How to convert a string of bits to byte array

I have a string representing bits, such as:

"0000101000010000"

I want to convert it to get an array of bytes such as:

{0x0A, 0x10}

The number of bytes is variable but there will always be padding to form 8 bits per byte (so 1010 becomes 000010101).

Use the builtin Convert.ToByte() and read in chunks of 8 chars without reinventing the thing..

Unless this is something that should teach you about bitwise operations.

Update:

Stealing from Adam (and overusing LINQ, probably. This might be too concise and a normal loop might be better, depending on your own (and your coworker's!) preferences):

public static byte[] GetBytes(string bitString) {
    return Enumerable.Range(0, bitString.Length/8).
        Select(pos => Convert.ToByte(
            bitString.Substring(pos*8, 8),
            2)
        ).ToArray();
}

public static byte[] GetBytes(string bitString)
{
    byte[] output = new byte[bitString.Length / 8];

    for (int i = 0; i < output.Length; i++)
    {
        for (int b = 0; b <= 7; b++)
        {
            output[i] |= (byte)((bitString[i * 8 + b] == '1' ? 1 : 0) << (7 - b));
        }
    }

    return output;
}

Here's a quick and straightforward solution (and I think it will meet all your requirements): http://vbktech.wordpress.com/2011/07/08/c-net-converting-a-string-of-bits-to-a-byte-array/

This should get you to your answer: How can I convert bits to bytes?

You could just convert your string into an array like that article has, and from there use the same logic to perform the conversion.

Get the characers in groups of eight, and parse to a byte:

string bits = "0000101000010000";

byte[] data =
  Regex.Matches(bits, ".{8}").Cast<Match>()
  .Select(m => Convert.ToByte(m.Groups[0].Value, 2))
  .ToArray();

private static byte[] GetBytes(string bitString)
{
    byte[] result = Enumerable.Range(0, bitString.Length / 8).
        Select(pos => Convert.ToByte(
            bitString.Substring(pos * 8, 8),
            2)
        ).ToArray();

    List<byte> mahByteArray = new List<byte>();
    for (int i = result.Length - 1; i >= 0; i--)
    {
        mahByteArray.Add(result[i]);
    }

    return mahByteArray.ToArray();
}

private static String ToBitString(BitArray bits)
{
    var sb = new StringBuilder();

    for (int i = bits.Count - 1; i >= 0; i--)
    {
        char c = bits[i] ? '1' : '0';
        sb.Append(c);
    }

    return sb.ToString();
}

You can go any of below,

        byte []bytes = System.Text.Encoding.UTF8.GetBytes("Hi");
        string str = System.Text.Encoding.UTF8.GetString(bytes);


        byte []bytesNew = System.Convert.FromBase64String ("Hello!");
        string strNew = System.Convert.ToBase64String(bytesNew);