The QLatin1StringView class provides a thin wrapper around a US-ASCII/Latin-1 encoded string literal. 更多...
| 头： | #include <QLatin1StringView> |
| CMake: |
find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core) |
| qmake: | QT += core |
注意： 此类的所有函数 可重入 .
| const_iterator | |
| const_reference | |
| const_reverse_iterator | |
| difference_type | |
| iterator | |
| reference | |
| reverse_iterator | |
| size_type | |
| value_type |
| QLatin1StringView () | |
| QLatin1StringView (std::nullptr_t) | |
| QLatin1StringView (const char * str ) | |
| QLatin1StringView (const char * first , const char * last ) | |
| QLatin1StringView (const char * str , qsizetype size ) | |
| QLatin1StringView (const QByteArray & str ) | |
| QLatin1StringView (QByteArrayView str ) | |
| QString | arg (Args &&... args ) const |
| QLatin1Char | at (qsizetype pos ) const |
| QLatin1Char | back () const |
| QLatin1StringView::const_iterator | begin () const |
| QLatin1StringView::const_iterator | cbegin () const |
| QLatin1StringView::const_iterator | cend () const |
| void | chop (qsizetype length ) |
| QLatin1StringView | chopped (qsizetype length ) const |
| int | compare (QStringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| int | compare (QLatin1StringView l1 , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| int | compare (QUtf8StringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| int | compare (QChar ch ) const |
| int | compare (QChar ch , Qt::CaseSensitivity cs ) const |
| const char * | constBegin () const |
| const char * | constData () const |
| const char * | constEnd () const |
| bool | contains (QStringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | contains (QLatin1StringView l1 , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | contains (QChar c , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | count (QStringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | count (QLatin1StringView l1 , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | count (QChar ch , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| QLatin1StringView::const_reverse_iterator | crbegin () const |
| QLatin1StringView::const_reverse_iterator | crend () const |
| const char * | data () const |
| bool | empty () const |
| QLatin1StringView::const_iterator | end () const |
| bool | endsWith (QStringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | endsWith (QLatin1StringView l1 , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | endsWith (QChar ch ) const |
| bool | endsWith (QChar ch , Qt::CaseSensitivity cs ) const |
| QLatin1Char | first () const |
| QLatin1StringView | first (qsizetype n ) const |
| QLatin1Char | front () const |
| qsizetype | indexOf (QStringView str , qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | indexOf (QLatin1StringView l1 , qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | indexOf (QChar c , qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | isEmpty () const |
| bool | isNull () const |
| QLatin1Char | last () const |
| QLatin1StringView | last (qsizetype n ) const |
| qsizetype | lastIndexOf (QStringView str , qsizetype from , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | lastIndexOf (QStringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | lastIndexOf (QLatin1StringView l1 , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | lastIndexOf (QLatin1StringView l1 , qsizetype from , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | lastIndexOf (QChar ch , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| qsizetype | lastIndexOf (QChar c , qsizetype from , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| const char * | latin1 () const |
| QLatin1StringView | left (qsizetype length ) const |
| qsizetype | length () const |
| QLatin1StringView | mid (qsizetype start , qsizetype length = -1) const |
| QLatin1StringView::const_reverse_iterator | rbegin () const |
| QLatin1StringView::const_reverse_iterator | rend () const |
| QLatin1StringView | right (qsizetype length ) const |
| qsizetype | size () const |
| QLatin1StringView | sliced (qsizetype pos ) const |
| QLatin1StringView | sliced (qsizetype pos , qsizetype n ) const |
| bool | startsWith (QStringView str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | startsWith (QLatin1StringView l1 , Qt::CaseSensitivity cs = Qt::CaseSensitive) const |
| bool | startsWith (QChar ch ) const |
| bool | startsWith (QChar ch , Qt::CaseSensitivity cs ) const |
