The QMessageLogger class generates log messages. More...
Header: | #include <QMessageLogger> |
qmake: | QT += core |
Since: | Qt 5.0 |
typedef | CategoryFunction |
QMessageLogger() | |
QMessageLogger(const char *file, int line, const char *function) | |
QMessageLogger(const char *file, int line, const char *function, const char *category) | |
void | critical(const char *msg, ...) const |
void | critical(const QLoggingCategory &cat, const char *msg, ...) const |
void | critical(QMessageLogger::CategoryFunction catFunc, const char *msg, ...) const |
QDebug | critical() const |
QDebug | critical(const QLoggingCategory &cat) const |
QDebug | critical(QMessageLogger::CategoryFunction catFunc) const |
void | debug(const char *msg, ...) const |
void | debug(const QLoggingCategory &cat, const char *msg, ...) const |
void | debug(QMessageLogger::CategoryFunction catFunc, const char *msg, ...) const |
QDebug | debug() const |
QDebug | debug(const QLoggingCategory &cat) const |
QDebug | debug(QMessageLogger::CategoryFunction catFunc) const |
void | fatal(const char *msg, ...) const |
void | info(const char *msg, ...) const |
void | info(const QLoggingCategory &cat, const char *msg, ...) const |
void | info(QMessageLogger::CategoryFunction catFunc, const char *msg, ...) const |
QDebug | info() const |
QDebug | info(const QLoggingCategory &cat) const |
QDebug | info(QMessageLogger::CategoryFunction catFunc) const |
void | warning(const char *msg, ...) const |
void | warning(const QLoggingCategory &cat, const char *msg, ...) const |
void | warning(QMessageLogger::CategoryFunction catFunc, const char *msg, ...) const |
QDebug | warning() const |
QDebug | warning(const QLoggingCategory &cat) const |
QDebug | warning(QMessageLogger::CategoryFunction catFunc) const |
The QMessageLogger class generates log messages.
QMessageLogger is used to generate messages for the Qt logging framework. Usually one uses it through qDebug(), qInfo(), qWarning(), qCritical, or qFatal() functions, which are actually macros: For example qDebug() expands to QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).debug() for debug builds, and QMessageLogger(0, 0, 0).debug() for release builds.
One example of direct use is to forward errors that stem from a scripting language, e.g. QML:
void statusChanged(QDeclarativeComponent::Status status) { if (status == QDeclarativeComponent::Error) { foreach (const QDeclarativeError &error, component->errors()) { const QByteArray file = error.url().toEncoded(); QMessageLogger(file.constData(), error.line(), 0).debug() << error.description(); } } }
See also QMessageLogContext, qDebug(), qInfo(), qWarning(), qCritical(), and qFatal().
This is a typedef for a pointer to a function with the following signature:
const QLoggingCategory &category();
A function which this signature is generated by Q_DECLARE_LOGGING_CATEGORY, Q_LOGGING_CATEGORY.
This typedef was introduced in Qt 5.3.
Constructs a default QMessageLogger. See the other constructors to specify context information.
Constructs a QMessageLogger to record log messages for file at line in function. The is equivalent to QMessageLogger(file, line, function, "default")
Constructs a QMessageLogger to record category messages for file at line in function.
Logs a critical message specified with format msg. Additional parameters, specified by msg, may be used.
See also qCritical().
Logs a critical message specified with format msg for the context cat. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.3.
See also qCCritical().
Logs a critical message specified with format msg for the context returned by catFunc. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.3.
See also qCCritical().
Logs a critical message using a QDebug stream
See also qCritical() and QDebug.
Logs a critical message into category cat using a QDebug stream.
This function was introduced in Qt 5.3.
See also qCCritical() and QDebug.
Logs a critical message into category returned by catFunc using a QDebug stream.
This function was introduced in Qt 5.3.
See also qCCritical() and QDebug.
Logs a debug message specified with format msg. Additional parameters, specified by msg, may be used.
See also qDebug().
Logs a debug message specified with format msg for the context cat. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.3.
See also qCDebug().
Logs a debug message specified with format msg for the context returned by catFunc. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.3.
See also qCDebug().
Logs a debug message using a QDebug stream
Logs a debug message into category cat using a QDebug stream.
This function was introduced in Qt 5.3.
See also qCDebug() and QDebug.
Logs a debug message into category returned by catFunc using a QDebug stream.
This function was introduced in Qt 5.3.
See also qCDebug() and QDebug.
Logs a fatal message specified with format msg. Additional parameters, specified by msg, may be used.
See also qFatal().
Logs an informational message specified with format msg. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.5.
See also qInfo().
Logs an informational message specified with format msg for the context cat. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.5.
See also qCInfo().
Logs an informational message specified with format msg for the context returned by catFunc. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.5.
See also qCInfo().
Logs an informational message using a QDebug stream.
This function was introduced in Qt 5.5.
Logs an informational message into the category cat using a QDebug stream.
This function was introduced in Qt 5.5.
Logs an informational message into category returned by catFunc using a QDebug stream.
This function was introduced in Qt 5.5.
Logs a warning message specified with format msg. Additional parameters, specified by msg, may be used.
See also qWarning().
Logs a warning message specified with format msg for the context cat. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.3.
See also qCWarning().
Logs a warning message specified with format msg for the context returned by catFunc. Additional parameters, specified by msg, may be used.
This function was introduced in Qt 5.3.
See also qCWarning().
Logs a warning message using a QDebug stream
See also qWarning() and QDebug.
Logs a warning message into category cat using a QDebug stream.
See also qCWarning() and QDebug.
Logs a warning message into category returned by catFunc using a QDebug stream.
This function was introduced in Qt 5.3.