When overridden in a derived class, returns a sequence of bytes that specifies the encoding used.
Assembly: mscorlib (in mscorlib.dll)
Optionally, the Encoding object provides a preamble that is an array of bytes that can be prefixed to the sequence of bytes resulting from the encoding process. If the preamble contains a byte order mark (in Unicode, code point U+FEFF), it helps the decoder determine the byte order and the transformation format or UTF.
The Unicode byte order mark (BOM) is serialized as follows (in hexadecimal):
UTF-8: EF BB BF
UTF-16 big-endian byte order: FE FF
UTF-16 little-endian byte order: FF FE
To ensure that the encoded bytes are decoded properly, your application should prefix encoded bytes with a preamble. However, most encodings do not provide a preamble. To ensure that the encoded bytes are decoded properly, the application should use the UTF8Encoding or UnicodeEncoding Unicode encodings with a preamble.
The following code example determines the byte order of the encoding based on the preamble.
Imports System.Text Class Example Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) Dim [unicode] As Encoding = Encoding.Unicode ' Get the preamble for the Unicode encoder. ' In this case the preamble contains the byte order mark (BOM). Dim preamble As Byte() = [unicode].GetPreamble() ' Make sure a preamble was returned ' and is large enough to contain a BOM. If preamble.Length >= 2 Then If preamble(0) = &HFE And preamble(1) = &HFF Then outputBlock.Text &= "The Unicode encoder is encoding in big-endian order." & vbCrLf Else If preamble(0) = &HFF And preamble(1) = &HFE Then outputBlock.Text &= "The Unicode encoder is encoding in little-endian order." & vbCrLf End If End If End If End Sub End Class
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.