c# - write string that contains hex values as bytes

Question

let's say I have a string

string hex = "55 6E 6B 6E 6F 77 6E 20 53 70 61 63 65"

I want to write these to a file but they should be the bytes itself. so the result would be Unknown Space.

Is there any way to do that directly instead of first encoding it to utf-8 and write that to the file? the reason I'm asking is that sometimes there is the special character of utf-8 in the (like eg 0xE28780 ) which wouldn't work well if I first split the string into chars of each value.

Thanks a lot!

Answer 1

with string.Split , Convert.ToByte , and FileStream or File.WriteAllBytes

string hex = "55 6E 6B 6E 6F 77 6E 20 53 70 61 63 65";
var bytes = hex.Split(' ')
               .Select(x => Convert.ToByte(x, 16))
               .ToArray();

using (var fs = new FileStream(@"D:\test2.dat",FileMode.Create))
   fs.Write(bytes,0,bytes.Length);

// or even easier 

File.WriteAllBytes(@"D:\test2.dat",bytes);

---

String.Split Method

Returns a string array that contains the substrings in this instance that are delimited by elements of a specified string or Unicode character array.

Convert.ToByte Method (String, Int32)

Converts the string representation of a number in a specified base to an equivalent 8-bit unsigned integer.

FileStream Class

Provides a Stream for a file, supporting both synchronous and asynchronous read and write operations.

File.WriteAllBytes Method (String, Byte[])

Creates a new file, writes the specified byte array to the file, and then closes the file. If the target file already exists, it is overwritten.