Represents a character encoding.
See Also: Encoding Members
Syntax
public abstract class Encoding : ICloneable
Remarks
Encoding is the process of transforming a set of Unicode characters into a sequence of bytes. In contrast, decoding is the process of transforming a sequence of encoded bytes into a set of Unicode characters. For information about the Unicode Transformation Formats (UTFs) and other encodings supported by System.Text.Encoding, see Understanding Encodings.
Note that System.Text.Encoding is intended to operate on Unicode characters instead of arbitrary binary data, such as byte arrays. If your application must encode arbitrary binary data into text, it should use a protocol such as uuencode, which is implemented by methods such as Convert.ToBase64CharArray(Byte[], int, int, Char[], int).
The .NET Framework provides the following implementations of the System.Text.Encoding class to support current Unicode encodings and other encodings:
System.Text.ASCIIEncoding encodes Unicode characters as single 7-bit ASCII characters. This encoding only supports character values between U+0000 and U+007F. Code page 20127. Also available through the Encoding.ASCII property.
System.Text.UTF7Encoding encodes Unicode characters using the UTF-7 encoding. This encoding supports all Unicode character values. Code page 65000. Also available through the Encoding.UTF7 property.
System.Text.UTF8Encoding encodes Unicode characters using the UTF-8 encoding. This encoding supports all Unicode character values. Code page 65001. Also available through the Encoding.UTF8 property.
System.Text.UnicodeEncoding encodes Unicode characters using the UTF-16 encoding. Both little endian and big endian byte orders are supported. Also available through the Encoding.Unicode property and the Encoding.BigEndianUnicode property.
System.Text.UTF32Encoding encodes Unicode characters using the UTF-32 encoding. Both little endian (code page 12000) and big endian (code page 12001) byte orders are supported. Also available through the Encoding.UTF32 property.
The System.Text.Encoding class is primarily intended to convert between different encodings and Unicode. Often one of the derived Unicode classes is the correct choice for your application.
You use the Encoding.GetEncoding(int) method to obtain other encodings. You can call the Encoding.GetEncodings method to get a list of all encodings.
The following table lists the encodings supported by the .NET Framework. It lists each encoding's code page number, along with the values of the encoding's EncodingInfo.Name and EncodingInfo.DisplayName properties. . An asterisk in the last column indicates that the code page is natively supported by the .NET Framework, regardless of the underlying platform. Note that code pages whose EncodingInfo.Name property corresponds to an international standard do not necessarily comply in full with that standard.
| 37 |
IBM037 |
IBM EBCDIC (US-Canada) |
|
| 437 |
IBM437 |
OEM United States |
|
| 500 |
IBM500 |
IBM EBCDIC (International) |
|
| 708 |
ASMO-708 |
Arabic (ASMO 708) |
|
| 720 |
DOS-720 |
Arabic (DOS) |
|
| 737 |
ibm737 |
Greek (DOS) |
|
| 775 |
ibm775 |
Baltic (DOS) |
|
| 850 |
ibm850 |
Western European (DOS) |
|
| 852 |
ibm852 |
Central European (DOS) |
|
| 855 |
IBM855 |
OEM Cyrillic |
|
| 857 |
ibm857 |
Turkish (DOS) |
|
| 858 |
IBM00858 |
OEM Multilingual Latin I |
|
| 860 |
IBM860 |
Portuguese (DOS) |
|
| 861 |
ibm861 |
Icelandic (DOS) |
|
| 862 |
DOS-862 |
Hebrew (DOS) |
|
| 863 |
IBM863 |
French Canadian (DOS) |
|
| 864 |
IBM864 |
Arabic (864) |
|
| 865 |
IBM865 |
Nordic (DOS) |
|
| 866 |
cp866 |
Cyrillic (DOS) |
|
| 869 |
ibm869 |
Greek, Modern (DOS) |
|
| 870 |
IBM870 |
IBM EBCDIC (Multilingual Latin-2) |
|
| 874 |
windows-874 |
