QChar 类

QChar 类提供 16 位 Unicode 字符。 更多...

Header: #include <QChar>
CMake: find_package(Qt6 COMPONENTS Core REQUIRED)
target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake: QT += core

注意: 此类的所有函数 可重入 .

公共类型

enum Category { Mark_NonSpacing, Mark_SpacingCombining, Mark_Enclosing, Number_DecimalDigit, Number_Letter, …, Symbol_Other }
enum Decomposition { NoDecomposition, Canonical, Circle, Compat, Final, …, Wide }
enum Direction { DirAL, DirAN, DirB, DirBN, DirCS, …, DirWS }
enum JoiningType { Joining_None, Joining_Causing, Joining_Dual, Joining_Right, Joining_Left, Joining_Transparent }
enum Script { Script_Unknown, Script_Inherited, Script_Common, Script_Adlam, Script_Ahom, …, Script_ZanabazarSquare }
enum SpecialCharacter { Null, Tabulation, LineFeed, FormFeed, CarriageReturn, …, LastValidCodePoint }
enum UnicodeVersion { Unicode_1_1, Unicode_2_0, Unicode_2_1_2, Unicode_3_0, Unicode_3_1, …, Unicode_Unassigned }

公共函数

QChar (uchar ch )
QChar (char ch )
QChar (wchar_t ch )
QChar (char16_t ch )
QChar (QLatin1Char ch )
QChar (QChar::SpecialCharacter ch )
QChar (int code )
QChar (uint code )
QChar (short code )
QChar (uchar cell , uchar row )
QChar (ushort code )
QChar ()
QChar::Category category () const
uchar cell () const
unsigned char combiningClass () const
QString decomposition () const
QChar::Decomposition decompositionTag () const
int digitValue () const
QChar::Direction direction () const
bool hasMirrored () const
bool isDigit () const
bool isHighSurrogate () const
bool isLetter () const
bool isLetterOrNumber () const
bool isLowSurrogate () const
bool isLower () const
bool isMark () const
bool isNonCharacter () const
bool isNull () const
bool isNumber () const
bool isPrint () const
bool isPunct () const
bool isSpace () const
bool isSurrogate () const
bool isSymbol () const
bool isTitleCase () const
bool isUpper () const
QChar::JoiningType joiningType () const
QChar mirroredChar () const
uchar row () const
QChar::Script script () const
QChar toCaseFolded () const
char toLatin1 () const
QChar toLower () const
QChar toTitleCase () const
QChar toUpper () const
char16_t unicode () const
char16_t & unicode ()
QChar::UnicodeVersion unicodeVersion () const

静态公共成员

QChar::Category category (char32_t ucs4 )
unsigned char combiningClass (char32_t ucs4 )
QChar::UnicodeVersion currentUnicodeVersion ()
QString decomposition (char32_t ucs4 )
QChar::Decomposition decompositionTag (char32_t ucs4 )
int digitValue (char32_t ucs4 )
QChar::Direction direction (char32_t ucs4 )
QChar fromLatin1 (char c )
QChar fromUcs2 (char16_t c )
R fromUcs4 (char32_t c )
bool hasMirrored (char32_t ucs4 )
char16_t highSurrogate (char32_t ucs4 )
bool isDigit (char32_t ucs4 )
bool isHighSurrogate (char32_t ucs4 )
bool isLetter (char32_t ucs4 )
bool isLetterOrNumber (char32_t ucs4 )
bool isLowSurrogate (char32_t ucs4 )
bool isLower (char32_t ucs4 )
bool isMark (char32_t ucs4 )
bool isNonCharacter (char32_t ucs4 )
bool isNumber (char32_t ucs4 )
bool isPrint (char32_t ucs4 )
bool isPunct (char32_t ucs4 )
bool isSpace (char32_t ucs4 )
bool isSurrogate (char32_t ucs4 )
bool isSymbol (char32_t ucs4 )
bool isTitleCase (char32_t ucs4 )
bool isUpper (char32_t ucs4 )
QChar::JoiningType joiningType (char32_t ucs4 )
char16_t lowSurrogate (char32_t ucs4 )
char32_t mirroredChar (char32_t ucs4 )
bool requiresSurrogates (char32_t ucs4 )
QChar::Script script (char32_t ucs4 )
char32_t surrogateToUcs4 (char16_t high , char16_t low )
char32_t surrogateToUcs4 (QChar high , QChar low )
char32_t toCaseFolded (char32_t ucs4 )
char32_t toLower (char32_t ucs4 )
char32_t toTitleCase (char32_t ucs4 )
char32_t toUpper (char32_t ucs4 )
QChar::UnicodeVersion unicodeVersion (char32_t ucs4 )
bool operator!= (QChar c1 , QChar c2 )
bool operator< (QChar c1 , QChar c2 )
QDataStream & operator<< (QDataStream & out , QChar chr )
bool operator<= (QChar c1 , QChar c2 )
bool operator== (QChar c1 , QChar c2 )
bool operator> (QChar c1 , QChar c2 )
bool operator>= (QChar c1 , QChar c2 )
QDataStream & operator>> (QDataStream & in , QChar & chr )

详细描述

In Qt, Unicode characters are 16-bit entities without any markup or structure. This class represents such an entity. It is lightweight, so it can be used everywhere. Most compilers treat it like an unsigned short .

QChar provides a full complement of testing/classification functions, converting to and from other formats, converting from composed to decomposed Unicode, and trying to compare and case-convert if you ask it to.

