2.11. Encoding Binary Data as Base64
Problem
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.
Solution
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)); }
Discussion
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 ...
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