Thai (Windows) |
|
| 875 |
cp875 |
IBM EBCDIC (Greek Modern) |
|
| 932 |
shift_jis |
Japanese (Shift-JIS) |
|
| 936 |
gb2312 |
Chinese Simplified (GB2312) |
* |
| 949 |
ks_c_5601-1987 |
Korean |
|
| 950 |
big5 |
Chinese Traditional (Big5) |
|
| 1026 |
IBM1026 |
IBM EBCDIC (Turkish Latin-5) |
|
| 1047 |
IBM01047 |
IBM Latin-1 |
|
| 1140 |
IBM01140 |
IBM EBCDIC (US-Canada-Euro) |
|
| 1141 |
IBM01141 |
IBM EBCDIC (Germany-Euro) |
|
| 1142 |
IBM01142 |
IBM EBCDIC (Denmark-Norway-Euro) |
|
| 1143 |
IBM01143 |
IBM EBCDIC (Finland-Sweden-Euro) |
|
| 1144 |
IBM01144 |
IBM EBCDIC (Italy-Euro) |
|
| 1145 |
IBM01145 |
IBM EBCDIC (Spain-Euro) |
|
| 1146 |
IBM01146 |
IBM EBCDIC (UK-Euro) |
|
| 1147 |
IBM01147 |
IBM EBCDIC (France-Euro) |
|
| 1148 |
IBM01148 |
IBM EBCDIC (International-Euro) |
|
| 1149 |
IBM01149 |
IBM EBCDIC (Icelandic-Euro) |
|
| 1200 |
utf-16 |
Unicode |
* |
| 1201 |
unicodeFFFE |
Unicode (Big endian) |
* |
| 1250 |
windows-1250 |
Central European (Windows) |
|
| 1251 |
windows-1251 |
Cyrillic (Windows) |
|
| 1252 |
Windows-1252 |
Western European (Windows) |
* |
| 1253 |
windows-1253 |
Greek (Windows) |
|
| 1254 |
windows-1254 |
Turkish (Windows) |
|
| 1255 |
windows-1255 |
Hebrew (Windows) |
|
| 1256 |
windows-1256 |
Arabic (Windows) |
|
| 1257 |
windows-1257 |
Baltic (Windows) |
|
| 1258 |
windows-1258 |
Vietnamese (Windows) |
|
| 1361 |
Johab |
Korean (Johab) |
|
| 10000 |
macintosh |
Western European (Mac) |
|
| 10001 |
x-mac-japanese |
Japanese (Mac) |
|
| 10002 |
x-mac-chinesetrad |
Chinese Traditional (Mac) |
|
| 10003 |
x-mac-korean |
Korean (Mac) |
* |
| 10004 |
x-mac-arabic |
Arabic (Mac) |
|
| 10005 |
x-mac-hebrew |
Hebrew (Mac) |
|
| 10006 |
x-mac-greek |
Greek (Mac) |
|
| 10007 |
x-mac-cyrillic |
Cyrillic (Mac) |
|
| 10008 |
x-mac-chinesesimp |
Chinese Simplified (Mac) |
* |
| 10010 |
x-mac-romanian |
Romanian (Mac) |
|
| 10017 |
x-mac-ukrainian |
Ukrainian (Mac) |
|
| 10021 |
x-mac-thai |
Thai (Mac) |
|
| 10029 |
x-mac-ce |
Central European (Mac) |
|
| 10079 |
x-mac-icelandic |
Icelandic (Mac) |
|
| 10081 |
x-mac-turkish |
Turkish (Mac) |
|
| 10082 |
x-mac-croatian |
Croatian (Mac) |
|
| 12000 |
utf-32 |
Unicode (UTF-32) |
* |
| 12001 |
utf-32BE |
Unicode (UTF-32 Big endian) |
* |
| 20000 |
x-Chinese-CNS |
Chinese Traditional (CNS) |
|
| 20001 |
x-cp20001 |
TCA Taiwan |
|
| 20002 |
x-Chinese-Eten |
Chinese Traditional (Eten) |
|
| 20003 |
x-cp20003 |
IBM5550 Taiwan |
|
| 20004 |
x-cp20004 |
TeleText Taiwan |
|
| 20005 |
x-cp20005 |
Wang Taiwan |
|
| 20105 |
x-IA5 |
Western European (IA5) |
|
| 20106 |
x-IA5-German |
German (IA5) |
|
| 20107 |
x-IA5-Swedish |
Swedish (IA5) |
|
| 20108 |
x-IA5-Norwegian |
Norwegian (IA5) |
|
| 20127 |
us-ascii |
US-ASCII |
* |
| 20261 |
x-cp20261 |
T.61 |
|
| 20269 |
x-cp20269 |
ISO-6937 |
|
| 20273 |
IBM273 |
IBM EBCDIC (Germany) |
|
| 20277 |
IBM277 |
IBM EBCDIC (Denmark-Norway) |
|
| 20278 |
IBM278 |
IBM EBCDIC (Finland-Sweden) |
|
| 20280 |
IBM280 |
IBM EBCDIC (Italy) |
|
| 20284 |
IBM284 |
IBM EBCDIC (Spain) |
|
| 20285 |
IBM285 |
IBM EBCDIC (UK) |
|
| 20290 |
IBM290 |
IBM EBCDIC (Japanese katakana) |
|
| 20297 |
IBM297 |
IBM EBCDIC (France) |
|
| 20420 |
IBM420 |
IBM EBCDIC (Arabic) |
|
| 20423 |
IBM423 |
IBM EBCDIC (Greek) |
|
| 20424 |
IBM424 |
IBM EBCDIC (Hebrew) |
|
| 20833 |
x-EBCDIC-KoreanExtended |
IBM EBCDIC (Korean Extended) |
|
| 20838 |
IBM-Thai |
IBM EBCDIC (Thai) |
|
| 20866 |
koi8-r |
Cyrillic (KOI8-R) |
|
| 20871 |
IBM871 |
IBM EBCDIC (Icelandic) |
|
| 20880 |
IBM880 |
IBM EBCDIC (Cyrillic Russian) |
|
| 20905 |
IBM905 |
IBM EBCDIC (Turkish) |
|
| 20924 |
IBM00924 |
IBM Latin-1 |
|
| 20932 |
EUC-JP |
Japanese (JIS 0208-1990 and 0212-1990) |
|
| 20936 |
x-cp20936 |
Chinese Simplified (GB2312-80) |
* |
| 20949 |
