How to convert a string to a byte array in C#

C# allow to easily convert a string to a byte array using the Encoding.ASCII.GetBytes function.
A sample usage is

string sample = "This is a simple string";
byte[] content = Encoding.ASCII.GetBytes(sample);

Note that this method only works if the string is with the ASCII format.

The framework supports other encodings (UTF8, Unicode, UTF32, ...) but a more generic method is needed.
The ideal solution if to don't need to worry about the encoding if the bytes don't need to be interpreted.
A use case for this solution is to transfer a file from a web server to a browser.

        static byte[] GetBytes(string value)
        {
            byte[] bytes = null;
            using (var memoryStream = new MemoryStream())
            {
                using (var streamWriter = new StreamWriter(memoryStream, Encoding.Default))
                {
                    streamWriter.Write(value);

                    streamWriter.Flush();
                    streamWriter.Close();

                    bytes = memoryStream.ToArray();
                }
            }

            return bytes;

        }

But this solution also uses the Encoding.Default for the StreamWriter.

The Enconding can also be performed as:

string sample = "This is a simple string";
byte[] content = Encoding.Default.GetBytes(sample);

Welcome the the encondig hell!!