| double | toDouble (bool * ok = nullptr) const |
| float | toFloat (bool * ok = nullptr) const |
| int | toInt (bool * ok = nullptr, int base = 10) const |
| long | toLong (bool * ok = nullptr, int base = 10) const |
| qlonglong | toLongLong (bool * ok = nullptr, int base = 10) const |
| short | toShort (bool * ok = nullptr, int base = 10) const |
| QString | toString () const |
| uint | toUInt (bool * ok = nullptr, int base = 10) const |
| ulong | toULong (bool * ok = nullptr, int base = 10) const |
| qulonglong | toULongLong (bool * ok = nullptr, int base = 10) const |
| ushort | toUShort (bool * ok = nullptr, int base = 10) const |
| decltype(qTokenize(*this, std::forward<Needle>(needle), flags...)) | tokenize (Needle && sep , Flags... flags ) const |
| QLatin1StringView | trimmed () const |
| void | truncate (qsizetype length ) |
| bool | operator!= (const char * other ) const |
| bool | operator!= (const QByteArray & other ) const |
| bool | operator< (const char * other ) const |
| bool | operator< (const QByteArray & other ) const |
| bool | operator<= (const char * other ) const |
| bool | operator<= (const QByteArray & other ) const |
| bool | operator== (const char * other ) const |
| bool | operator== (const QByteArray & other ) const |
| bool | operator> (const char * other ) const |
| bool | operator> (const QByteArray & other ) const |
| bool | operator>= (const char * other ) const |
| bool | operator>= (const QByteArray & other ) const |
| QLatin1Char | operator[] (qsizetype pos ) const |
| bool | operator!= (QLatin1StringView s1 , QLatin1StringView s2 ) |
| bool | operator!= (QChar ch , QLatin1StringView s ) |
| bool | operator!= (QLatin1StringView s , QChar ch ) |
| bool | operator!= (QStringView s1 , QLatin1StringView s2 ) |
| bool | operator!= (QLatin1StringView s1 , QStringView s2 ) |
| bool | operator!= (const char * s1 , QLatin1StringView s2 ) |
| QLatin1StringView | operator""_L1 (const char * str , size_t size ) |
| bool | operator< (QLatin1StringView s1 , QLatin1StringView s2 ) |
| bool | operator< (QChar ch , QLatin1StringView s ) |
| bool | operator< (QLatin1StringView s , QChar ch ) |
| bool | operator< (QStringView s1 , QLatin1StringView s2 ) |
| bool | operator< (QLatin1StringView s1 , QStringView s2 ) |
| bool | operator< (const char * s1 , QLatin1StringView s2 ) |
| bool | operator<= (QLatin1StringView s1 , QLatin1StringView s2 ) |
| bool | operator<= (QChar ch , QLatin1StringView s ) |
| bool | operator<= (QLatin1StringView s , QChar ch ) |
| bool | operator<= (QStringView s1 , QLatin1StringView s2 ) |
| bool | operator<= (QLatin1StringView s1 , QStringView s2 ) |
| bool | operator<= (const char * s1 , QLatin1StringView s2 ) |
| bool | operator== (QLatin1StringView s1 , QLatin1StringView s2 ) |
| bool | operator== (QChar ch , QLatin1StringView s ) |
| bool | operator== (QLatin1StringView s , QChar ch ) |
| bool | operator== (QStringView s1 , QLatin1StringView s2 ) |
| bool | operator== (QLatin1StringView s1 , QStringView s2 ) |
| bool | operator== (const char * s1 , QLatin1StringView s2 ) |
| bool | operator> (QLatin1StringView s1 , QLatin1StringView s2 ) |
| bool | operator> (QChar ch , QLatin1StringView s ) |
| bool | operator> (QLatin1StringView s , QChar ch ) |
| bool | operator> (QStringView s1 , QLatin1StringView s2 ) |
| bool | operator> (QLatin1StringView s1 , QStringView s2 ) |
| bool | operator> (const char * s1 , QLatin1StringView s2 ) |
| bool | operator>= (QLatin1StringView s1 , QLatin1StringView s2 ) |
| bool | operator>= (QChar ch , QLatin1StringView s ) |
| bool | operator>= (QLatin1StringView s , QChar ch ) |
| bool | operator>= (QStringView s1 , QLatin1StringView s2 ) |
| bool | operator>= (QLatin1StringView s1 , QStringView s2 ) |
| bool | operator>= (const char * s1 , QLatin1StringView s2 ) |
很多
QString
's member functions are overloaded to accept
const char *
而不是
QString
. This includes the copy constructor, the assignment operator, the comparison operators, and various other functions such as
insert
(),
append
()，和
prepend
(). Some of these functions are optimized to avoid constructing a
QString
对象为
const char *
data. For example, assuming
str
是
QString
,
if (str == "auto" || str == "extern" || str == "static" || str == "register") { ... }
is much faster than
if (str == QString("auto") || str == QString("extern") || str == QString("static") || str == QString("register")) { ... }
because it doesn't construct four temporary QString objects and make a deep copy of the character data.
