Difference between C# byte format

June 20, 2022

I’m trying to download some bytes over my xampp server to use it inside my C# program, but there is a difference between the length of the bytes as shown here :

        WebClient wc = new WebClient();
        byte[] bytesweb = wc.DownloadData(@"http://127.0.0.1/test.txt");

        int lenweb = bytesweb.Length; //The value of lenweb is 69

And then when I use the same bytes directly inside the program as shown here :

        byte[] bytesapp = new byte[] { 0x00, 0x00, 0x40, 0x00, 0x00, 0xe8, 0x10, 0x00, 0x00, 0x00, 0x40 };

        int lenapp = bytesapp.Length; //The value of lenapp is 11

So I can’t understand what changed between thoses 2, what to do so the length value is equal to "11" while importing it using my server

nb : the value of "test.txt" is : { 0x00, 0x00, 0x40, 0x00, 0x00, 0xe8, 0x10, 0x00, 0x00, 0x00, 0x40 };

>Solution :

nb : the value of "test.txt" is : { 0x00, 0x00, 0x40, 0x00, 0x00, 0xe8, 0x10, 0x00, 0x00, 0x00, 0x40 };

So, your file contains the literal text { 0x00, 0x00, 0x40, 0x00, 0x00, 0xe8, 0x10, 0x00, 0x00, 0x00, 0x40 };.

This is a 69-byte text which, when interpreted as a C# code snippet, represents a 11-byte byte array. This explains the difference you see.

How do you fix this? Don’t store your byte arrays as text, store them as a bytes:

byte[] bytesapp = new byte[] { 0x00, 0x00, 0x40, 0x00, 0x00, 0xe8, 0x10, 0x00, 0x00, 0x00, 0x40 };

// This creates the file you want to put on your web server.
File.WriteAllBytes(@"C:\temp\test.bin", bytesapp);

(Alternatively, you could write code that parses your text file and converts it to a "real" byte array. This question contains example code that can do this for you if you store your data in the following format: 0000400000e81000000040.)