The QRegularExpressionValidator class is used to check a string against a regular expression. 更多...
| 頭: | #include <QRegularExpressionValidator> |
| qmake: | QT += gui |
| Since: | Qt 5.1 |
| 繼承: | QValidator |
| QRegularExpressionValidator (QObject * parent = Q_NULLPTR) | |
| QRegularExpressionValidator (const QRegularExpression & re , QObject * parent = Q_NULLPTR) | |
| ~QRegularExpressionValidator () | |
| QRegularExpression | regularExpression () const |
| virtual QValidator::State | validate (QString & input , int & pos ) const |
| void | setRegularExpression (const QRegularExpression & re ) |
| void | regularExpressionChanged (const QRegularExpression & re ) |
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 , 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 .
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 ) |
構造驗證器采用 parent object that accepts any string (including an empty one) as valid.
構造驗證器采用 parent object that accepts all strings that match the regular expression re .
銷毀驗證器。
[虛擬]
QValidator::State
QRegularExpressionValidator::
validate
(
QString
&
input
,
int
&
pos
) const
重實現自 QValidator::validate ().
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 ().