QStringList 類

The QStringList class provides a list of strings. 更多...

頭: #include <QStringList>
繼承: QList<QString>

注意: 此類的所有函數 可重入 .

公共函數

QStringList ()
QStringList (const QString & str )
QStringList (const QStringList & other )
QStringList (const QList<QString> & other )
QStringList (std::initializer_list<QString> args )
bool contains (const QString & str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const
QStringList filter (const QString & str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const
QStringList filter (const QRegExp & rx ) const
int indexOf (const QRegExp & rx , int from = 0) const
int indexOf (const QString & value , int from = 0) const
int indexOf (QRegExp & rx , int from = 0) const
QString join (const QString & separator ) const
int lastIndexOf (const QRegExp & rx , int from = -1) const
int lastIndexOf (const QString & value , int from = -1) const
int lastIndexOf (QRegExp & rx , int from = -1) const
int removeDuplicates ()
QStringList & replaceInStrings (const QString & before , const QString & after , Qt::CaseSensitivity cs = Qt::CaseSensitive)
QStringList & replaceInStrings (const QRegExp & rx , const QString & after )
void sort ()
QStringList operator+ (const QStringList & other ) const
QStringList & operator<< (const QString & str )
QStringList & operator<< (const QStringList & other )
  • 68 public functions inherited from QList
typedef QMutableStringListIterator
typedef QStringListIterator
QDataStream & operator<< (QDataStream & out , const QStringList & list )
QDataStream & operator>> (QDataStream & in , QStringList & list )

額外繼承成員

  • 3 static public members inherited from QList

詳細描述

The QStringList class provides a list of strings.

QStringList 繼承自 QList < QString >。像 QList , QStringList is 隱式共享 。它提供快速基於索引的訪問,及快速插入和移除。以值參數形式傳遞字符串列錶,既快又安全。

所有的 QList 's functionality also applies to QStringList . For example, you can use isEmpty () 來測試列錶是否為空,可以調用函數像 append (), prepend (), insert (), replace (), removeAll (), removeAt (), removeFirst (), removeLast (),和 removeOne () to modify a QStringList . In addition, QStringList provides a few convenience functions that make handling lists of strings easier:

Adding strings

Strings can be added to a list using the append() , operator+= () 和 operator<< () functions. For example:

    QStringList fonts;
    fonts << "Arial" << "Helvetica" << "Times" << "Courier";
					

Iterating over the strings

To iterate over a list, you can either use index positions or QList 's Java-style and STL-style iterator types:

索引:

    for (int i = 0; i < fonts.size(); ++i)
         cout << fonts.at(i).toLocal8Bit().constData() << endl;
					

Java 風格迭代器:

    QStringListIterator javaStyleIterator(fonts);
    while (javaStyleIterator.hasNext())
         cout << javaStyleIterator.next().toLocal8Bit().constData() << endl;
					

STL 樣式迭代器:

    QStringList::const_iterator constIterator;
    for (constIterator = fonts.constBegin(); constIterator != fonts.constEnd();
           ++constIterator)
        cout << (*constIterator).toLocal8Bit().constData() << endl;
					

The QStringListIterator class is simply a type definition for QListIterator < QString >. QStringList 還提供 QMutableStringListIterator class which is a type definition for QMutableListIterator < QString >.

Manipulating the strings

QStringList provides several functions allowing you to manipulate the contents of a list. You can concatenate all the strings in a string list into a single string (with an optional separator) using the join () 函數。例如:

    QString str = fonts.join(",");
     // str == "Arial,Helvetica,Times,Courier"
					

To break up a string into a string list, use the QString::split () 函數:

    QStringList list;
    list = str.split(",");
     // list: ["Arial", "Helvetica", "Times", "Courier"]
					

The argument to split can be a single character, a string, or a QRegExp .

此外, operator+ () function allows you to concatenate two string lists into one. To sort a string list, use the sort () 函數。

QString 列錶還提供 filter () function which lets you to extract a new list which contains only those strings which contain a particular substring (or match a particular regular expression):

    QStringList monospacedFonts = fonts.filter(QRegExp("Courier|Fixed"));
					

The contains () function tells you whether the list contains a given string, while the indexOf () function returns the index of the first occurrence of the given string. The lastIndexOf () function on the other hand, returns the index of the last occurrence of the string.

