Reading bits in C#

[J. Cathcart]

Hi
I wanna decompose a number read from file to bits (o,1). Also I wanna know if there is something similar 2 union in C++

[Çòùrtnèy_Ч]

There's a class called (I believe) BinaryReader that does exactly what you want... It takes a Stream in the constructor and then you can read bits out in any form you like... I don't have the documentation in front of me right now.. but it works like this:

Stream s = File.OpenRead(@"path/to/file.ext");
BinaryReader reader = new BinaryReader(s);

// Now you can read bits out of the stream
byte b;
b = reader.ReadByte(); // read a byte out

int i;
i = reader.ReadInt(); // read 4 bytes out

Sincerely
CourtneyDS

[J. Cathcart]

Thank u very much,
but the problem that I can read bytes wiz that reader but I wanna read bits tha compose this bytes ?, Do u have any idea about that?

[Çòùrtnèy_Ч]

Once you have the byte.. you're pretty well set... You can just add the byte with a mask to get the value of a specific bit...
For example.. say you want to know the value of the right-most bit of the byte...

Read byte: 11001010
Apply mask:00000001

When you add those two things.. you'll wind up with a 0 if the bit in question was a 0.. and a 1 otherwise... So your code might look like this:

// Reader is a BinaryReader
byte b = reader.ReadByte();

// Is the lowest-bit a 1?
if (b & 0x01 == 0x01) {
// lowest bit was set

}

^^ If this doesn't make sense to you.. I recommend reading a bit on working with binary operators ...:

Sincerely
CourtneyDS

[J. Cathcart]

Thank you very much Courtney,
It works! It works!