.NET Framework - read binary file to a byte array

Asked By Siva

25-Feb-10 06:41 AM

how would i read a binary file into a byte array efficiently?

25-Feb-10 06:54 AM

Hi Siva,


this is the fastest way to do it in one shot:

byte[] yourFileBytes = File.ReadAllBytes(@"C:\Path\To\Your\File.txt");

Regards

Kerem

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Beste Gr??sse / Best regards / Votre bien devoue
Kerem G??mr??kc??
Latest Project: http://www.pro-it-education.de/software/deviceremover
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25-Feb-10 07:16 AM

byte [] data = File.ReadAllBytes("Somefilename.bin");

Mike

25-Feb-10 08:09 AM

thanks and how do convert this byte[] to string?

25-Feb-10 08:19 AM

First you need to know what kind of character set is used to encode the
string in those bytes. Once you know it, you use the GetString method in
System.Text.Encoding to perform the conversion:

string s = System.text.Encoding.UTF8.GetString(data);

The preceding presumes that the file was encoded in UTF8, but if another
encoding was used you need to use the proper encoding. For instance, if the
file used the Windows-1252 character set, you could use this:

string s = System.text.Encoding.GetEncoding(1252).GetString(data);

25-Feb-10 09:20 AM

Why not just read the file as a text file directly into a string?  Is
there a reason that you need the same data twice, once as bytes and
once as a string?

rossum

25-Feb-10 09:50 AM

I thought you said the file had binary data... :)

You could perhaps use this instead:

string txt = File.ReadAllText("somefile.bin");

Mike

26-Feb-10 06:58 AM

hello,
Sorry for the confusion, here is the code,

byte[] data = File.ReadAllBytes(<filepath>);
MD5 md5 = MD5.Create();
byte[] hash = md5.ComputeHash(data);

now i need to convert this 'hash' to string with hexadecimal representation.
is a ready made method available already?

Siva

26-Feb-10 07:12 AM

Siva,

Depending on the exact format you want, you could do something like:

foreach (byte b in hash)
Console.WriteLine(b.ToString("x"));

Mike

26-Feb-10 08:27 AM

Does it need to be hexadecimal? There is a more compact representation which
is called "Base 64". This instruction produces a base 64 string from your
byte array:

string s = Convert.ToBase64String(hash);

26-Feb-10 10:36 AM

I'd amend that to

Console.WriteLine(b.ToString("x:2"))

So that all bytes will be 2 characters, or those pesky less-than-16 bytes
will screw up your string.

26-Feb-10 05:04 PM

Oh, you just took all of the fun out of parsing the result string! :)

--
Mike

12-Mar-10 03:55 PM

For posterity I will admend that a second time and remove the colon that I
typed for no good reason:

Console.WriteLine(b.ToString("x2"))