However, that is not true for all
QString
member functions that take
const char *
and therefore applications should assume a temporary will be created, such as in
str.append("Hello ").append("World");
Applications that define
QT_NO_CAST_FROM_ASCII
(as explained in the
QString
documentation) don't have access to
QString
's
const char *
API. To provide an efficient way of specifying constant Latin-1 strings, Qt provides the QLatin1StringView, which is just a very thin wrapper around a
const char *
. Using QLatin1StringView, the example code above becomes
if (str == "auto"_L1 || str == "extern"_L1 || str == "static"_L1 || str == "register"_L1 { ... }
This is a bit longer to type, but it provides exactly the same benefits as the first version of the code, and is faster than converting the Latin-1 strings using QString::fromLatin1 ().
Thanks to the QString (QLatin1StringView) constructor, QLatin1StringView can be used everywhere a QString is expected. For example:
QLabel *label = new QLabel("MOD"_L1, this);
注意： If the function you're calling with a QLatin1StringView argument isn't actually overloaded to take QLatin1StringView, the implicit conversion to QString will trigger a memory allocation, which is usually what you want to avoid by using QLatin1StringView in the first place. In those cases, using QStringLiteral may be the better option.
另请参阅 QString , QLatin1Char , QStringLiteral ，和 QT_NO_CAST_FROM_ASCII .
[alias]
QLatin1StringView::
const_iterator
另请参阅 iterator and const_reverse_iterator .
[alias]
QLatin1StringView::
const_reference
别名化的
reference
。为兼容 STL (标准模板库) 提供。
[alias]
QLatin1StringView::
const_reverse_iterator
另请参阅 reverse_iterator and const_iterator .
[alias]
QLatin1StringView::
difference_type
别名化的
qsizetype
。为兼容 STL (标准模板库) 提供。
[alias]
QLatin1StringView::
iterator
QLatin1StringView does not support mutable iterators, so this is the same as const_iterator.
另请参阅 const_iterator and reverse_iterator .
[alias]
QLatin1StringView::
reference
别名化的
value_type &
。为兼容 STL (标准模板库) 提供。
[alias]
QLatin1StringView::
reverse_iterator
QLatin1StringView does not support mutable reverse iterators, so this is the same as const_reverse_iterator.
另请参阅 const_reverse_iterator and iterator .
[alias]
QLatin1StringView::
size_type
别名化的
qsizetype
。为兼容 STL (标准模板库) 提供。
注意：
In version prior to Qt 6, this was an alias for
int
, restricting the amount of data that could be held in a
QLatin1StringView
on 64-bit architectures.
[alias]
QLatin1StringView::
value_type
别名化的
const char
。为兼容 STL (标准模板库) 提供。
[constexpr]
int
QLatin1StringView::
compare
(
QChar
ch
) const
Returns an integer that compares to zero as this string view compares to the UTF-16 string viewed by str , the Latin-1 string viewed by l1 , or the character ch ，分别。
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
另请参阅 operator== (), operator< ()，和 operator> ().
[constexpr]
bool
QLatin1StringView::
startsWith
(
QChar
ch
) const
返回
true
if this Latin-1 string view starts with the UTF-16 string viewed by
str
, the Latin-1 string viewed by
l1
, or the character
ch
, respectively; otherwise returns
false
.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
另请参阅 endsWith ().
[constexpr]
bool
QLatin1StringView::
endsWith
(
QChar
ch
) const
返回
true
if this Latin-1 string view ends with the UTF-16 string viewed
str
, the Latin-1 string viewed by
l1
, or the character
ch
, respectively; otherwise returns
false
.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
另请参阅 startsWith ().
Returns the index position in this Latin-1 string view of the first occurrence of the UTF-16 string viewed by str , the Latin-1 string viewed by l1 , or the character ch , respectively, searching forward from index position from . Returns -1 if str , l1 or c is not found, respectively.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
若 from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.
另请参阅 QString::indexOf ().
返回
true
if this Latin-1 string view contains an occurrence of the UTF-16 string viewed by
str
, the Latin-1 string viewed by
l1
, or the character
ch
, respectively; otherwise returns
false
.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
另请参阅 indexOf (), QStringView::contains (), QStringView::indexOf ()，和 QString::indexOf ().
Returns the index position in this Latin-1 string view of the last occurrence of the UTF-16 string viewed by str , the Latin-1 string viewed by l1 , or the character ch , respectively, searching backward from index position from ; returns -1 if str , l1 or ch is not found, respectively.
若 from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
注意：
When searching for a 0-length
str
or
l1
, the match at the end of the data is excluded from the search by a negative
from
, even though
-1
is normally thought of as searching from the end of the string: the match at the end is
after
the last character, so it is excluded. To include such a final empty match, either give a positive value for
from
or omit the
from
parameter entirely.
另请参阅 indexOf (), QStringView::lastIndexOf (), QStringView::indexOf ()，和 QString::indexOf ().