The classification functions include functions like those in the standard C++ header <cctype> (formerly <ctype.h>), but operating on the full range of Unicode characters, not just for the ASCII range. They all return true if the character is a certain type of character; otherwise they return false. These classification functions are isNull () (returns true if the character is '\0'), isPrint () (true if the character is any sort of printable character, including whitespace), isPunct () (any sort of punctation), isMark () (Unicode Mark), isLetter () (a letter), isNumber () (any sort of numeric character, not just 0-9), isLetterOrNumber (),和 isDigit () (decimal digits). All of these are wrappers around category () which return the Unicode-defined category of each character. Some of these also calculate the derived properties (for example isSpace () 返回 true if the character is of category Separator_* or an exceptional code point from Other_Control category).

QChar also provides direction (), which indicates the "natural" writing direction of this character. The joiningType () function indicates how the character joins with it's neighbors (needed mostly for Arabic or Syriac) and finally hasMirrored (), which indicates whether the character needs to be mirrored when it is printed in it's "unnatural" writing direction.

Composed Unicode characters (like ring ) can be converted to decomposed Unicode ("a" followed by "ring above") by using decomposition ().

In Unicode, comparison is not necessarily possible and case conversion is very difficult at best. Unicode, covering the "entire" world, also includes most of the world's case and sorting problems. operator==() and friends will do comparison based purely on the numeric Unicode value (code point) of the characters, and toUpper () 和 toLower () will do case changes when the character has a well-defined uppercase/lowercase equivalent. For locale-dependent comparisons, use QString::localeAwareCompare ().

The conversion functions include unicode () (to a scalar), toLatin1 () (to scalar, but converts all non-Latin-1 characters to 0), row () (gives the Unicode row), cell () (gives the Unicode cell), digitValue () (gives the integer value of any of the numerous digit characters), and a host of constructors.

QChar provides constructors and cast operators that make it easy to convert to and from traditional 8-bit char s. If you defined QT_NO_CAST_FROM_ASCII and QT_NO_CAST_TO_ASCII , as explained in the QString documentation, you will need to explicitly call fromLatin1 (), or use QLatin1Char , to construct a QChar from an 8-bit char , and you will need to call toLatin1 () to get the 8-bit value back.

Starting with Qt 6.0, most QChar constructors are explicit . This is done to avoid dangerous mistakes when accidentally mixing integral types and strings. You can opt-out (and make these constructors implicit) by defining the macro QT_IMPLICIT_QCHAR_CONSTRUCTION .

更多信息见 "About the Unicode Character Database" .

另请参阅 Unicode , QString ,和 QLatin1Char .

成员类型文档编制

enum QChar:: Category

This enum maps the Unicode character categories.

The following characters are normative in Unicode:

常量 描述
QChar::Mark_NonSpacing 0 Unicode class name Mn
QChar::Mark_SpacingCombining 1 Unicode class name Mc
QChar::Mark_Enclosing 2 Unicode class name Me
QChar::Number_DecimalDigit 3 Unicode class name Nd
QChar::Number_Letter 4 Unicode class name Nl
QChar::Number_Other 5 Unicode class name No
QChar::Separator_Space 6 Unicode class name Zs
QChar::Separator_Line 7 Unicode class name Zl
QChar::Separator_Paragraph 8 Unicode class name Zp
QChar::Other_Control 9 Unicode class name Cc
QChar::Other_Format 10 Unicode class name Cf
QChar::Other_Surrogate 11 Unicode class name Cs
QChar::Other_PrivateUse 12 Unicode class name Co
QChar::Other_NotAssigned 13 Unicode class name Cn

The following categories are informative in Unicode:

常量 描述
QChar::Letter_Uppercase 14 Unicode class name Lu
QChar::Letter_Lowercase 15 Unicode class name Ll
QChar::Letter_Titlecase 16 Unicode class name Lt
QChar::Letter_Modifier 17 Unicode class name Lm
QChar::Letter_Other 18 Unicode class name Lo
QChar::Punctuation_Connector 19 Unicode class name Pc
QChar::Punctuation_Dash 20 Unicode class name Pd
QChar::Punctuation_Open 21 Unicode class name Ps
QChar::Punctuation_Close 22 Unicode class name Pe
QChar::Punctuation_InitialQuote 23 Unicode class name Pi
QChar::Punctuation_FinalQuote 24 Unicode class name Pf
QChar::Punctuation_Other 25 Unicode class name Po
QChar::Symbol_Math 26 Unicode class name Sm
QChar::Symbol_Currency 27 Unicode class name Sc
QChar::Symbol_Modifier 28 Unicode class name Sk
QChar::Symbol_Other 29 Unicode class name So

另请参阅 category ().

enum QChar:: Decomposition

This enum type defines the Unicode decomposition attributes. See the Unicode Standard for a description of the values.

常量
QChar::NoDecomposition 0
QChar::Canonical 1
QChar::Circle 8
QChar::Compat 16
QChar::Final 6
QChar::Font 2
QChar::Fraction 17
QChar::Initial 4
QChar::Isolated 7
QChar::Medial 5
QChar::Narrow 13
QChar::NoBreak 3
QChar::Small 14
QChar::Square 15
QChar::Sub 10
QChar::Super 9
QChar::Vertical 11
QChar::Wide 12

另请参阅 decomposition ().

enum QChar:: Direction

This enum type defines the Unicode direction attributes. See the Unicode Standard for a description of the values.

