CODEWITHSUNDEEP
c#arraysbitarray
vidya sagar
vidya sagar

Reputation: 2009

Converting binary data to bytes in c#

we have a text file containing binary values. say, we have a file "file.txt",it contains binary datat, say 11001010 the size of this file is 8 bytes. but we want these 8 bytes to be read as bits i.e. 8 bits and thus make 8 bits into 1 byte. How can we do it? we just know the procedure: 1. take a buffer and read individual value into buffer 2.if the buffer value reaches 8,make those 8 bits into a byte and write to a file.

thanks in advance.

Upvotes: 1

Views: 3231

Answers (3)

dice
dice

Reputation: 2880

Just in case we are talking about bytes and not chars:

        byte output;
        using (var inFile = File.OpenRead("source"))
        {
            int offset = 0;
            var data = new byte[8];
            while (inFile.Read(data, offset, 8) == 8)
            {
                output = (byte)(data[0] << 7);
                output += (byte)(data[1] << 6);
                output += (byte)(data[2] << 5);
                output += (byte)(data[3] << 4);
                output += (byte)(data[4] << 3);
                output += (byte)(data[5] << 2);
                output += (byte)(data[6] << 1);
                output += (byte)data[7];

                offset += 8;

                // write your output byte
            }
        }

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1503180

Given a string, I suspect you want Convert.ToByte(text, 2);

For more than a single byte, I don't think there's anything built in to convert a long string to a byte array like this, but you could use Substring repeatedly if you want.

Upvotes: 3

Timwi
Timwi

Reputation: 66604

The following code reads such a text file as you describe. If the file contains a number of binary digits that is not divisible by 8, the extraneous digits are discarded.

using (var fileToReadFrom = File.OpenRead(@"..."))
using (var fileToWriteTo = File.OpenWrite(@"..."))
{
    var s = "";
    while (true)
    {
        var byteRead = fileToReadFrom.ReadByte();
        if (byteRead == -1)
            break;
        if (byteRead != '0' && byteRead != '1')
        {
            // If you want to throw on unexpected characters...
            throw new InvalidDataException(@"The file contains a character other than 0 or 1.");
            // If you want to ignore all characters except binary digits...
            continue;
        }
        s += (char) byteRead;
        if (s.Length == 8)
        {
            fileToWriteTo.WriteByte(Convert.ToByte(s, 2));
            s = "";
        }
    }
}

Upvotes: 1

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