[since 6.2]
qsizetype
QLatin1StringView::
lastIndexOf
(
QLatin1StringView
l1
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
[since 6.2]
qsizetype
QLatin1StringView::
lastIndexOf
(
QStringView
str
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
此函数重载 lastIndexOf ().
Returns the index position in this Latin-1 string view of the last occurrence of the UTF-16 string viewed by str or the Latin-1 string viewed by l1 , respectively. Returns -1 if str or l1 is not found, respectively.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
该函数在 Qt 6.2 引入。
[since 6.4]
qsizetype
QLatin1StringView::
count
(
QChar
ch
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
[since 6.4]
qsizetype
QLatin1StringView::
count
(
QLatin1StringView
l1
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
[since 6.4]
qsizetype
QLatin1StringView::
count
(
QStringView
str
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
Returns the number of (potentially overlapping) occurrences of the UTF-16 string viewed by str , the Latin-1 string viewed by l1 , or the character ch , respectively, in this string view.
若 cs is Qt::CaseSensitive (默认)，搜索区分大小写；否则，搜索不区分大小写。
该函数在 Qt 6.4 引入。
另请参阅 contains () 和 indexOf ().
[since 6.4]
int
QLatin1StringView::
toInt
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
long
QLatin1StringView::
toLong
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
qlonglong
QLatin1StringView::
toLongLong
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
qulonglong
QLatin1StringView::
toULongLong
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
short
QLatin1StringView::
toShort
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
uint
QLatin1StringView::
toUInt
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
ulong
QLatin1StringView::
toULong
(
bool
*
ok
= nullptr,
int
base
= 10) const
[since 6.4]
ushort
QLatin1StringView::
toUShort
(
bool
*
ok
= nullptr,
int
base
= 10) const
Returns this QLatin1StringView converted to a corresponding numeric value using base base , which is ten by default. Bases 0 and 2 through 36 are supported, using letters for digits beyond 9; A is ten, B is eleven and so on.
若 base is 0, the base is determined automatically using the following rules (in this order), if the Latin-1 string view begins with:
"0x"
, the rest of it is read as hexadecimal (base 16)
"0b"
, the rest of it is read as binary (base 2)
"0"
, the rest of it is read as octal (base 8)
返回 0，若转换失败。
若
ok
不是
nullptr
, failure is reported by setting *
ok
to
false
, and success by setting *
ok
to
true
.
注意： The conversion of the number is performed in the default C locale, regardless of the user's locale. Use QLocale to perform locale-aware conversions between numbers and strings.
This function ignores leading and trailing spacing characters.
注意： 在 Qt 6.4 添加对 0b 前缀的支持。
该函数在 Qt 6.4 引入。
[since 6.4]
double
QLatin1StringView::
toDouble
(
bool
*
ok
= nullptr) const
[since 6.4]
float
QLatin1StringView::
toFloat
(
bool
*
ok
= nullptr) const
Returns this QLatin1StringView converted to a corresponding floating-point value.
Returns an infinity if the conversion overflows or 0.0 if the conversion fails for other reasons (e.g. underflow).
若
ok
不是
nullptr
, failure is reported by setting *
ok
to
false
, and success by setting *
ok
to
true
.
警告： The QLatin1StringView content may only contain valid numerical characters which includes the plus/minus sign, the character e used in scientific notation, and the decimal point. Including the unit or additional characters leads to a conversion error.
注意： The conversion of the number is performed in the default C locale, regardless of the user's locale. Use QLocale to perform locale-aware conversions between numbers and strings.
This function ignores leading and trailing spacing characters.
该函数在 Qt 6.4 引入。
Replaces occurrences of
%N
in this string with the corresponding argument from
args
. The arguments are not positional: the first of the
args
替换
%N
with the lowest
N
(all of them), the second of the
args
the
%N
with the next-lowest
N
etc.
Args
can consist of anything that implicitly converts to
QString
,
QStringView
or
QLatin1StringView
.
In addition, the following types are also supported: QChar , QLatin1Char .
另请参阅 QString::arg ().
[constexpr, since 6.0]
template <typename Needle, typename Flags>
decltype
(
qTokenize
(*
this
,
std::forward
<
Needle
>(
needle
),
flags
...)) QLatin1StringView::
tokenize
(
Needle
&&
sep
,
Flags
...
flags
) const
Splits the string into substring views wherever sep occurs, and returns a lazy sequence of those strings.
相当于
return QStringTokenizer{std::forward<Needle>(sep), flags...};
except it works without C++17 Class Template Argument Deduction (CTAD) enabled in the compiler.
见 QStringTokenizer for how sep and flags interact to form the result.
