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

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

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)

其他继承的成员

  • 1 个公有变量继承自 QObject
  • 10 个静态公有成员继承自 QObject
  • 9 个受保护的函数继承自 QObject
  • 2 个受保护的变量继承自 QObject

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.

参见 QRegularExpression::match().