Recipe 2.13 Converting a String Returned as a Byte[ ] Back into a String

Problem

Many methods in the FCL return a byte[] consisting of characters instead of a string. Some of these methods include:

System.Net.Sockets.Socket.Receive
System.Net.Sockets.Socket.ReceiveFrom
System.Net.Sockets.Socket.BeginReceive
System.Net.Sockets.Socket.BeginReceiveFrom
System.Net.Sockets.NetworkStream.Read
System.Net.Sockets.NetworkStream.BeginRead
System.IO.BinaryReader.Read
System.IO.BinaryReader.ReadBytes
System.IO.FileStream.Read
System.IO.FileStream.BeginRead
System.IO.MemoryStream // Constructor
System.IO.MemoryStream.Read
System.IO.MemoryStream.BeginRead
System.Security.Cryptography.CryptoStream.Read
System.Security.Cryptography.CryptoStream.BeginRead
System.Diagnostics.EventLogEntry.Data

In many cases, this byte[] might contain ASCII or Unicode encoded characters. You need a way to recombine this byte[] to obtain the original string.

Solution

To convert a byte array of ASCII values to a complete string, use the following method:

using System;
using System.Text;

public static string FromASCIIByteArray(byte[] characters)
{
    ASCIIEncoding encoding = new ASCIIEncoding( );
    string constructedString = encoding.GetString(characters);

    return (constructedString);
}

To convert a byte array of Unicode values (UTF-16 encoded) to a complete string, use the following method:

public static string FromUnicodeByteArray(byte[] characters)
{
    UnicodeEncoding encoding = new UnicodeEncoding( );
    string constructedString = encoding.GetString(characters);

    return (constructedString);
}

Discussion

The GetString method of the ASCIIEncoding class converts 7-bit ASCII characters contained in a byte array to a string. Any value larger than 127 is converted to the ? character. The ASCIIEncoding class can be found in the System.Text namespace. The GetString method is overloaded to accept additional arguments as well. The overloaded versions of the method convert all or part of a string to ASCII and then store the result in a specified range inside a byte array.

The GetString method returns a string containing the converted byte array of ASCII characters.

The GetString method of the UnicodeEncoding class converts Unicode characters into 16-bit Unicode values. The UnicodeEncoding class can be found in the System.Text namespace. The GetString method returns a string containing the converted byte array of Unicode characters.

See Also

See the "ASCIIEncoding Class" and "UnicodeEncoding Class" topics in the MSDN documentation.