BitArray(16) to HexString

Question

I'm trying to convert a BitArray to a Hex String

My test BitArray is "0000001010000000" and it should return "02 80" in Hex

Tried the following:

BitArray b = new BitArray(16);
b.Set(7, true);
b.Set(9, true);

Then, by examining the BitArray object I created and do get the 640 decimal value that corresponds to that binary string.

But I can't find the way to convert that to Hex.

I'm avoiding working with Byte Array which is a different class.

This works, but it's kind of complicated I'm sure there must be an easier way and I can't understand why I must switch the values.

byte[] bytes = new byte[2];
b.CopyTo(bytes, 0);
string Retorno = BitConverter.ToString(bytes);
string[] auxstr = Retorno.Split('-');
Retorno = auxstr[1] + "-" + auxstr[0];

Any advice?

Take a look at [this](http://stackoverflow.com/a/5533572/2030635) SO post — MX D, Jun 27 '16 at 14:43
Possible duplicate of [How do you convert Byte Array to Hexadecimal String, and vice versa?](http://stackoverflow.com/questions/311165/how-do-you-convert-byte-array-to-hexadecimal-string-and-vice-versa) — Sunny Patel, Jun 27 '16 at 14:43
You could convert it to `byte[]` like in [this question](http://stackoverflow.com/questions/560123/convert-from-bitarray-to-byte) and format the bytes individually. — Codor, Jun 27 '16 at 14:44

score 1 · Accepted Answer · answered Jun 27 '16 at 14:54

1

Then, by examining the BitArray object i created and do get the 640 decimal value that corresponds to that binary string.

So you only want to create a string representation of the hexadecimal value? This can be easily done like that:

int dec = 640;
string s = Convert.ToString(dec, 16);

or even string s = $"{dec:X}";

For leading zeros (as you show in your question) the best would be

string s = $"{dec:X4}";

Note that 640 as hexadecimal is 280 not 208 as you stated in your question.

An easy way to get the "value" of your BitArray is (for length <= 32):

int v = array.OfType<bool>().Select((b, i) => b ? 1 << i : 0).Sum()

answered Jun 27 '16 at 14:54

René Vogt

43,056
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Kind of, but i do need to get that decimal number from the BitArray first – Vyacheslav Shcherbakov Jun 27 '16 at 15:27
@VyacheslavShcherbakov does the last line of my answer do what you want? Or do you need something for bigger arrays? – René Vogt Jun 27 '16 at 15:27
Thank You very much – Vyacheslav Shcherbakov Jun 27 '16 at 15:44

score 0 · Answer 2 · answered Jun 27 '16 at 14:49

0

Try this,

string binary = "0000001010000000";

StringBuilder hexvalue= new StringBuilder(binary.Length / 8 + 1);           

int Len = binary.Length % 8;
if (Len != 0)
{               
     binary = binary.PadLeft(((binary.Length / 8) + 1) * 8, '0');
}

for (int i = 0; i < binary.Length; i += 8)
{
     string Bits = binary.Substring(i, 8);
     hexvalue.AppendFormat("{0:X2}", Convert.ToByte(Bits , 2));
}

binary =  hexvalue.ToString();

answered Jun 27 '16 at 14:49

sowjanya attaluri

903
2
9
27

The specification of the capacity when calling the constructor of `StringBuilder` is unnecessary. Also, some explanation about what this does would probably be very handy for the OP. – Maarten Jun 27 '16 at 14:57

Nikola.Lukovic · Answer 3 · 2016-06-27T15:21:15.133

Your bitArray sets and string representation are not the same.

You wrote 0000001010000000 which is actually set like this:

BitArray b = new BitArray(16);
b.Set(6, true);
b.Set(8, true);

But your code:

BitArray b = new BitArray(16);
b.Set(7, true);
b.Set(9, true);

actually produces this set of numbers:

0000000101000000

If you want to reproduce Hex 0280 than you should do this:

BitArray b = new BitArray(16);
b.Set(6, true);
b.Set(8, true);

var @string = String.Concat(b.Cast<bool>().Select(x=> { return x ? '1' : '0'; }));
var result = Convert.ToInt32(@string, 2).ToString("X4");

where result will have this value 0280

BitArray(16) to HexString

3 Answers3