QRegularExpressionValidator 类

QRegularExpressionValidator 类用于根据正则表达式校验字符串。更多...

头：	#include <QRegularExpressionValidator>
qmake:	QT += gui
Since:	Qt 5.1
继承：	QValidator

该类在 Qt 5.1 引入。

所有成员列表，包括继承成员

特性

regularExpression : QRegularExpression

公共函数

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

重实现公共函数

virtual QValidator::State

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

公共槽

void	setRegularExpression (const QRegularExpression & re )

信号

void	regularExpressionChanged (const QRegularExpression & re )

详细描述

QRegularExpressionValidator 使用 regexp (正则表达式) 确定输入字符串是否 Acceptable , 中间体，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 中间体 . For example, "" and "A" are 中间体 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.

用法范例：

// 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);

下文呈现一些验证器范例。在实践中，它们通常关联上文范例中的 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

另请参阅 QRegularExpression , QIntValidator , QDoubleValidator ，和 QRegExpValidator .

特性文档编制

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).

访问函数：

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

通知程序信号：

void	regularExpressionChanged (const QRegularExpression & re )

成员函数文档编制

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

构造验证器采用 parent object that accepts all strings that match the regular expression re .

QRegularExpressionValidator:: QRegularExpressionValidator ( QObject * parent = nullptr)

构造验证器采用 parent object that accepts any string (including an empty one) as valid.

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

销毁验证器。

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

重实现： QValidator::validate (QString &input, int &pos) const.

返回 Acceptable if input is matched by the regular expression for this validator, 中间体 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 中间体 , and "+9" is Invalid .

另请参阅 QRegularExpression::match ().