C# how convert large HEX string to binary

jayt csharp picture jayt csharp · Jul 7, 2011 · Viewed 67.5k times · Source

I have a string with 14 characters . This is a hex represantation of 7bytes. I want to convert it to binary. I tried using Convert.ToString(Convert.ToInt32(hexstring, 16), 2); For small strings this works but for 14 characters it will not work because the result is too large. How can i manage this? Keep in mind that the output of the conversion should be a binary string with a lengeth of 56 characters (we must keep the leading zeros). (e.g. conversion of (byte)0x01 should yield "00000001" rather than "1")

Answer

Guffa picture Guffa · Jul 7, 2011

You can just convert each hexadecimal digit into four binary digits:

string binarystring = String.Join(String.Empty,
  hexstring.Select(
    c => Convert.ToString(Convert.ToInt32(c.ToString(), 16), 2).PadLeft(4, '0')
  )
);

You need a using System.Linq; a the top of the file for this to work.