How do I get a consistent byte representation of strings in C# without manually specifying an encoding?

Question

How do I convert a string to a byte[] in .NET (C#) without manually specifying a specific encoding?

I'm going to encrypt the string. I can encrypt it without converting, but I'd still like to know why encoding comes to play here.

Also, why should encoding even be taken into consideration? Can't I simply get what bytes the string has been stored in? Why is there a dependency on character encodings?

Answer 1

bytes[] buffer = UnicodeEncoding.UTF8.GetBytes(string something); //for converting to UTF then get its bytes

bytes[] buffer = ASCIIEncoding.ASCII.GetBytes(string something); //for converting to ascii then get its bytes

Answer 2

simple code with LINQ

string s = "abc"
byte[] b = s.Select(e => (byte)e).ToArray();

EDIT : as commented below, it is not a good way.

but you can still use it to understand LINQ with a more appropriate coding :

string s = "abc"
byte[] b = s.Cast<byte>().ToArray();

Answer 3

Simply use this:

byte[] myByte= System.Text.ASCIIEncoding.Default.GetBytes(myString);

Answer 4

I have written a Visual Basic extension similar to the accepted answer, but directly using .NET memory and Marshalling for conversion, and it supports character ranges unsupported in other methods, like UnicodeEncoding.UTF8.GetString or UnicodeEncoding.UTF32.GetString or even MemoryStream and BinaryFormatter (invalid characters like: 񩱠 & ChrW(55906) & ChrW(55655)):

<Extension> _
Public Function ToBytesMarshal(ByRef str As String) As Byte()
    Dim gch As GCHandle = GCHandle.Alloc(str, GCHandleType.Pinned)
    Dim handle As IntPtr = gch.AddrOfPinnedObject
    ToBytesMarshal = New Byte(str.Length * 2 - 1) {}
    Try
        For i As Integer = 0 To ToBytesMarshal.Length - 1
            ToBytesMarshal.SetValue(Marshal.ReadByte(IntPtr.Add(handle, i)), i)
        Next
    Finally
        gch.Free()
    End Try
End Function

<Extension> _
Public Function ToStringMarshal(ByRef arr As Byte()) As String
    Dim gch As GCHandle = GCHandle.Alloc(arr, GCHandleType.Pinned)
    Try
        ToStringMarshal = Marshal.PtrToStringAuto(gch.AddrOfPinnedObject)
    Finally
        gch.Free()
    End Try
End Function

Answer 5

A character is both a lookup key into a font table and a lexical tradition such as ordering, upper and lower case versions, etc.

Consequently, a character is not a byte (8-bits) and a byte is not a character. In particular, the 256 permutations of a byte cannot accommodate the thousands of symbols within some written languages, much less all languages. Hence, various methods for encoding characters have been devised. Some encode for a particular class of languages (ASCII encoding); multiple languages using code pages (Extended ASCII); or, ambitiously, all languages by selectively including additional bytes as needed, Unicode.

Within a system, such as the .NET framework, a String implies a particular character encoding. In .NET this encoding is Unicode. Since the framework reads and writes Unicode by default, dealing with character encoding is typically not necessary in .NET.

However, in general, to load a character string into the system from a byte stream you need to know the source encoding to therefore interpret and subsequently translate it correctly (otherwise the codes will be taken as already being in the system's default encoding and thus render gibberish). Similarly, when a string is written to an external source, it will be written in a particular encoding.

Answer 6

From byte[] to string:

        return BitConverter.ToString(bytes);

Answer 7

To convert a string to a byte[] use the following solution:

string s = "abcdefghijklmnopqrstuvwxyz";
byte[] b = System.Text.UTF32Encoding.GetBytes(s);

I hope it helps.

Answer 8

// C# to convert a string to a byte array.
public static byte[] StrToByteArray(string str)
{
    System.Text.ASCIIEncoding  encoding=new System.Text.ASCIIEncoding();
    return encoding.GetBytes(str);
}


// C# to convert a byte array to a string.
byte [] dBytes = ...
string str;
System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
str = enc.GetString(dBytes);

Answer 9

Here is the code:

// Input string.
const string input = "Dot Net Perls";

// Invoke GetBytes method.
// ... You can store this array as a field!
byte[] array = Encoding.ASCII.GetBytes(input);

// Loop through contents of the array.
foreach (byte element in array)
{
    Console.WriteLine("{0} = {1}", element, (char)element);
}

Answer 10

I had to convert a string to a byte array for a serial communication project - I had to handle 8-bit characters, and I was unable to find a method using the framework converters to do so that didn't either add two-byte entries or mis-translate the bytes with the eighth bit set. So I did the following, which works:

string message = "This is a message.";
byte[] bytes = new byte[message.Length];
for (int i = 0; i < message.Length; i++)
    bytes[i] = (byte)message[i];

Answer 11

OP's question: "How do I convert a string to a byte array in .NET (C#)?" [sic]

You can use the following code:

static byte[] ConvertString (string s) {
    return new byte[0];
}

As a benefit, encoding does not matter! Oh wait, this is an ecoding... it's just trivial and highly lossy.