x-cp20949 |
Korean Wansung |
* |
| 21025 |
cp1025 |
IBM EBCDIC (Cyrillic Serbian-Bulgarian) |
|
| 21866 |
koi8-u |
Cyrillic (KOI8-U) |
|
| 28591 |
iso-8859-1 |
Western European (ISO) |
* |
| 28592 |
iso-8859-2 |
Central European (ISO) |
|
| 28593 |
iso-8859-3 |
Latin 3 (ISO) |
|
| 28594 |
iso-8859-4 |
Baltic (ISO) |
|
| 28595 |
iso-8859-5 |
Cyrillic (ISO) |
|
| 28596 |
iso-8859-6 |
Arabic (ISO) |
|
| 28597 |
iso-8859-7 |
Greek (ISO) |
|
| 28598 |
iso-8859-8 |
Hebrew (ISO-Visual) |
* |
| 28599 |
iso-8859-9 |
Turkish (ISO) |
|
| 28603 |
iso-8859-13 |
Estonian (ISO) |
|
| 28605 |
iso-8859-15 |
Latin 9 (ISO) |
|
| 29001 |
x-Europa |
Europa |
|
| 38598 |
iso-8859-8-i |
Hebrew (ISO-Logical) |
* |
| 50220 |
iso-2022-jp |
Japanese (JIS) |
* |
| 50221 |
csISO2022JP |
Japanese (JIS-Allow 1 byte Kana) |
* |
| 50222 |
iso-2022-jp |
Japanese (JIS-Allow 1 byte Kana - SO/SI) |
* |
| 50225 |
iso-2022-kr |
Korean (ISO) |
* |
| 50227 |
x-cp50227 |
Chinese Simplified (ISO-2022) |
* |
| 51932 |
euc-jp |
Japanese (EUC) |
* |
| 51936 |
EUC-CN |
Chinese Simplified (EUC) |
* |
| 51949 |
euc-kr |
Korean (EUC) |
* |
| 52936 |
hz-gb-2312 |
Chinese Simplified (HZ) |
* |
| 54936 |
GB18030 |
Chinese Simplified (GB18030) |
* |
| 57002 |
x-iscii-de |
ISCII Devanagari |
* |
| 57003 |
x-iscii-be |
ISCII Bengali |
* |
| 57004 |
x-iscii-ta |
ISCII Tamil |
* |
| 57005 |
x-iscii-te |
ISCII Telugu |
* |
| 57006 |
x-iscii-as |
ISCII Assamese |
* |
| 57007 |
x-iscii-or |
ISCII Oriya |
* |
| 57008 |
x-iscii-ka |
ISCII Kannada |
* |
| 57009 |
x-iscii-ma |
ISCII Malayalam |
* |
| 57010 |
x-iscii-gu |
ISCII Gujarati |
* |
| 57011 |
x-iscii-pa |
ISCII Punjabi |
* |
| 65000 |
utf-7 |
Unicode (UTF-7) |
* |
| 65001 |
utf-8 |
Unicode (UTF-8) |
* |
If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, your application should use the System.Text.Decoder or the System.Text.Encoder provided by the Encoding.GetDecoder method or the Encoding.GetEncoder method, respectively, of a derived class.
The UTF-16 and the UTF-32 encoders can use the big endian byte order (most significant byte first) or the little endian byte order (least significant byte first). For example, the Latin Capital Letter A (U+0041) is serialized as follows (in hexadecimal):
UTF-16 big endian byte order: 00 41
UTF-16 little endian byte order: 41 00
UTF-32 big endian byte order: 00 00 00 41
UTF-32 little endian byte order: 41 00 00 00
It is generally more efficient to store Unicode characters using the native byte order. For example, it is better to use the little endian byte order on little endian platforms, such as Intel computers.
The Encoding.GetPreamble method retrieves an array of bytes that includes the byte order mark (BOM). If this byte array is prefixed to an encoded stream, it helps the decoder to identify the encoding format used.
For more information on byte order and the byte order mark, see The Unicode Standard at the tp://go.microsoft.com/fwlink/?LinkId=37123.
Note that the encoding classes allow errors to:
Silently change to a "?" character.
Use a "best fit" character.
Change to an application-specific behavior through use of the System.Text.EncoderFallback and System.Text.DecoderFallback classes with the U+FFFD Unicode replacement character.
Your applications are recommended to throw exceptions on all data stream errors. An application either uses a "throwonerror" flag when applicable or uses the System.Text.EncoderExceptionFallback and System.Text.DecoderExceptionFallback classes. Best fit fallback is often not recommended because it can cause data loss or confusion and is slower than simple character replacements. For ANSI encodings, the best fit behavior is the default.
Thread Safety
Requirements
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0