You have a byte[]
,
which could represent some binary information such as a bitmap. You
need to encode this data into a string so that it can be sent over a
binary-unfriendly transport such as email.
Using the static method
Convert
.ToBase64CharArray
on
the Convert
class, a byte[]
may
be encoded to a char[]
equivalent, and the
char[]
can then be converted to a
string
:
using System; public static string Base64EncodeBytes(byte[] inputBytes) { // Each 3-byte sequence in inputBytes must be converted to a 4-byte // sequence long arrLength = (long)(4.0d * inputBytes.Length / 3.0d); if ((arrLength % 4) != 0) { // increment the array length to the next multiple of 4 // if it is not already divisible by 4 arrLength += 4 - (arrLength % 4); } char[] encodedCharArray = new char[arrLength]; Convert.ToBase64CharArray(inputBytes, 0, inputBytes.Length, encodedCharArray, 0); return (new string(encodedCharArray)); }
The Convert
class makes encoding between a
byte[]
and a char[]
and/or a
string
a simple matter. The
ToBase64CharArray
method fills the specified
character array with converted bytes, and also returns an integer
specifying the number of elements in the resulting
byte[]
, which, in this recipe, is discarded. As
you can see, the parameters for this method are quite flexible. It
provides the ability to start and stop the conversion at any point in
the input byte array and to add elements starting at any position in
the resulting char[]
.
To encode a bitmap file into a string that can be sent to some destination via email, you could use the following code:
FileStream fstrm = new FileStream(@"C:WINNTwinnt.bmp", FileMode.Open, FileAccess.Read); BinaryReader reader = new BinaryReader(fstrm); byte[] image = new byte[reader.BaseStream.Length]; for (int i = 0; i < reader.BaseStream.Length; i++) { image[i] = reader.ReadByte( ); } reader.Close( ); fstrm.Close( ); string bmpAsString = Base64EncodeBytes(image);
The bmpAsString
string can then be sent as the
body of an email message.
To decode an encoded string to a byte[]
, see
Recipe 2.12.
See Recipe 2.12; see the “Convert.ToBase64CharArray Method” topic in the MSDN documentation.