注意： While this function returns QStringTokenizer , you should never, ever, name its template arguments explicitly. If you can use C++17 Class Template Argument Deduction (CTAD), you may write
QStringTokenizer result = sv.tokenize(sep);
(without template arguments). If you can't use C++17 CTAD, you must store the return value only in
auto
变量：
auto result = sv.tokenize(sep);
This is because the template arguments of QStringTokenizer have a very subtle dependency on the specific tokenize () overload from which they are returned, and they don't usually correspond to the type used for the separator.
该函数在 Qt 6.0 引入。
另请参阅 QStringTokenizer and qTokenize ().
[constexpr]
QLatin1StringView::
QLatin1StringView
()
Constructs a QLatin1StringView object that stores a
nullptr
.
另请参阅 data (), isEmpty (), isNull ()，和 null 和空字符串之间的区别 .
[constexpr, since 6.4]
QLatin1StringView::
QLatin1StringView
(
std::nullptr_t
)
Constructs a QLatin1StringView object that stores a
nullptr
.
该函数在 Qt 6.4 引入。
另请参阅 data (), isEmpty (), isNull ()，和 null 和空字符串之间的区别 .
[explicit constexpr]
QLatin1StringView::
QLatin1StringView
(const
char
*
str
)
Constructs a QLatin1StringView object that stores str .
The string data is not copied. The caller must be able to guarantee that str will not be deleted or modified as long as the QLatin1StringView object exists.
另请参阅 latin1 ().
[constexpr]
QLatin1StringView::
QLatin1StringView
(const
char
*
first
, const
char
*
last
)
Constructs a QLatin1StringView object that stores first 按长度 ( last - first ).
范围
[first,last)
must remain valid for the lifetime of this Latin-1 string object.
传递
nullptr
as
first
是安全的若
last
is
nullptr
, too, and results in a null Latin-1 string.
行为未定义若
last
precedes
first
,
first
is
nullptr
and
last
is not, or if
last - first > INT_MAX
.
[constexpr]
QLatin1StringView::
QLatin1StringView
(const
char
*
str
,
qsizetype
size
)
Constructs a QLatin1StringView object that stores str with size .
The string data is not copied. The caller must be able to guarantee that str will not be deleted or modified as long as the QLatin1StringView object exists.
注意： : any null ('\0') bytes in the byte array will be included in this string, which will be converted to Unicode null characters (U+0000) if this string is used by QString . This behavior is different from Qt 5.x.
另请参阅 latin1 ().
[explicit]
QLatin1StringView::
QLatin1StringView
(const
QByteArray
&
str
)
Constructs a QLatin1StringView object as a view on str .
The string data is not copied. The caller must be able to guarantee that str will not be deleted or modified as long as the QLatin1StringView object exists.
另请参阅 latin1 ().
[explicit constexpr, since 6.3]
QLatin1StringView::
QLatin1StringView
(
QByteArrayView
str
)
Constructs a QLatin1StringView object as a view on str .
The string data is not copied. The caller must be able to guarantee that the data which str is pointing to will not be deleted or modified as long as the QLatin1StringView object exists. The size is obtained from str as-is, without checking for a null-terminator.
注意： : any null ('\0') bytes in the byte array will be included in this string, which will be converted to Unicode null characters (U+0000) if this string is used by QString .
该函数在 Qt 6.3 引入。
另请参阅 latin1 ().
[constexpr]
QLatin1Char
QLatin1StringView::
at
(
qsizetype
pos
) const
返回字符位于位置 pos 在此对象。
注意： This function performs no error checking. The behavior is undefined when pos < 0 or pos >= size ().
另请参阅 operator[] ().
[constexpr]
QLatin1Char
QLatin1StringView::
back
() const
返回字符串中的最后一个字符。如同
at(size() - 1)
.
此函数为兼容 STL (标准模板库) 提供。
警告： 在空字符串调用此函数，将构成未定义行为。
另请参阅 front (), at ()，和 operator[] ().
[constexpr]
QLatin1StringView::const_iterator
QLatin1StringView::
begin
() const
返回常量 STL 样式迭代器 指向字符串中的首个字符。
此函数为兼容 STL (标准模板库) 提供。
另请参阅 end (), cbegin (), rbegin ()，和 data ().
[constexpr]
QLatin1StringView::const_iterator
QLatin1StringView::
cbegin
() const
如同 begin ().
此函数为兼容 STL (标准模板库) 提供。
另请参阅 cend (), begin (), crbegin ()，和 data ().
[constexpr]
QLatin1StringView::const_iterator
QLatin1StringView::
cend
() const
如同 end ().