Finally, the replaceInStrings () 函數調用 QString::replace () on each string in the string list in turn. For example:

    QStringList files;
    files << "$QTDIR/src/moc/moc.y"
          << "$QTDIR/src/moc/moc.l"
          << "$QTDIR/include/qconfig.h";
    files.replaceInStrings("$QTDIR", "/usr/lib/qt");
    // files: [ "/usr/lib/qt/src/moc/moc.y", ...]
					

另請參閱 QString .

成員函數文檔編製

QStringList:: QStringList ()

Constructs an empty string list.

QStringList:: QStringList (const QString & str )

Constructs a string list that contains the given string, str . Longer lists are easily created like this:

    QStringList longerList = (QStringList() << str1 << str2 << str3);
					

另請參閱 append ().

QStringList:: QStringList (const QStringList & other )

構造副本為 other string list.

此操作花費 常量時間 因為 QStringList is 隱式共享 , making the process of returning a QStringList from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes 綫性時間 .

另請參閱 operator= ().

QStringList:: QStringList (const QList < QString > & other )

構造副本為 other .

此操作花費 常量時間 ,因為 QStringList is 隱式共享 . This makes returning a QStringList from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes 綫性時間 .

另請參閱 operator= ().

QStringList:: QStringList ( std::initializer_list < QString > args )

Construct a list from a std::initializer_list given by args .

This constructor is only enabled if the compiler supports C++0x

該函數在 Qt 4.8 引入。

bool QStringList:: contains (const QString & str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const

Returns true if the list contains the string str ; otherwise returns false. The search is case insensitive if cs is Qt::CaseInsensitive ;搜索區分大小寫,默認情況下。

另請參閱 indexOf (), lastIndexOf (),和 QString::contains ().

QStringList QStringList:: filter (const QString & str , Qt::CaseSensitivity cs = Qt::CaseSensitive) const

返迴所有字符串的列錶包含子字符串 str .

cs is Qt::CaseSensitive (the default), the string comparison is case sensitive; otherwise the comparison is case insensitive.

    QStringList list;
    list << "Bill Murray" << "John Doe" << "Bill Clinton";
    QStringList result;
    result = list.filter("Bill");
    // result: ["Bill Murray", "Bill Clinton"]
					

這相當於

    QStringList result;
    foreach (const QString &str, list) {
        if (str.contains("Bill"))
            result += str;
    }
					

另請參閱 contains ().

QStringList QStringList:: filter (const QRegExp & rx ) const

這是重載函數。

Returns a list of all the strings that match the regular expression rx .

int QStringList:: indexOf (const QRegExp & rx , int from = 0) const

Returns the index position of the first exact match of rx in the list, searching forward from index position from . Returns -1 if no item matched.

By default, this function is case sensitive.

另請參閱 lastIndexOf (), contains (),和 QRegExp::exactMatch ().

int QStringList:: indexOf (const QString & value , int from = 0) const

Returns the index position of the first occurrence of value in the list, searching forward from index position from . Returns -1 if no item matched.

另請參閱 lastIndexOf (), contains (),和 QList::indexOf ().

int QStringList:: indexOf ( QRegExp & rx , int from = 0) const

此函數重載 indexOf ().

Returns the index position of the first exact match of rx in the list, searching forward from index position from . Returns -1 if no item matched.

By default, this function is case sensitive.

If an item matched, the rx regular expression will contain the matched objects (see QRegExp::matchedLength , QRegExp::cap ).

該函數在 Qt 4.5 引入。

另請參閱 lastIndexOf (), contains (),和 QRegExp::exactMatch ().

QString QStringList:: join (const QString & separator ) const

Joins all the string list's strings into a single string with each element separated by the given separator (which can be an empty string).

另請參閱 QString::split ().

int QStringList:: lastIndexOf (const QRegExp & rx , int from = -1) const

Returns the index position of the last exact match of rx in the list, searching backward from index position from 。若 from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

另請參閱 indexOf (), contains (),和 QRegExp::exactMatch ().

int QStringList:: lastIndexOf (const QString & value , int from = -1) const

Returns the index position of the last occurrence of value in the list, searching backward from index position from 。若 from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

另請參閱 indexOf () 和 QList::lastIndexOf ().

int QStringList:: lastIndexOf ( QRegExp & rx , int from = -1) const

此函數重載 lastIndexOf ().

