using (MemoryStream ms = new MemoryStream())
{
    foreach (dynamic t in arr)
    {
        byte[] bytes = BitConverter.GetBytes(t);
        ms.Write(bytes, 0, bytes.Length);
    }
}