此函数为兼容 STL (标准模板库) 提供。
另请参阅 cbegin (), end ()，和 crend ().
[constexpr]
void
QLatin1StringView::
chop
(
qsizetype
length
)
Truncates this string by length 字符。
如同
*this = left(size() - length)
.
注意： 行为未定义当 length < 0 or length > size ().
另请参阅 sliced (), first (), last (), chopped ()，和 truncate ().
[constexpr]
QLatin1StringView
QLatin1StringView::
chopped
(
qsizetype
length
) const
返回子字符串长度 size () - length 起始于此对象的开头。
如同
left(size() - length)
.
注意： 行为未定义当 length < 0 or length > size ().
另请参阅 sliced (), first (), last (), chop ()，和 truncate ().
[since 6.5]
int
QLatin1StringView::
compare
(
QUtf8StringView
str
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
Returns an integer that compares to zero as this string view compares to the string view str .
若 cs is Qt::CaseSensitive (默认)，比较区分大小写；否则，比较不区分大小写。
该函数在 Qt 6.5 引入。
另请参阅 operator== (), operator< ()，和 operator> ().
[constexpr, since 6.4]
const
char
*QLatin1StringView::
constBegin
() const
如同 begin ().
This function is provided for compatibility with other Qt containers.
该函数在 Qt 6.4 引入。
另请参阅 constEnd (), begin (), cbegin ()，和 data ().
[constexpr, since 6.4]
const
char
*QLatin1StringView::
constData
() const
Returns the start of the Latin-1 string referenced by this object.
This function is provided for compatibility with other Qt containers.
该函数在 Qt 6.4 引入。
另请参阅 data ().
[constexpr, since 6.4]
const
char
*QLatin1StringView::
constEnd
() const
如同 end ().
This function is provided for compatibility with other Qt containers.
该函数在 Qt 6.4 引入。
另请参阅 constBegin (), end (), cend ()，和 crend ().
如同 rbegin ().
此函数为兼容 STL (标准模板库) 提供。
另请参阅 crend (), rbegin ()，和 cbegin ().
如同 rend ().
此函数为兼容 STL (标准模板库) 提供。
另请参阅 crbegin (), rend ()，和 cend ().
[constexpr]
const
char
*QLatin1StringView::
data
() const
Returns the start of the Latin-1 string referenced by this object.
[constexpr, since 6.4]
bool
QLatin1StringView::
empty
() const
Returns whether the Latin-1 string referenced by this object is empty (
size() == 0
) or not.
此函数为兼容 STL (标准模板库) 提供。
该函数在 Qt 6.4 引入。
另请参阅 isEmpty (), isNull ()，和 size ().
[constexpr]
QLatin1StringView::const_iterator
QLatin1StringView::
end
() const
返回常量 STL 样式迭代器 仅仅指向字符串中最后一个字符的后面。
此函数为兼容 STL (标准模板库) 提供。
另请参阅 begin (), cend ()，和 rend ().
[constexpr, since 6.4]
QLatin1Char
QLatin1StringView::
first
() const
Returns the first character in the string. Same as
at(0)
or
front
().
This function is provided for compatibility with other Qt containers.
警告： 在空字符串调用此函数，将构成未定义行为。
该函数在 Qt 6.4 引入。
另请参阅 last (), front ()，和 back ().
[constexpr, since 6.0]
QLatin1StringView
QLatin1StringView::
first
(
qsizetype
n
) const
Returns a Latin-1 string view that contains the first n characters of this string view.
注意： 行为未定义当 n < 0 or n > size ().
该函数在 Qt 6.0 引入。
另请参阅 last (), startsWith (), chopped (), chop ()，和 truncate ().
[constexpr]
QLatin1Char
QLatin1StringView::
front
() const
Returns the first character in the string. Same as
at(0)
.
此函数为兼容 STL (标准模板库) 提供。
警告： 在空字符串调用此函数，将构成未定义行为。
另请参阅 back (), at ()，和 operator[] ().
[constexpr]
bool
QLatin1StringView::
isEmpty
() const
Returns whether the Latin-1 string referenced by this object is empty (
size() == 0
) or not.
[constexpr]
bool
QLatin1StringView::
isNull
() const
Returns whether the Latin-1 string referenced by this object is null (
data() == nullptr
) or not.
[constexpr, since 6.4]
QLatin1Char
QLatin1StringView::
last
() const
返回字符串中的最后一个字符。如同
at(size() - 1)
or
back
().
This function is provided for compatibility with other Qt containers.
警告： 在空字符串调用此函数，将构成未定义行为。
该函数在 Qt 6.4 引入。
另请参阅 first (), back ()，和 front ().