Returns the index position of the last exact match of rx in the list, searching backward from index position from 。若 from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

If an item matched, the rx regular expression will contain the matched objects (see QRegExp::matchedLength , QRegExp::cap ).

該函數在 Qt 4.5 引入。

另請參閱 indexOf (), contains (),和 QRegExp::exactMatch ().

int QStringList:: removeDuplicates ()

This function removes duplicate entries from a list. The entries do not have to be sorted. They will retain their original order.

Returns the number of removed entries.

該函數在 Qt 4.5 引入。

QStringList & QStringList:: replaceInStrings (const QString & before , const QString & after , Qt::CaseSensitivity cs = Qt::CaseSensitive)

Returns a string list where every string has had the before text replaced with the after text wherever the before text is found. The before text is matched case-sensitively or not depending on the cs 標誌。

例如:

    QStringList list;
    list << "alpha" << "beta" << "gamma" << "epsilon";
    list.replaceInStrings("a", "o");
    // list == ["olpho", "beto", "gommo", "epsilon"]
					

另請參閱 QString::replace ().

QStringList & QStringList:: replaceInStrings (const QRegExp & rx , const QString & after )

這是重載函數。

Replaces every occurrence of the regexp rx , in each of the string lists's strings, with after . Returns a reference to the string list.

例如:

    QStringList list;
    list << "alpha" << "beta" << "gamma" << "epsilon";
    list.replaceInStrings(QRegExp("^a"), "o");
    // list == ["olpha", "beta", "gamma", "epsilon"]
					

For regular expressions that contain capturing parentheses , occurrences of \1 , \2 , ..., in after are replaced with rx .cap(1), rx .cap(2), ...

例如:

    QStringList list;
    list << "Bill Clinton" << "Murray, Bill";
    list.replaceInStrings(QRegExp("^(.*), (.*)$"), "\\2 \\1");
    // list == ["Bill Clinton", "Bill Murray"]
					

void QStringList:: sort ()

Sorts the list of strings in ascending order (case sensitively).

Sorting is performed using Qt's qSort () algorithm, which operates in linear-logarithmic time , i.e. O( n log n ).

If you want to sort your strings in an arbitrary order, consider using the QMap class. For example, you could use a QMap < QString , QString > to create a case-insensitive ordering (e.g. with the keys being lower-case versions of the strings, and the values being the strings), or a QMap <int, QString > to sort the strings by some integer index.

另請參閱 qSort ().

QStringList QStringList:: operator+ (const QStringList & other ) const

Returns a string list that is the concatenation of this string list with the other string list.

另請參閱 append ().

QStringList & QStringList:: operator<< (const QString & str )

Appends the given string, str , to this string list and returns a reference to the string list.

另請參閱 append ().

QStringList & QStringList:: operator<< (const QStringList & other )

這是重載函數。

追加 other string list to the string list and returns a reference to the latter string list.

相關非成員

typedef QMutableStringListIterator

The QStringListIterator type definition provides a Java-style non-const iterator for QStringList .

QStringList provides both Java 風格迭代器 and STL 樣式迭代器 . The Java-style non-const iterator is simply a type definition for QMutableListIterator < QString >.

另請參閱 QStringListIterator and QStringList::iterator .

typedef QStringListIterator

The QStringListIterator type definition provides a Java-style const iterator for QStringList .

QStringList provides both Java 風格迭代器 and STL 樣式迭代器 . The Java-style const iterator is simply a type definition for QListIterator < QString >.

另請參閱 QMutableStringListIterator and QStringList::const_iterator .

QDataStream & operator<< ( QDataStream & out , const QStringList & list )

Writes the given string list 到指定 out stream.

另請參閱 序列化 Qt 數據類型 .

QDataStream & operator>> ( QDataStream & in , QStringList & list )

Reads a string list from the given in stream into the specified list .

另請參閱 序列化 Qt 數據類型 .