TCharacter.ConvertToUtf32 function

Member of TCharacterpublicIn unit Character

Convert a UTF16 character to a UTF32 character.

Declaration

pascal

class function ConvertToUtf32(const AString: UnicodeString; 
 AIndex: Integer): UCS4Char; overload
 ; static
class function ConvertToUtf32(const AString: UnicodeString; 
 AIndex: Integer; out ACharLength: Integer)
: UCS4Char; overload; static
class function ConvertToUtf32(const AHighSurrogate: UnicodeChar; 
 const ALowSurrogate: UnicodeChar)
: UCS4Char; overload; static

Arguments

`AString`	String containing the character to encode.
`AIndex`	Index at which the character to encode is located.
`ACharLength`	Character length (in UTF16 characters).
`AHighSurrogate`	The high pair of the surrogate.
`ALowSurrogate`	The low pair of the surrogate.

Function result

The Unicode character in UTF32 format.

Description

TCharacter.ConvertToUtf32 converts a UTF16-encoded Unicode character to a Unicode32 character. This is the opposite of ConvertFromUtf32. The function exists in several overloaded versions, to be able to present the Unicode character in one of 2 ways:

As a position AIndex (in unicodechar units) in a string AString to a Unicode32 character. The source is a string, since multiple UTF16 characters can be needed to encode a single UTF32 character. In this form, Optionally, the character length (1 or 2) can be returned in ACharLength.
As 2 UTF16 Unicode characters, representing the high and low surrogate pairs: AHighSurrogate and ALowSurrogate.

Errors

If AIndex is not a valid character index in the string AString, an EArgumentOutOfRangeException exception is raised. If the character at that position is not complete, an EArgumentException exception is raised.