[constexpr, since 6.0]
QLatin1StringView
QLatin1StringView::
last
(
qsizetype
n
) const
Returns a Latin-1 string view that contains the last n characters of this string view.
注意： 行为未定义当 n < 0 or n > size ().
该函数在 Qt 6.0 引入。
另请参阅 first (), endsWith (), chopped (), chop ()，和 truncate ().
[since 6.3]
qsizetype
QLatin1StringView::
lastIndexOf
(
QChar
ch
,
Qt::CaseSensitivity
cs
= Qt::CaseSensitive) const
这是重载函数。
该函数在 Qt 6.3 引入。
[constexpr]
const
char
*QLatin1StringView::
latin1
() const
Returns the start of the Latin-1 string referenced by this object.
[constexpr]
QLatin1StringView
QLatin1StringView::
left
(
qsizetype
length
) const
若知道 length 不可以超出边界，使用 first () 代替在新代码中，因为它更快。
返回子字符串长度 length starting at position 0 in this Latin-1 string view.
The entire Latin-1 string view is returned if length >= size ()，或小于 0。
另请参阅 first (), last (), sliced (), startsWith (), chopped (), chop ()，和 truncate ().
[constexpr, since 6.4]
qsizetype
QLatin1StringView::
length
() const
如同 size ().
This function is provided for compatibility with other Qt containers.
该函数在 Qt 6.4 引入。
[constexpr]
QLatin1StringView
QLatin1StringView::
mid
(
qsizetype
start
,
qsizetype
length
= -1) const
返回子字符串长度 length 起始于位置 start in this Latin-1 string view.
若知道 start and length 不可以超出边界，使用 sliced () 代替在新代码中，因为它更快。
Returns an empty Latin-1 string view if start exceeds the length of this string view. If there are less than length characters available in this string view starting at start ，或者若 length is negative (default), the function returns all characters that are available from start .
另请参阅 first (), last (), sliced (), chopped (), chop ()，和 truncate ().
返回常量 STL-style reverse iterator pointing to the first character in the string, in reverse order.
此函数为兼容 STL (标准模板库) 提供。
另请参阅 rend (), crbegin ()，和 begin ().
返回 STL-style reverse iterator pointing just after the last character in the string, in reverse order.
此函数为兼容 STL (标准模板库) 提供。
另请参阅 rbegin (), crend ()，和 end ().
[constexpr]
QLatin1StringView
QLatin1StringView::
right
(
qsizetype
length
) const
若知道 length 不可以超出边界，使用 last () 代替在新代码中，因为它更快。
返回子字符串长度 length 起始于位置 size () - length in this Latin-1 string view.
The entire Latin-1 string view is returned if length >= size ()，或小于 0。
另请参阅 first (), last (), sliced (), endsWith (), chopped (), chop ()，和 truncate ().
[constexpr]
qsizetype
QLatin1StringView::
size
() const
Returns the size of the Latin-1 string referenced by this object.
注意：
In version prior to Qt 6, this function returned
int
, restricting the amount of data that could be held in a
QLatin1StringView
on 64-bit architectures.
[constexpr, since 6.0]
QLatin1StringView
QLatin1StringView::
sliced
(
qsizetype
pos
) const
Returns a Latin-1 string view starting at position pos in this string view, and extending to its end.
注意： 行为未定义当 pos < 0 or pos > size ().
该函数在 Qt 6.0 引入。
另请参阅 first (), last (), chopped (), chop ()，和 truncate ().
[constexpr, since 6.0]
QLatin1StringView
QLatin1StringView::
sliced
(
qsizetype
pos
,
qsizetype
n
) const
Returns a Latin-1 string view that points to n characters of this string view, starting at position pos .
注意：
行为未定义当
pos
< 0,
n
< 0, or
pos + n > size()
.
该函数在 Qt 6.0 引入。
另请参阅 first (), last (), chopped (), chop ()，和 truncate ().
[since 6.0]
QString
QLatin1StringView::
toString
() const
Converts this Latin-1 string into a QString . Equivalent to
return QString(*this);
该函数在 Qt 6.0 引入。
Strips leading and trailing whitespace and returns the result.
空白意味着任何字符其。
QChar::isSpace
() 返回
true
。这包括 ASCII 字符 \t、\n、\v、\f、\r、及 " "。
[constexpr]
void
QLatin1StringView::
truncate
(
qsizetype
length
)
Truncates this string to length length .
如同
*this = left(length)
.
注意： 行为未定义当 length < 0 or length > size ().
另请参阅 sliced (), first (), last (), chopped ()，和 chop ().