In order to conform to C/C++ naming conventions "Dir" is prepended to the codes used in the Unicode Standard.

常量 描述
QChar::DirAL 13
QChar::DirAN 5
QChar::DirB 7
QChar::DirBN 18
QChar::DirCS 6
QChar::DirEN 2
QChar::DirES 3
QChar::DirET 4
QChar::DirFSI 21 Since Qt 5.3
QChar::DirL 0
QChar::DirLRE 11
QChar::DirLRI 19 Since Qt 5.3
QChar::DirLRO 12
QChar::DirNSM 17
QChar::DirON 10
QChar::DirPDF 16
QChar::DirPDI 22 Since Qt 5.3
QChar::DirR 1
QChar::DirRLE 14
QChar::DirRLI 20 Since Qt 5.3
QChar::DirRLO 15
QChar::DirS 8
QChar::DirWS 9

另请参阅 direction ().

enum QChar:: JoiningType

since 5.3

This enum type defines the Unicode joining type attributes. See the Unicode Standard for a description of the values.

In order to conform to C/C++ naming conventions "Joining_" is prepended to the codes used in the Unicode Standard.

常量
QChar::Joining_None 0
QChar::Joining_Causing 1
QChar::Joining_Dual 2
QChar::Joining_Right 3
QChar::Joining_Left 4
QChar::Joining_Transparent 5

另请参阅 joiningType ().

[since 5.1] enum QChar:: Script

This enum type defines the Unicode script property values.

For details about the Unicode script property values see Unicode Standard Annex #24 .

In order to conform to C/C++ naming conventions "Script_" is prepended to the codes used in the Unicode Standard.

