C# hex to string problems

Question

i making a program with CSharp Language. But, I have a big problem. I'm making a program that reading a file by a hex and converting hex to string. but, i can't get string perfectly. The blue one is a hex code that i want to converting to string. this is hex code...

but i cant get only 59fd50a62fb9a8ef, not including a file extension.

i want to get perfect string like 59fd50a62f9a8ef.bmp

How can i do ?

This is a source code that converting a hex to string.

    string toString(string hexString)
    {
        var bytes = new byte[hexString.Length / 2];
        for (var i = 0; i < bytes.Length; i++)
        {
            bytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
        }
        return Encoding.Unicode.GetString(bytes);
    }

Answer 1

You cannot get the file extension from the bytes you highlighted. As far as I can tell they contain a hexadecimal filename, which you have extracted successfully already, an end of string character (two zeroes), the start of a bitmap ( BM ) and the length of the bitmap ( 36 10 00 00 in little endian ). So, to get a filename you just have to append .bmp to your hexadecimal string.

If, however, the image is not always a bitmap, then you should create a function that deduces the filetype from the bytes after the end of string character.