TEncoding¶

Encoding support.

Declaration¶

Source position: sysencodingh.inc line 27

type

  TEncoding = class
  public
    function Clone : TEncoding;
    class function Convert(Source: TEncoding; Destination: TEncoding; 
                      const Bytes: TBytes) : TBytes; overload;
    class function Convert(Source: TEncoding; Destination: TEncoding; 
                      const Bytes: TBytes; StartIndex: Integer; 
                      Count: Integer) : TBytes; overload;
    class function IsStandardEncoding : Boolean;
    class function GetBufferEncoding(const Buffer: TBytes; 
                                var AEncoding: TEncoding) : Integer; overload;
    class function GetBufferEncoding(const Buffer: TBytes; 
                                var AEncoding: TEncoding; 
                                ADefaultEncoding: TEncoding) : Integer; overload;
    class function GetEncoding(CodePage: Integer) : TEncoding; overload;
    class function GetEncoding(const EncodingName: UnicodeString)
                           : TEncoding; overload;
    function GetMaxByteCount : Integer;
    function GetMaxCharCount : Integer;
    function GetPreamble : TBytes;
    function GetString(const Bytes: TBytes) : UnicodeString; overload;
    function GetString(const Bytes: TBytes; ByteIndex: Integer; 
                  ByteCount: Integer) : UnicodeString; overload;
    property CodePage: Cardinal; {r}
    property EncodingName: UnicodeString; {r}
    property IsSingleByte: Boolean; {r}
    class property ANSI: TEncoding; {r}
    class property ASCII: TEncoding; {r}
    class property BigEndianUnicode: TEncoding; {r}
    class property Default: TEncoding; {r}
    class property SystemEncoding: TEncoding; {r}
    class property Unicode: TEncoding; {r}
    class property UTF7: TEncoding; {r}
    class property UTF8: TEncoding; {r}
  end;

Inheritance¶

Description¶

TEncoding is a mostly abstract class that contains various methods to deal with different encodings in single- and double-byte strings. In practice, one instance of a descendent of this class for each needed encoding can be instantiated and used. The class contains several class methods and properties to create such instances, and has several often-used instances available as class properties, in particular the default encoding.

When using encodings (and in particular TEncoding.Default or TEncoding.ANSI), if the DefaultSystemCodePage changes, you should call TEncoding.FreeEncodings to regenerate the encodings.

Properties¶

Member	Visibility	Description
ANSI read only	public	Ansi encoding instance.
ASCII read only	public	ASCII encoding instance.
BigEndianUnicode read only	public	Big-endian Unicode (UTF16BE) encoding instance.
CodePage read only	public	Codepage for this encoding.
Default read only	public	Default codepage.
EncodingName read only	public	Name of this encoding.
IsSingleByte read only	public	Is the encoding a single-byte encoding or not ?
SystemEncoding read only	public	System encoding.
Unicode read only	public	UTF16 encoding instance.
UTF7 read only	public	UTF7 encoding instance.
UTF8 read only	public	UTF8 encoding instance.

Methods¶

Member	Visibility	Description
Clone	public	Clone a TEncoding instance.
Convert	public	Convert an array of bytes from one encoding to another.
GetBufferEncoding	public	Attempt to guess the encoding of a buffer.
GetEncoding	public	Get an encoding instance for a given codepage.
GetMaxByteCount	public	Returns the maximum number of bytes needed to represent a string.
GetMaxCharCount	public	Return the maximum number of characters that can be represented in a number of bytes.
GetPreamble	public	Return the BOM Marker used by the encoding.
GetString	public	Return a string based on an array of bytes.
IsStandardEncoding	public	Check if the encoding is one of the standard encodings.

Name	Description
TEncoding.ANSI	Ansi encoding instance.
TEncoding.ASCII	ASCII encoding instance.
TEncoding.Default	Default codepage.
TEncoding.BigEndianUnicode	Big-endian Unicode (UTF16BE) encoding instance.
TEncoding.Unicode	UTF16 encoding instance.
TEncoding.UTF7	UTF7 encoding instance.
TEncoding.UTF8	UTF8 encoding instance.