QRegularExpressionValidator Class
The QRegularExpressionValidator class is used to check a string against a regular expression. 更多...
头文件: | #include <QRegularExpressionValidator> |
qmake: | QT += gui |
开始支持版本: | Qt 5.1 |
基类: | QValidator |
属性
- regularExpression : QRegularExpression
- 1 个属性继承自 QObject
公有函数
QRegularExpressionValidator(QObject *parent = Q_NULLPTR) | |
QRegularExpressionValidator(const QRegularExpression &re, QObject *parent = Q_NULLPTR) | |
~QRegularExpressionValidator() | |
QRegularExpression | regularExpression() const |
重新实现的公有函数
virtual QValidator::State | validate(QString &input, int &pos) const |
- 4 个公有函数继承自 QValidator
- 32 个公有函数继承自 QObject
公有槽函数
void | setRegularExpression(const QRegularExpression &re) |
- 1 个公有槽函数继承自 QObject
信号
void | regularExpressionChanged(const QRegularExpression &re) |
- 1 个信号继承自 QValidator
- 2 个信号继承自 QObject
其他继承的成员
详细描述
The QRegularExpressionValidator class is used to check a string against a regular expression.
QRegularExpressionValidator uses a regular expression (regexp) to determine whether an input string is Acceptable, Intermediate, or 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 Intermediate. For example, "" and "A" are Intermediate 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.
Example of use:
// 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);
Below we present some examples of validators. In practice they would normally be associated with a widget as in the example above.
// 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
参见 QRegularExpression, QIntValidator, QDoubleValidator, and QRegExpValidator.
属性
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) |
Notifier signal:
void | regularExpressionChanged(const QRegularExpression &re) |
成员函数
QRegularExpressionValidator::QRegularExpressionValidator(QObject *parent = Q_NULLPTR)
Constructs a validator with a parent object that accepts any string (including an empty one) as valid.
QRegularExpressionValidator::QRegularExpressionValidator(const QRegularExpression &re, QObject *parent = Q_NULLPTR)
Constructs a validator with a parent object that accepts all strings that match the regular expression re.
QRegularExpressionValidator::~QRegularExpressionValidator()
Destroys the validator.
[virtual]
QValidator::State QRegularExpressionValidator::validate(QString &input, int &pos) const
Reimplemented from QValidator::validate().
Returns Acceptable if input is matched by the regular expression for this validator, Intermediate 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 Intermediate, and "+9" is Invalid.