BitConverter.GetBytes in place

Question

I need to get values in UInt16 and UInt64 as Byte[]. At the moment I am using BitConverter.GetBytes, but this method give

Answer 1

It seems that you wish to avoid, for some reason, creating any temporary new arrays. And you also want to avoid unsafe code.

You could pin the object and then copy to the array.

public static void ToBytes(ulong value, byte[] array, int offset) 
{
    GCHandle handle = GCHandle.Alloc(value, GCHandleType.Pinned);
    try
    {
        Marshal.Copy(handle.AddrOfPinnedObject(), array, offset, 8);
    }
    finally
    {
        handle.Free();
    }
}