olidev olidev - 1 year ago 275
C# Question

convert byte array to int

I am trying to do some conversion in C#, and I am not sure how to do this:

private int byteArray2Int(byte[] bytes)
// bytes = new byte[] {0x01, 0x03, 0x04};

// how to convert this byte array to an int?

return BitConverter.ToInt32(bytes, 0); // is this correct?
// because if I have a bytes = new byte [] {0x32} => I got an exception

private string byteArray2String(byte[] bytes)
return System.Text.ASCIIEncoding.ASCII.GetString(bytes);

// but then I got a problem that if a byte is 0x00, it show 0x20

Could anyone give me some ideas?

Thanks in advance!

Answer Source

BitConverter is the correct approach.

Your problem is because you only provided 8 bits when you promised 32. Try instead a valid 32-bit number in the array, such as new byte[] { 0x32, 0, 0, 0 }.

If you want an arbitrary length array converted, you can implement this yourself:

ulong ConvertLittleEndian(byte[] array)
    int pos = 0;
    ulong result = 0;
    foreach (byte by in array) {
        result |= ((ulong)by) << pos;
        pos += 8;
    return result;

It's not clear what the second part of your question (involving strings) is supposed to produce, but I guess you want hex digits? BitConverter can help with that too, as described in an earlier question.

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