UTF7Encoding.GetBytes Method (String, Int32, Int32, Byte(), Int32)

 

Encodes a set of characters from the specified String into the specified byte array.

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

<ComVisibleAttribute(False)>
Public Overrides Function GetBytes (
	s As String,
	charIndex As Integer,
	charCount As Integer,
	bytes As Byte(),
	byteIndex As Integer
) As Integer

Parameters

s
Type: System.String

The String containing the set of characters to encode.

charIndex
Type: System.Int32

The index of the first character to encode.

charCount
Type: System.Int32

The number of characters to encode.

bytes
Type: System.Byte()

The byte array to contain the resulting sequence of bytes.

byteIndex
Type: System.Int32

The index at which to start writing the resulting sequence of bytes.

Return Value

Type: System.Int32

The actual number of bytes written into bytes.

Exception Condition
ArgumentNullException

s is null (Nothing).

-or-

bytes is null (Nothing).

ArgumentOutOfRangeException

charIndex or charCount or byteIndex is less than zero.

-or-

charIndex and charCount do not denote a valid range in chars.

-or-

byteIndex is not a valid index in bytes.

ArgumentException

bytes does not have enough capacity from byteIndex to the end of the array to accommodate the resulting bytes.

EncoderFallbackException

A fallback occurred (see Character Encoding in the .NET Framework for fuller explanation)

-and-

EncoderFallback is set to EncoderExceptionFallback.

To calculate the exact array size required by GetBytes to store the resulting bytes, the application uses GetByteCount. To calculate the maximum array size, the application should use GetMaxByteCount. The GetByteCount method generally allows allocation of less memory, while the GetMaxByteCount method generally executes faster.

Data to be converted, such as data read from a stream, might be available only in sequential blocks. In this case, or if the amount of data is so large that it needs to be divided into smaller blocks, the application should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively.

System_CAPS_noteNote

UTF7Encoding does not provide error detection. Invalid characters are encoded as a modified base 64 character. For security reasons, your applications are recommended to use UTF8Encoding, UnicodeEncoding, or UTF32Encoding and enable error detection.

The following code example demonstrates how to use the GetBytes method to encode a range of elements from a Unicode character array, and store the encoded bytes in a range of elements in a byte array.

Imports System
Imports System.Text
Imports Microsoft.VisualBasic.strings

Class UTF7EncodingExample

    Public Shared Sub Main()
        Dim bytes() As Byte
        ' Unicode characters.
        ' ChrW(35)  = #
        ' ChrW(37)  = %
        ' ChrW(928) = Pi
        ' ChrW(931) = Sigma
        Dim chars() As Char = {ChrW(35), ChrW(37), ChrW(928), ChrW(931)}

        Dim utf7 As New UTF7Encoding()

        Dim byteCount As Integer = utf7.GetByteCount(chars, 1, 2)
        bytes = New Byte(byteCount - 1) {}
        Dim bytesEncodedCount As Integer = utf7.GetBytes(chars, 1, 2, bytes, 0)

        Console.WriteLine("{0} bytes used to encode characters.", bytesEncodedCount)

        Console.Write("Encoded bytes: ")
        Dim b As Byte
        For Each b In  bytes
            Console.Write("[{0}]", b)
        Next b
        Console.WriteLine()
    End Sub 'Main
End Class 'UTF7EncodingExample

Universal Windows Platform
Available since 10
.NET Framework
Available since 2.0
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