C# – How to Convert BYTE Array to INT

arraysc++type-conversion

I have this kind of code

static void Main(string[] args)
{
     byte[] array = new byte[2] { 0x00, 0x1f };
     Console.WriteLine(BitConverter.ToInt32(array, 0));
}

However it does not work. It throws an exception:

Destination array is not long enough to copy all the items in the
collection. Check array index and length.

What is wrong?

Best Answer

As the name suggests, an Int32 is 32 bits, or 4 bytes, so if you want to convert a byte array to an Int32, it needs to have a length of at least 4, (or more precisely, it needs to have least 4 bytes after the start position).

If all you have is two bytes, maybe you meant to use ToInt16?

Related Solutions

C# – How to Convert Value Type to byte[]

To convert any value types (not just primitive types) to byte arrays and vice versa:

    public T FromByteArray<T>(byte[] rawValue)
    {
        GCHandle handle = GCHandle.Alloc(rawValue, GCHandleType.Pinned);
        T structure = (T)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(T));
        handle.Free();
        return structure;
    }

    public byte[] ToByteArray(object value, int maxLength)
    {
        int rawsize = Marshal.SizeOf(value);
        byte[] rawdata = new byte[rawsize];
        GCHandle handle =
            GCHandle.Alloc(rawdata,
            GCHandleType.Pinned);
        Marshal.StructureToPtr(value,
            handle.AddrOfPinnedObject(),
            false);
        handle.Free();
        if (maxLength < rawdata.Length) {
            byte[] temp = new byte[maxLength];
            Array.Copy(rawdata, temp, maxLength);
            return temp;
        } else {
            return rawdata;
        }
    }

C# – Converting int[] to byte[]

If you want a bitwise copy, i.e. get 4 bytes out of one int, then use Buffer.BlockCopy:

byte[] result = new byte[intArray.Length * sizeof(int)];
Buffer.BlockCopy(intArray, 0, result, 0, result.Length);

Don't use Array.Copy, because it will try to convert and not just copy. See the remarks on the MSDN page for more info.

Best Answer

Related Solutions

C# – How to Convert Value Type to byte[]

C# – Converting int[] to byte[]

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