System.Text Namespace
 

The System.Text namespace contains classes that represent ASCII and Unicode character encodings; abstract base classes for converting blocks of characters to and from blocks of bytes; and a helper class that manipulates and formats String objects without creating intermediate instances of String.

ClassDescription
System_CAPS_pubclass ASCIIEncoding

Represents an ASCII character encoding of Unicode characters.

System_CAPS_pubclass Decoder

Converts a sequence of encoded bytes into a set of characters.

System_CAPS_pubclass DecoderExceptionFallback

Provides a failure-handling mechanism, called a fallback, for an encoded input byte sequence that cannot be converted to an input character. The fallback throws an exception instead of decoding the input byte sequence. This class cannot be inherited.

System_CAPS_pubclass DecoderExceptionFallbackBuffer

Throws DecoderFallbackException when an encoded input byte sequence cannot be converted to a decoded output character. This class cannot be inherited.

System_CAPS_pubclass DecoderFallback

Provides a failure-handling mechanism, called a fallback, for an encoded input byte sequence that cannot be converted to an output character.

System_CAPS_pubclass DecoderFallbackBuffer

Provides a buffer that allows a fallback handler to return an alternate string to a decoder when it cannot decode an input byte sequence.

System_CAPS_pubclass DecoderFallbackException

The exception that is thrown when a decoder fallback operation fails. This class cannot be inherited.

System_CAPS_pubclass DecoderReplacementFallback

Provides a failure-handling mechanism, called a fallback, for an encoded input byte sequence that cannot be converted to an output character. The fallback emits a user-specified replacement string instead of a decoded input byte sequence. This class cannot be inherited.

System_CAPS_pubclass DecoderReplacementFallbackBuffer

Represents a substitute output string that is emitted when the original input byte sequence cannot be decoded. This class cannot be inherited.

System_CAPS_pubclass Encoder

Converts a set of characters into a sequence of bytes.

System_CAPS_pubclass EncoderExceptionFallback

Provides a failure-handling mechanism, called a fallback, for an input character that cannot be converted to an output byte sequence. The fallback throws an exception if an input character cannot be converted to an output byte sequence. This class cannot be inherited.

System_CAPS_pubclass EncoderExceptionFallbackBuffer

Throws EncoderFallbackException when an input character cannot be converted to an encoded output byte sequence. This class cannot be inherited.

System_CAPS_pubclass EncoderFallback

Provides a failure-handling mechanism, called a fallback, for an input character that cannot be converted to an encoded output byte sequence.

System_CAPS_pubclass EncoderFallbackBuffer

Provides a buffer that allows a fallback handler to return an alternate string to an encoder when it cannot encode an input character.

System_CAPS_pubclass EncoderFallbackException

The exception that is thrown when an encoder fallback operation fails. This class cannot be inherited.

System_CAPS_pubclass EncoderReplacementFallback

Provides a failure handling mechanism, called a fallback, for an input character that cannot be converted to an output byte sequence. The fallback uses a user-specified replacement string instead of the original input character. This class cannot be inherited.

System_CAPS_pubclass EncoderReplacementFallbackBuffer

Represents a substitute input string that is used when the original input character cannot be encoded. This class cannot be inherited.

System_CAPS_pubclass Encoding

Represents a character encoding.

To browse the .NET Framework source code for this type, see the Reference Source.

System_CAPS_pubclass EncodingInfo

Provides basic information about an encoding.

System_CAPS_pubclass EncodingProvider

Provides the base class for an encoding provider, which supplies encodings that are unavailable on a particular platform.

System_CAPS_pubclass StringBuilder

Represents a mutable string of characters. This class cannot be inherited.

To browse the .NET Framework source code for this type, see the Reference Source.

System_CAPS_pubclass UnicodeEncoding

Represents a UTF-16 encoding of Unicode characters.

System_CAPS_pubclass UTF32Encoding

Represents a UTF-32 encoding of Unicode characters.

System_CAPS_pubclass UTF7Encoding

Represents a UTF-7 encoding of Unicode characters.

System_CAPS_pubclass UTF8Encoding

Represents a UTF-8 encoding of Unicode characters.

EnumerationDescription
System_CAPS_pubenum NormalizationForm

Defines the type of normalization to perform.

The encoding classes are primarily intended to convert between different encodings or code pages and a Unicode encoding. (UTF-16) encoding is used internally by the .NET Framework, and encoding is often used for storing character data to ensure portability across machines and cultures.

The classes derived from Encoding enable you to choose a fallback strategy, which determines how characters that cannot be encoded into a sequence of bytes, or bytes that cannot be decoded into characters, are handled. You can choose one of the following:

  • Exception fallback. You can choose to throw exceptions on data errors either by using a throwonerror flag that is available in some class constructors or by using the EncoderExceptionFallback and DecoderExceptionFallback classes. If you are concerned about the integrity of the data stream, throwing on an exception is recommended.

  • Replacement fallback. You can use the EncoderFallback and DecoderFallback classes to silently change a character to "?" or to the Unicode replacement character (U+FFFD).

  • Best-fit fallback. This option maps a character in one encoding to a character in another encoding. Best fit fallback is often not recommended because it can cause data loss and confusion, and is slower than simple "?" character replacements. However, for ANSI code pages the best-fit behavior is the default.

The StringBuilder class is designed for operations that perform extensive manipulations on a single string. Unlike the String class, the StringBuilder class is mutable and provides better performance when concatenating or deleting strings.

For more information about System.Text, see Character Encoding in the .NET Framework .

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