常量 描述
QChar::Script_Unknown 0 For unassigned, private-use, noncharacter, and surrogate code points.
QChar::Script_Inherited 1 For characters that may be used with multiple scripts and that inherit their script from the preceding characters. These include nonspacing marks, enclosing marks, and zero width joiner/non-joiner characters.
QChar::Script_Common 2 For characters that may be used with multiple scripts and that do not inherit their script from the preceding characters.
QChar::Script_Adlam 132 Since Qt 5.11
QChar::Script_Ahom 126 Since Qt 5.6
QChar::Script_AnatolianHieroglyphs 127 Since Qt 5.6
QChar::Script_Arabic 8
QChar::Script_Armenian 6
QChar::Script_Avestan 80
QChar::Script_Balinese 62
QChar::Script_Bamum 84
QChar::Script_BassaVah 104 Since Qt 5.5
QChar::Script_Batak 93
QChar::Script_Bengali 12
QChar::Script_Bhaiksuki 133 Since Qt 5.11
QChar::Script_Bopomofo 36
QChar::Script_Brahmi 94
QChar::Script_Braille 54
QChar::Script_Buginese 55
QChar::Script_Buhid 44
QChar::Script_CanadianAboriginal 29
QChar::Script_Carian 75
QChar::Script_CaucasianAlbanian 103 Since Qt 5.5
QChar::Script_Chakma 96
QChar::Script_Cham 77
QChar::Script_Cherokee 28
QChar::Script_Chorasmian 153 Since Qt 5.15
QChar::Script_Coptic 46
QChar::Script_Cuneiform 63
QChar::Script_Cypriot 53
QChar::Script_Cyrillic 5
QChar::Script_Deseret 41
QChar::Script_Devanagari 11
QChar::Script_DivesAkuru 154 Since Qt 5.15
QChar::Script_Dogra 142 Since Qt 5.15
QChar::Script_Duployan 105 Since Qt 5.5
QChar::Script_EgyptianHieroglyphs 81
QChar::Script_Elbasan 106 Since Qt 5.5
QChar::Script_Elymaic 149 Since Qt 5.15
QChar::Script_Ethiopic 27
QChar::Script_Georgian 25
QChar::Script_Glagolitic 57
QChar::Script_Gothic 40
QChar::Script_Grantha 107 Since Qt 5.5
QChar::Script_Greek 4
QChar::Script_Gujarati 14
QChar::Script_GunjalaGondi 143 Since Qt 5.15
QChar::Script_Gurmukhi 13
QChar::Script_Han 37
QChar::Script_Hangul 26
QChar::Script_HanifiRohingya 144 Since Qt 5.15
QChar::Script_Hanunoo 43
QChar::Script_Hatran 128 Since Qt 5.6
QChar::Script_Hebrew 7
QChar::Script_Hiragana 34
QChar::Script_ImperialAramaic 87
QChar::Script_InscriptionalPahlavi 90
QChar::Script_InscriptionalParthian 89
QChar::Script_Javanese 85
QChar::Script_Kaithi 92
QChar::Script_Kannada 18
QChar::Script_Katakana 35
QChar::Script_KayahLi 72
QChar::Script_Kharoshthi 61
QChar::Script_KhitanSmallScript 155 Since Qt 5.15
QChar::Script_Khmer 32
QChar::Script_Khojki 109 Since Qt 5.5
QChar::Script_Khudawadi 123 Since Qt 5.5
QChar::Script_Lao 22
QChar::Script_Latin 3
QChar::Script_Lepcha 68
QChar::Script_Limbu 47
QChar::Script_LinearA 110 Since Qt 5.5
QChar::Script_LinearB 49
QChar::Script_Lisu 83
QChar::Script_Lycian 74
QChar::Script_Lydian 76
QChar::Script_Mahajani 111 Since Qt 5.5
QChar::Script_Makasar 145 Since Qt 5.15
QChar::Script_Malayalam 19
QChar::Script_Mandaic 95
QChar::Script_Manichaean 112 Since Qt 5.5
QChar::Script_Marchen 134 Since Qt 5.11
QChar::Script_MasaramGondi 138 Since Qt 5.11
QChar::Script_Medefaidrin 146 Since Qt 5.15
QChar::Script_MeeteiMayek 86
QChar::Script_MendeKikakui 113 Since Qt 5.5
QChar::Script_MeroiticCursive 97
QChar::Script_MeroiticHieroglyphs 98
QChar::Script_Miao 99
QChar::Script_Modi 114 Since Qt 5.5
QChar::Script_Mongolian 33
QChar::Script_Mro 115 Since Qt 5.5
QChar::Script_Multani 129 Since Qt 5.6
QChar::Script_Myanmar 24
QChar::Script_Nabataean 117 Since Qt 5.5
QChar::Script_Nandinagari 150 Since Qt 5.15
QChar::Script_Newa 135 Since Qt 5.11
QChar::Script_NewTaiLue 56
QChar::Script_Nko 66
QChar::Script_Nushu 139 Since Qt 5.11
QChar::Script_NyiakengPuachueHmong 151 Since Qt 5.15
QChar::Script_Ogham 30
QChar::Script_OlChiki 69
QChar::Script_OldHungarian 130 Since Qt 5.6
QChar::Script_OldItalic 39
QChar::Script_OldNorthArabian 116 Since Qt 5.5
QChar::Script_OldPermic 120 Since Qt 5.5
QChar::Script_OldPersian 60
QChar::Script_OldSogdian 147 Since Qt 5.15
QChar::Script_OldSouthArabian 88
QChar::Script_OldTurkic 91
QChar::Script_Oriya 15
QChar::Script_Osage 136 Since Qt 5.11
QChar::Script_Osmanya 52
QChar::Script_PahawhHmong 108 Since Qt 5.5
QChar::Script_Palmyrene 118 Since Qt 5.5
QChar::Script_PauCinHau 119 Since Qt 5.5
QChar::Script_PhagsPa 65
QChar::Script_Phoenician 64
QChar::Script_PsalterPahlavi 121 Since Qt 5.5
QChar::Script_Rejang 73
QChar::Script_Runic 31
QChar::Script_Samaritan 82
QChar::Script_Saurashtra 71
QChar::Script_Sharada 100
QChar::Script_Shavian 51
QChar::Script_Siddham 122 Since Qt 5.5
QChar::Script_SignWriting 131 Since Qt 5.6
QChar::Script_Sinhala 20
QChar::Script_Sogdian 148 Since Qt 5.15
QChar::Script_SoraSompeng 101
QChar::Script_Soyombo 140 Since Qt 5.11
QChar::Script_Sundanese 67
QChar::Script_SylotiNagri 59
QChar::Script_Syriac 9
QChar::Script_Tagalog 42
QChar::Script_Tagbanwa 45
QChar::Script_TaiLe 48
QChar::Script_TaiTham 78
QChar::Script_TaiViet 79
QChar::Script_Takri 102
QChar::Script_Tamil 16
QChar::Script_Tangut 137 Since Qt 5.11
QChar::Script_Telugu 17
QChar::Script_Thaana 10
QChar::Script_Thai 21
QChar::Script_Tibetan 23
QChar::Script_Tifinagh 58
QChar::Script_Tirhuta 124 Since Qt 5.5
QChar::Script_Ugaritic 50
QChar::Script_Vai 70
QChar::Script_Wancho 152 Since Qt 5.15
QChar::Script_WarangCiti 125 Since Qt 5.5
QChar::Script_Yezidi 156 Since Qt 5.15
QChar::Script_Yi 38
QChar::Script_ZanabazarSquare 141 Since Qt 5.11

该枚举在 Qt 5.1 引入或被修改。

另请参阅 script ().

enum QChar:: SpecialCharacter

常量 描述
QChar::Null 0x0000 A QChar with this value isNull ().
QChar::Tabulation 0x0009 Character tabulation.
QChar::LineFeed 0x000a
QChar::FormFeed 0x000c
QChar::CarriageReturn 0x000d
QChar::Space 0x0020
QChar::Nbsp 0x00a0 Non-breaking space.
QChar::SoftHyphen 0x00ad
QChar::ReplacementCharacter 0xfffd The character shown when a font has no glyph for a certain codepoint. A special question mark character is often used. Codecs use this codepoint when input data cannot be represented in Unicode.
QChar::ObjectReplacementCharacter 0xfffc Used to represent an object such as an image when such objects cannot be presented.
QChar::ByteOrderMark 0xfeff
QChar::ByteOrderSwapped 0xfffe
QChar::ParagraphSeparator 0x2029
QChar::LineSeparator 0x2028
QChar::LastValidCodePoint 0x10ffff

enum QChar:: UnicodeVersion

Specifies which version of the Unicode standard introduced a certain character.

