CODEWITHSUNDEEP
c#binaryasciiencoding
Sam
Sam

Reputation: 2970

Better way to convert a binary format string(0 and 1) to byte[]?

I have write this, is a good one?

byte[] ConvertToBytes(string b)
    {
        BitArray bits = new BitArray(b.ToList().ConvertAll<bool>(x => x == '1').ToArray());

        byte[] ret = new byte[bits.Length];
        bits.CopyTo(ret, 0);

        return ret;
    }

(the array must be readable as an ascii string)

Upvotes: 2

Views: 4358

Answers (6)

pasx
pasx

Reputation: 2975

Append all the chars into a long as below:

var l = 0L;
foreach (var c in s)
{
    l <<= 1;
    l += c;
}
var b = BitConverter.GetBytes(l);

Upvotes: 0

Parimal Raj
Parimal Raj

Reputation: 20585

I can suggest a efficient way, thought it must not be that hard to implement.

I am assuming that the string will well formed that it is a binary representation in string format.

private static byte[] BinStringToBytes(string binary)
{
    //make sure the string length is multiple of 32, if not pad it with zeroes
    var neededZeros = 32 - (binary.Length % 32);

    if (neededZeros > 0)
        binary = string.Concat(new string('0', neededZeros), binary);

    var blocks = binary.Length / 32;

    var binbytes = new byte[blocks * 4];

    for (var i = 0; i < blocks; i++)
    {
        var numstr = binary.Substring(i * 32, 32);
        var num = Convert.ToUInt32(numstr, 2);
        var bytes = BitConverter.GetBytes(num);
        Array.Copy(bytes, 0, binbytes, i * 4, 4);
    }

    return binbytes;
}

Upvotes: 1

dav_i
dav_i

Reputation: 28107

Alternative:

You may be better off not using byte[] but actually just storing the binary number as an integer:

Convert.ToInt32("1011", 2) // returns 11

And the other way round:

Convert.ToString(11, 2) // returns "1011"

And if you need to get the nth bit across (from right):

public int GetNthBit(int binary, int n)
{
    return (binary >> n) % 2;
}

Usage:

GetNthBit(11, 2) // returns 0

Upvotes: 1

Lucas_Santos
Lucas_Santos

Reputation: 4740

string array = "1010101";
byte[] sequence = array.Select(c => Convert.ToByte(c.ToString())).ToArray();

Or 

byte[] bytes = Encoding.ASCII.GetBytes(array);

Upvotes: 3

Matthew Watson
Matthew Watson

Reputation: 109597

It's possible I misunderstand the question, but:

public byte[] BitStringToAsciiArray(string bits)
{
    return Encoding.ASCII.GetBytes(bits);
}

However, it doesn't give any error if any of the characters in the input string are something other than '0' or '1'.

But otherwise it does return an array of bytes each which is 48 for a '0' in the input string and 49 for a '1' in the input string. These are the ASCII codes for '0' and '1' respectively.

Upvotes: 0

Abbas
Abbas

Reputation: 14432

Mehrdad has a good answer to your question. The code:

static byte[] GetBytes(string str)
{
    byte[] bytes = new byte[str.Length * sizeof(char)];
    System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
    return bytes;
}

Upvotes: 0

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