Convert.ToBase64String Method (Byte[], Int32, Int32)


Converts a subset of an array of 8-bit unsigned integers to its equivalent string representation that is encoded with base-64 digits. Parameters specify the subset as an offset in the input array, and the number of elements in the array to convert.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public static string ToBase64String(
	byte[] inArray,
	int offset,
	int length


Type: System.Byte[]

An array of 8-bit unsigned integers.

Type: System.Int32

An offset in inArray.

Type: System.Int32

The number of elements of inArray to convert.

Return Value

Type: System.String

The string representation in base 64 of length elements of inArray, starting at position offset.

Exception Condition

inArray is null.


offset or length is negative.


offset plus length is greater than the length of inArray.

The elements of inArray are taken as a numeric value and converted to a string representation in base 64.

The base-64 digits in ascending order from zero are the uppercase characters "A" to "Z", the lowercase characters "a" to "z", the numerals "0" to "9", and the symbols "+" and "/". The valueless character, "=", is used for trailing padding.

The offset and length parameters are 32-bit signed numbers. The offset parameter is zero-based.


The ToBase64String method is designed to process a single byte array that contains all the data to be encoded. To encode data from a stream, use the System.Security.Cryptography.ToBase64Transform class.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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