常量 描述
QChar::Unicode_1_1 1 版本 1.1
QChar::Unicode_2_0 2 Version 2.0
QChar::Unicode_2_1_2 3 Version 2.1.2
QChar::Unicode_3_0 4 版本 3.0
QChar::Unicode_3_1 5 版本 3.1
QChar::Unicode_3_2 6 Version 3.2
QChar::Unicode_4_0 7 Version 4.0
QChar::Unicode_4_1 8 Version 4.1
QChar::Unicode_5_0 9 Version 5.0
QChar::Unicode_5_1 10 Version 5.1
QChar::Unicode_5_2 11 Version 5.2
QChar::Unicode_6_0 12 Version 6.0
QChar::Unicode_6_1 13 Version 6.1
QChar::Unicode_6_2 14 Version 6.2
QChar::Unicode_6_3 15 Version 6.3 Since Qt 5.3
QChar::Unicode_7_0 16 Version 7.0 Since Qt 5.5
QChar::Unicode_8_0 17 Version 8.0 Since Qt 5.6
QChar::Unicode_9_0 18 Version 9.0 Since Qt 5.11
QChar::Unicode_10_0 19 Version 10.0 Since Qt 5.11
QChar::Unicode_11_0 20 Version 11.0 Since Qt 5.15
QChar::Unicode_12_0 21 Version 12.0 Since Qt 5.15
QChar::Unicode_12_1 22 Version 12.1 Since Qt 5.15
QChar::Unicode_13_0 23 Version 13.0 Since Qt 5.15
QChar::Unicode_Unassigned 0 The value is not assigned to any character in version 8.0 of Unicode.

另请参阅 unicodeVersion () 和 currentUnicodeVersion ().

成员函数文档编制

QChar:: QChar ( uchar ch )

Constructs a QChar corresponding to ASCII/Latin-1 character ch .

注意: This constructor is not available when QT_NO_CAST_FROM_ASCII or QT_RESTRICTED_CAST_FROM_ASCII is defined.

另请参阅 QT_NO_CAST_FROM_ASCII and QT_RESTRICTED_CAST_FROM_ASCII .

QChar:: QChar ( char ch )

Constructs a QChar corresponding to ASCII/Latin-1 character ch .

注意: This constructor is not available when QT_NO_CAST_FROM_ASCII is defined.

另请参阅 QT_NO_CAST_FROM_ASCII .

[since 5.10] QChar:: QChar ( wchar_t ch )

Constructs a QChar corresponding to the wide character ch .

注意: This constructor is only available on Windows.

该函数在 Qt 5.10 引入。

[since 5.10] QChar:: QChar ( char16_t ch )

Constructs a QChar corresponding to the UTF-16 character ch .

该函数在 Qt 5.10 引入。

QChar:: QChar ( QLatin1Char ch )

Constructs a QChar corresponding to ASCII/Latin-1 character ch .

QChar:: QChar ( QChar::SpecialCharacter ch )

Constructs a QChar for the predefined character value ch .

QChar:: QChar ( int code )

Constructs a QChar for the character with Unicode code point code .

QChar:: QChar ( uint code )

Constructs a QChar for the character with Unicode code point code .

QChar:: QChar ( short code )

Constructs a QChar for the character with Unicode code point code .

QChar:: QChar ( uchar cell , uchar row )

Constructs a QChar for Unicode cell cell in row row .

另请参阅 cell () 和 row ().

QChar:: QChar ( ushort code )

Constructs a QChar for the character with Unicode code point code .

QChar:: QChar ()

Constructs a null QChar ('\0').

另请参阅 isNull ().

QChar::Category QChar:: category () const

Returns the character's category.

[static] QChar::Category QChar:: category ( char32_t ucs4 )

这是重载函数。

Returns the category of the UCS-4-encoded character specified by ucs4 .

注意: Before Qt 6, this function took a uint 自变量。

uchar QChar:: cell () const

Returns the cell (least significant byte) of the Unicode character.

另请参阅 row ().

unsigned char QChar:: combiningClass () const

Returns the combining class for the character as defined in the Unicode standard. This is mainly useful as a positioning hint for marks attached to a base character.

The Qt text rendering engine uses this information to correctly position non-spacing marks around a base character.

[static] unsigned char QChar:: combiningClass ( char32_t ucs4 )

这是重载函数。

Returns the combining class for the UCS-4-encoded character specified by ucs4 , as defined in the Unicode standard.

注意: Before Qt 6, this function took a uint 自变量。

[static] QChar::UnicodeVersion QChar:: currentUnicodeVersion ()

Returns the most recent supported Unicode version.

QString QChar:: decomposition () const

Decomposes a character into it's constituent parts. Returns an empty string if no decomposition exists.

[static] QString QChar:: decomposition ( char32_t ucs4 )

这是重载函数。

Decomposes the UCS-4-encoded character specified by ucs4 into it's constituent parts. Returns an empty string if no decomposition exists.

注意: Before Qt 6, this function took a uint 自变量。

QChar::Decomposition QChar:: decompositionTag () const

Returns the tag defining the composition of the character. Returns QChar::NoDecomposition if no decomposition exists.

[static] QChar::Decomposition QChar:: decompositionTag ( char32_t ucs4 )

这是重载函数。

Returns the tag defining the composition of the UCS-4-encoded character specified by ucs4 。返回 QChar::NoDecomposition if no decomposition exists.

注意: Before Qt 6, this function took a uint 自变量。

int QChar:: digitValue () const

Returns the numeric value of the digit, or -1 if the character is not a digit.

[static] int QChar:: digitValue ( char32_t ucs4 )

这是重载函数。

Returns the numeric value of the digit specified by the UCS-4-encoded character, ucs4 , or -1 if the character is not a digit.

