How do you convert 3 bytes into a 24 bit number in C#?

Question

I have an array of bytes that I read from a header section of a message. These bytes contain the length of the message. There never are more than 3 bytes and they are ordere

Answer 1

Use methods like BitConverter.ToInt32, but realize that you'll need 4 bytes for 32 bit quantities.

var data = new byte[] {39, 213, 2, 0};
int integer = BitConverter.ToInt32(data, 0);

There are also other methods to convert to and from other types like Single and Double.