QRegularExpressionValidator 類

QRegularExpressionValidator 類用於根據正則錶達式校驗字符串。更多...

頭：	#include <QRegularExpressionValidator>
qmake:	QT += gui
Since:	Qt 5.1
繼承：	QValidator

該類在 Qt 5.1 引入。

所有成員列錶，包括繼承成員

特性

regularExpression : QRegularExpression

公共函數

	QRegularExpressionValidator (const QRegularExpression & re , QObject * parent = nullptr)
	QRegularExpressionValidator (QObject * parent = nullptr)
virtual	~QRegularExpressionValidator ()
QRegularExpression	regularExpression () const

重實現公共函數

virtual QValidator::State

validate (QString & input , int & pos ) const override

公共槽

void	setRegularExpression (const QRegularExpression & re )

信號

void	regularExpressionChanged (const QRegularExpression & re )

詳細描述

QRegularExpressionValidator 使用 regexp (正則錶達式) 確定輸入字符串是否 Acceptable , 中間體，或 Invalid . The regexp can either be supplied when the QRegularExpressionValidator is constructed, or at a later time.

If the regexp partially matches against the string, the result is considered 中間體 . For example, "" and "A" are 中間體 for the regexp [A-Z][0-9] (whereas " _ " would be Invalid ).

QRegularExpressionValidator automatically wraps the regular expression in the \\A and \\z anchors; in other words, it always attempts to do an exact match.

用法範例：

// regexp: optional '-' followed by between 1 and 3 digits
QRegularExpression rx("-?\\d{1,3}");
QValidator *validator = new QRegularExpressionValidator(rx, this);
QLineEdit *edit = new QLineEdit(this);
edit->setValidator(validator);

下文呈現一些驗證器範例。在實踐中，它們通常關聯上文範例中的 Widget。

// integers 1 to 9999
QRegularExpression re("[1-9]\\d{0,3}");
// the validator treats the regexp as "^[1-9]\\d{0,3}$"
QRegularExpressionValidator v(re, 0);
QString s;
int pos = 0;
s = "0";     v.validate(s, pos);    // returns Invalid
s = "12345"; v.validate(s, pos);    // returns Invalid
s = "1";     v.validate(s, pos);    // returns Acceptable
re.setPattern("\\S+");            // one or more non-whitespace characters
v.setRegularExpression(re);
s = "myfile.txt";  v.validate(s, pos); // Returns Acceptable
s = "my file.txt"; v.validate(s, pos); // Returns Invalid
// A, B or C followed by exactly five digits followed by W, X, Y or Z
re.setPattern("[A-C]\\d{5}[W-Z]");
v.setRegularExpression(re);
s = "a12345Z"; v.validate(s, pos);        // Returns Invalid
s = "A12345Z"; v.validate(s, pos);        // Returns Acceptable
s = "B12";     v.validate(s, pos);        // Returns Intermediate
// match most 'readme' files
re.setPattern("read\\S?me(\.(txt|asc|1st))?");
re.setPatternOptions(QRegularExpression::CaseInsensitiveOption);
v.setRegularExpression(re);
s = "readme";      v.validate(s, pos); // Returns Acceptable
s = "README.1ST";  v.validate(s, pos); // Returns Acceptable
s = "read me.txt"; v.validate(s, pos); // Returns Invalid
s = "readm";       v.validate(s, pos); // Returns Intermediate

另請參閱 QRegularExpression , QIntValidator , QDoubleValidator ，和 QRegExpValidator .

特性文檔編製

regularExpression : QRegularExpression

This property holds the regular expression used for validation

By default, this property contains a regular expression with an empty pattern (which therefore matches any string).

訪問函數：

QRegularExpression	regularExpression () const
void	setRegularExpression (const QRegularExpression & re )

通知程序信號：

void	regularExpressionChanged (const QRegularExpression & re )

成員函數文檔編製

QRegularExpressionValidator:: QRegularExpressionValidator (const QRegularExpression & re , QObject * parent = nullptr)

構造驗證器采用 parent object that accepts all strings that match the regular expression re .

QRegularExpressionValidator:: QRegularExpressionValidator ( QObject * parent = nullptr)

構造驗證器采用 parent object that accepts any string (including an empty one) as valid.

`[虛擬]` QRegularExpressionValidator:: ~QRegularExpressionValidator ()

銷毀驗證器。

`[override virtual]` QValidator::State QRegularExpressionValidator:: validate ( QString & input , int & pos ) const

重實現： QValidator::validate (QString &input, int &pos) const.

返迴 Acceptable if input is matched by the regular expression for this validator, 中間體 if it has matched partially (i.e. could be a valid match if additional valid characters are added), and Invalid if input is not matched.

In case the input is not matched, the pos parameter is set to the length of the input parameter; otherwise, it is not modified.

For example, if the regular expression is \w\d\d (word-character, digit, digit) then "A57" is Acceptable , "E5" is 中間體 , and "+9" is Invalid .

另請參閱 QRegularExpression::match ().