注意: Before Qt 6, this function took a uint 自变量。

QChar::Direction QChar:: direction () const

Returns the character's direction.

[static] QChar::Direction QChar:: direction ( char32_t ucs4 )

这是重载函数。

Returns the direction of the UCS-4-encoded character specified by ucs4 .

注意: Before Qt 6, this function took a uint 自变量。

[static] QChar QChar:: fromLatin1 ( char c )

Converts the Latin-1 character c to its equivalent QChar . This is mainly useful for non-internationalized software.

An alternative is to use QLatin1Char .

另请参阅 toLatin1 () 和 unicode ().

[static, since 6.0] QChar QChar:: fromUcs2 ( char16_t c )

构造 QChar from UTF-16 character c .

该函数在 Qt 6.0 引入。

另请参阅 fromUcs4 ().

[static, since 6.0] R QChar:: fromUcs4 ( char32_t c )

Returns an anonymous struct that

  • contains a char16_t chars[2] array,
  • can be implicitly converted to a QStringView ,和
  • iterated over with a C++11 ranged for loop.

c requires surrogates, chars[0] contains the high surrogate and chars[1] the low surrogate, and the QStringView has size 2. Otherwise, chars[0] contains c and chars[1] is null ,和 QStringView has size 1.

This allows easy use of the result:

QString s;
s += QChar::fromUcs4(ch);
							
for (char16_t c16 : QChar::fromUcs4(ch))
    use(c16);
							

该函数在 Qt 6.0 引入。

另请参阅 fromUcs2 () 和 requiresSurrogates ().

bool QChar:: hasMirrored () const

返回 true if the character should be reversed if the text direction is reversed; otherwise returns false .

A bit faster equivalent of (ch. mirroredChar () != ch).

另请参阅 mirroredChar ().

[static, since 5.0] bool QChar:: hasMirrored ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 should be reversed if the text direction is reversed; otherwise returns false .

A bit faster equivalent of ( QChar::mirroredChar (ucs4) != ucs4).

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

另请参阅 mirroredChar ().

[static] char16_t QChar:: highSurrogate ( char32_t ucs4 )

Returns the high surrogate part of a UCS-4-encoded code point. The returned result is undefined if ucs4 is smaller than 0x10000.

注意: Before Qt 6, this function took a uint argument and returned ushort .

bool QChar:: isDigit () const

返回 true if the character is a decimal digit ( Number_DecimalDigit ); otherwise returns false .

另请参阅 isNumber ().

[static, since 5.0] bool QChar:: isDigit ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a decimal digit ( Number_DecimalDigit ); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

另请参阅 isNumber ().

bool QChar:: isHighSurrogate () const

返回 true QChar is the high part of a UTF16 surrogate (for example if its code point is in range [0xd800..0xdbff]); false otherwise.

[static] bool QChar:: isHighSurrogate ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is the high part of a UTF16 surrogate (for example if its code point is in range [0xd800..0xdbff]); false otherwise.

注意: Before Qt 6, this function took a uint 自变量。

bool QChar:: isLetter () const

返回 true if the character is a letter (Letter_* categories); otherwise returns false .

[static, since 5.0] bool QChar:: isLetter ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a letter (Letter_* categories); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isLetterOrNumber () const

返回 true if the character is a letter or number (Letter_* or Number_* categories); otherwise returns false .

[static, since 5.0] bool QChar:: isLetterOrNumber ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a letter or number (Letter_* or Number_* categories); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isLowSurrogate () const

返回 true QChar is the low part of a UTF16 surrogate (for example if its code point is in range [0xdc00..0xdfff]); false otherwise.

[static] bool QChar:: isLowSurrogate ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is the low part of a UTF16 surrogate (for example if its code point is in range [0xdc00..0xdfff]); false otherwise.

注意: Before Qt 6, this function took a uint 自变量。

bool QChar:: isLower () const

返回 true if the character is a lowercase letter, for example category () 是 Letter_Lowercase .

另请参阅 isUpper (), toLower (),和 toUpper ().

[static, since 5.0] bool QChar:: isLower ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a lowercase letter, for example category () 是 Letter_Lowercase .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

另请参阅 isUpper (), toLower (),和 toUpper ().

bool QChar:: isMark () const

返回 true if the character is a mark (Mark_* categories); otherwise returns false .

QChar::Category for more information regarding marks.

[static, since 5.0] bool QChar:: isMark ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a mark (Mark_* categories); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

[since 5.0] bool QChar:: isNonCharacter () const

返回 true QChar is a non-character; false otherwise.

Unicode has a certain number of code points that are classified as "non-characters:" that is, they can be used for internal purposes in applications but cannot be used for text interchange. Those are the last two entries each Unicode Plane ([0xfffe..0xffff], [0x1fffe..0x1ffff], etc.) as well as the entries in range [0xfdd0..0xfdef].

该函数在 Qt 5.0 引入。

[static, since 5.0] bool QChar:: isNonCharacter ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a non-character; false otherwise.

Unicode has a certain number of code points that are classified as "non-characters:" that is, they can be used for internal purposes in applications but cannot be used for text interchange. Those are the last two entries each Unicode Plane ([0xfffe..0xffff], [0x1fffe..0x1ffff], etc.) as well as the entries in range [0xfdd0..0xfdef].

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isNull () const

返回 true if the character is the Unicode character 0x0000 ('\0'); otherwise returns false .

bool QChar:: isNumber () const

返回 true if the character is a number (Number_* categories, not just 0-9); otherwise returns false .