返回
true
if this string is not equal to const char pointer
other
；否则返回
false
.
The other const char pointer is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
另请参阅 Comparing Strings .
This function overloads operator!=().
The other byte array is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
返回
true
if this string is lexically less than const char pointer
other
；否则返回
false
.
The other const char pointer is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
另请参阅 Comparing Strings .
这是重载函数。
The other byte array is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
返回
true
if this string is lexically less than or equal to const char pointer
other
；否则返回
false
.
The other const char pointer is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
另请参阅 Comparing Strings .
这是重载函数。
The other byte array is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
返回
true
if the string is equal to const char pointer
other
；否则返回
false
.
The other const char pointer is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
另请参阅 Comparing Strings .
这是重载函数。
The other byte array is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
返回
true
if this string is lexically greater than const char pointer
other
；否则返回
false
.
The other const char pointer is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
另请参阅 Comparing Strings .
这是重载函数。
The other byte array is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
返回
true
if this string is lexically greater than or equal to const char pointer
other
；否则返回
false
.
The other const char pointer is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
另请参阅 Comparing Strings .
这是重载函数。
The other byte array is converted to a QString 使用 QString::fromUtf8 () 函数。
可以禁用此运算符通过定义 QT_NO_CAST_FROM_ASCII when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through QObject::tr (), for example.
[constexpr]
QLatin1Char
QLatin1StringView::
operator[]
(
qsizetype
pos
) const
返回字符位于位置 pos 在此对象。
注意： This function performs no error checking. The behavior is undefined when pos < 0 or pos >= size ().
另请参阅 at ().
返回
true
若字符串
s1
is lexically not equal to string
s2
；否则返回
false
.
返回
true
if char
ch
is lexically not equal to string
s
；否则返回
false
.
返回
true
若字符串
s
is lexically not equal to char
ch
；否则返回
false
.
返回
true
if string view
s1
is lexically not equal to string
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically not equal to string view
s2
；否则返回
false
.
返回
true
if const char pointer
s1
is lexically not equal to string
s2
；否则返回
false
.
[constexpr, since 6.4]
QLatin1StringView
operator""_L1
(const
char
*
str
,
size_t
size
)
文字运算符创建的 QLatin1StringView out of the first size characters in the char string literal str .
以下代码创建 QLatin1StringView :
using namespace Qt::Literals::StringLiterals; auto str = "hello"_L1;
该函数在 Qt 6.4 引入。
另请参阅 Qt::Literals::StringLiterals .
返回
true
若字符串
s1
词法上小于字符串
s2
；否则返回
false
.
返回
true
if char
ch
词法上小于字符串
s
；否则返回
false
.
返回
true
若字符串
s
is lexically less than char
ch
；否则返回
false
.
返回
true
if string view
s1
词法上小于字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically less than string view
s2
；否则返回
false
.
返回
true
if const char pointer
s1
词法上小于字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
词法上 <= 字符串
s2
；否则返回
false
.
返回
true
if char
ch
词法上 <= 字符串
s
；否则返回
false
.
返回
true
若字符串
s
is lexically less than or equal to char
ch
；否则返回
false
.
返回
true
if string view
s1
词法上 <= 字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically less than or equal to string view
s2
；否则返回
false
.
返回
true
if const char pointer
s1
词法上 <= 字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically equal to string
s2
；否则返回
false
.
返回
true
if char
ch
is lexically equal to string
s
；否则返回
false
.
返回
true
若字符串
s
is lexically equal to char
ch
；否则返回
false
.
返回
true
if string view
s1
is lexically equal to string
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically equal to string view
s2
；否则返回
false
.
返回
true
if const char pointer
s1
is lexically equal to string
s2
；否则返回
false
.
返回
true
若字符串
s1
词法上大于字符串
s2
；否则返回
false
.
返回
true
if char
ch
词法上大于字符串
s
；否则返回
false
.
返回
true
若字符串
s
is lexically greater than char
ch
；否则返回
false
.
返回
true
if string view
s1
词法上大于字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically greater than string view
s2
；否则返回
false
.
返回
true
if const char pointer
s1
词法上大于字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
词法上大于等于字符串
s2
；否则返回
false
.
返回
true
if char
ch
词法上大于等于字符串
s
；否则返回
false
.
返回
true
若字符串
s
is lexically greater than or equal to char
ch
；否则返回
false
.
返回
true
if string view
s1
词法上大于等于字符串
s2
；否则返回
false
.
返回
true
若字符串
s1
is lexically greater than or equal to string view
s2
；否则返回
false
.
返回
true
if const char pointer
s1
词法上大于等于字符串
s2
；否则返回
false
.