另请参阅 isDigit ().

[static, since 5.0] bool QChar:: isNumber ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a number (Number_* categories, not just 0-9); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

另请参阅 isDigit ().

bool QChar:: isPrint () const

返回 true if the character is a printable character; otherwise returns false . This is any character not of category Other_*.

Note that this gives no indication of whether the character is available in a particular font.

[static, since 5.0] bool QChar:: isPrint ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a printable character; otherwise returns false . This is any character not of category Other_*.

Note that this gives no indication of whether the character is available in a particular font.

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isPunct () const

返回 true if the character is a punctuation mark (Punctuation_* categories); otherwise returns false .

[static, since 5.0] bool QChar:: isPunct ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a punctuation mark (Punctuation_* categories); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isSpace () const

返回 true if the character is a separator character (Separator_* categories or certain code points from Other_Control category); otherwise returns false .

[static, since 5.0] bool QChar:: isSpace ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a separator character (Separator_* categories or certain code points from Other_Control category); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

[since 5.0] bool QChar:: isSurrogate () const

返回 true QChar contains a code point that is in either the high or the low part of the UTF-16 surrogate range (for example if its code point is in range [0xd800..0xdfff]); false otherwise.

该函数在 Qt 5.0 引入。

[static, since 5.0] bool QChar:: isSurrogate ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 contains a code point that is in either the high or the low part of the UTF-16 surrogate range (for example if its code point is in range [0xd800..0xdfff]); false otherwise.

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isSymbol () const

返回 true if the character is a symbol (Symbol_* categories); otherwise returns false .

[static, since 5.0] bool QChar:: isSymbol ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a symbol (Symbol_* categories); otherwise returns false .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

bool QChar:: isTitleCase () const

返回 true if the character is a titlecase letter, for example category () 是 Letter_Titlecase .

另请参阅 isLower (), toUpper (), toLower (),和 toTitleCase ().

[static, since 5.0] bool QChar:: isTitleCase ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is a titlecase letter, for example category () 是 Letter_Titlecase .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

另请参阅 isLower (), toUpper (), toLower (),和 toTitleCase ().

bool QChar:: isUpper () const

返回 true if the character is an uppercase letter, for example category () 是 Letter_Uppercase .

另请参阅 isLower (), toUpper (),和 toLower ().

[static, since 5.0] bool QChar:: isUpper ( char32_t ucs4 )

这是重载函数。

返回 true if the UCS-4-encoded character specified by ucs4 is an uppercase letter, for example category () 是 Letter_Uppercase .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.0 引入。

另请参阅 isLower (), toUpper (),和 toLower ().

[since 5.3] QChar::JoiningType QChar:: joiningType () const

Returns information about the joining type attributes of the character (needed for certain languages such as Arabic or Syriac).

该函数在 Qt 5.3 引入。

[static, since 5.3] QChar::JoiningType QChar:: joiningType ( char32_t ucs4 )

这是重载函数。

Returns information about the joining type attributes of the UCS-4-encoded character specified by ucs4 (needed for certain languages such as Arabic or Syriac).

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.3 引入。

[static] char16_t QChar:: lowSurrogate ( char32_t ucs4 )

Returns the low surrogate part of a UCS-4-encoded code point. The returned result is undefined if ucs4 is smaller than 0x10000.

注意: Before Qt 6, this function took a uint argument and returned ushort .

QChar QChar:: mirroredChar () const

Returns the mirrored character if this character is a mirrored character; otherwise returns the character itself.

另请参阅 hasMirrored ().

[static] char32_t QChar:: mirroredChar ( char32_t ucs4 )

这是重载函数。

Returns the mirrored character if the UCS-4-encoded character specified by ucs4 is a mirrored character; otherwise returns the character itself.

注意: Before Qt 6, this function took a uint argument and returned uint .

另请参阅 hasMirrored ().

[static] bool QChar:: requiresSurrogates ( char32_t ucs4 )

返回 true if the UCS-4-encoded character specified by ucs4 can be split into the high and low parts of a UTF16 surrogate (for example if its code point is greater than or equals to 0x10000); false otherwise.

注意: Before Qt 6, this function took a uint 自变量。

uchar QChar:: row () const

Returns the row (most significant byte) of the Unicode character.

另请参阅 cell ().

[since 5.1] QChar::Script QChar:: script () const

Returns the Unicode script property value for this character.

该函数在 Qt 5.1 引入。

[static, since 5.1] QChar::Script QChar:: script ( char32_t ucs4 )

这是重载函数。

Returns the Unicode script property value for the character specified in its UCS-4-encoded form as ucs4 .

注意: Before Qt 6, this function took a uint 自变量。

该函数在 Qt 5.1 引入。

[static] char32_t QChar:: surrogateToUcs4 ( char16_t high , char16_t low )

Converts a UTF16 surrogate pair with the given high and low values to it's UCS-4-encoded code point.

注意: Before Qt 6, this function took ushort arguments and returned uint .

[static] char32_t QChar:: surrogateToUcs4 ( QChar high , QChar low )

这是重载函数。

Converts a UTF16 surrogate pair ( high , low ) to it's UCS-4-encoded code point.

注意: Before Qt 6, this function returned uint .

QChar QChar:: toCaseFolded () const

Returns the case folded equivalent of the character. For most Unicode characters this is the same as toLower ().

[static] char32_t QChar:: toCaseFolded ( char32_t ucs4 )

这是重载函数。

Returns the case folded equivalent of the UCS-4-encoded character specified by ucs4 . For most Unicode characters this is the same as toLower ().

注意: Before Qt 6, this function took a uint argument and returned uint .

char QChar:: toLatin1 () const

Returns the Latin-1 character equivalent to the QChar , or 0. This is mainly useful for non-internationalized software.

注意: It is not possible to distinguish a non-Latin-1 character from a Latin-1 0 (NUL) character. Prefer to use unicode (), which does not have this ambiguity.

另请参阅 unicode ().

QChar QChar:: toLower () const

Returns the lowercase equivalent if the character is uppercase or titlecase; otherwise returns the character itself.

[static] char32_t QChar:: toLower ( char32_t ucs4 )

这是重载函数。

Returns the lowercase equivalent of the UCS-4-encoded character specified by ucs4 if the character is uppercase or titlecase; otherwise returns the character itself.

注意: Before Qt 6, this function took a uint argument and returned uint .

QChar QChar:: toTitleCase () const

Returns the title case equivalent if the character is lowercase or uppercase; otherwise returns the character itself.

[static] char32_t QChar:: toTitleCase ( char32_t ucs4 )

这是重载函数。

Returns the title case equivalent of the UCS-4-encoded character specified by ucs4 if the character is lowercase or uppercase; otherwise returns the character itself.

注意: Before Qt 6, this function took a uint argument and returned uint .

QChar QChar:: toUpper () const

Returns the uppercase equivalent if the character is lowercase or titlecase; otherwise returns the character itself.

[static] char32_t QChar:: toUpper ( char32_t ucs4 )

这是重载函数。

Returns the uppercase equivalent of the UCS-4-encoded character specified by ucs4 if the character is lowercase or titlecase; otherwise returns the character itself.

注意: Before Qt 6, this function took a uint argument and returned uint .

char16_t QChar:: unicode () const

Returns the numeric Unicode value of the QChar .

char16_t &QChar:: unicode ()

Returns a reference to the numeric Unicode value of the QChar .

QChar::UnicodeVersion QChar:: unicodeVersion () const

Returns the Unicode version that introduced this character.

[static] QChar::UnicodeVersion QChar:: unicodeVersion ( char32_t ucs4 )

这是重载函数。

Returns the Unicode version that introduced the character specified in its UCS-4-encoded form as ucs4 .

注意: Before Qt 6, this function took a uint 自变量。

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bool operator!= ( QChar c1 , QChar c2 )

返回 true if c1 and c2 are not the same Unicode character; otherwise returns false .

bool operator< ( QChar c1 , QChar c2 )

返回 true if the numeric Unicode value of c1 is less than that of c2 ;否则返回 false .

QDataStream & operator<< ( QDataStream & out , QChar chr )

Writes the char chr 到流 out .

另请参阅 序列化 Qt 数据类型 .

bool operator<= ( QChar c1 , QChar c2 )

返回 true if the numeric Unicode value of c1 is less than or equal to that of c2 ;否则返回 false .

bool operator== ( QChar c1 , QChar c2 )

返回 true if c1 and c2 are the same Unicode character; otherwise returns false .

bool operator> ( QChar c1 , QChar c2 )

返回 true if the numeric Unicode value of c1 is greater than that of c2 ;否则返回 false .

bool operator>= ( QChar c1 , QChar c2 )

返回 true if the numeric Unicode value of c1 is greater than or equal to that of c2 ;否则返回 false .

QDataStream & operator>> ( QDataStream & in , QChar & chr )

Reads a char from the stream in into char chr .

另请参阅 序列化 Qt 数据类型 .

宏文档编制

[since 6.0] QT_IMPLICIT_QCHAR_CONSTRUCTION

Defining this macro makes certain QChar constructors implicit rather than explicit. This is done to enforce safe conversions:

QString str = getString();
if (str == 123) {
    // Oops, meant str == "123". By default does not compile,
    // *unless* this macro is defined, in which case, it's interpreted
    // as `if (str == QChar(123))`, that is, `if (str == '{')`.
    // Likely, not what we meant.
}
							

This macro is provided to keep existing code working; it is recommended to instead use explicit conversions and/or QLatin1Char . For instance:

QChar c1 =  'x'; // OK, unless QT_NO_CAST_FROM_ASCII is defined
QChar c2 = u'x'; // always OK, recommended
QChar c3 = QLatin1Char('x'); // always OK, recommended
// from int to 1 UTF-16 code unit: must guarantee that the input is <= 0xFFFF
QChar c4 = 120;        // compile error, unless QT_IMPLICIT_QCHAR_CONSTRUCTION is defined
QChar c5(120);         // OK (direct initialization)
auto  c6 = QChar(120); // ditto
// from int/char32_t to 1/2 UTF-16 code units:
// 𝄞 'MUSICAL SYMBOL G CLEF' (U+1D11E)
auto c7 = QChar(0x1D11E);           // compiles, but undefined behavior at runtime
auto c8 = QChar::fromUcs4(0x1D11E);       // always OK
auto c9 = QChar::fromUcs4(U'\U0001D11E'); // always OK
// => use c8/c9 as QStringView objects
							

该函数在 Qt 6.0 引入。

另请参阅 QLatin1Char , QChar::fromUcs4 ,和 QT_NO_CAST_FROM_ASCII .