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QCoreApplication Class Reference
[com.trolltech.qt.core module]

The QCoreApplication class provides an event loop for console Qt applications. More...

Inherits QObject.

Inherited by QApplication.


Detailed Description

The QCoreApplication class provides an event loop for console Qt applications.

This class is used by non-GUI applications to provide their event loop. For non-GUI application that uses Qt, there should be exactly one QCoreApplication object. For GUI applications, see QApplication.

QCoreApplication contains the main event loop, where all events from the operating system (e.g., timer and network events) and other sources are processed and dispatched. It also handles the application's initialization and finalization, as well as system-wide and application-wide settings.

The command line arguments which QCoreApplication's constructor should be called with are accessible using arguments. The event loop is started with a call to exec. Long running operations can call processEvents to keep the application responsive.

Some Qt classes, such as QString, can be used without a QCoreApplication object. However, in general, we recommend that you create a QCoreApplication or a QApplication object in your main() function as early as possible. The application will enter the event loop when exec is called. exit will not return until the event loop exits, e.g., when quit is called.

An application has an applicationDirPath and an applicationFilePath. Translation files can be added or removed using installTranslator and removeTranslator. Application strings can be translated using translate(). The QObject::tr() and QObject::trUtf8() functions are implemented in terms of translate().

The class provides a quit slot and an aboutToQuit signal.

Several static convenience functions are also provided. The QCoreApplication object is available from instance. Events can be sent or posted using sendEvent, postEvent, and sendPostedEvents. Pending events can be removed with removePostedEvents or flushed with flush. Library paths (see QLibrary) can be retrieved with libraryPaths and manipulated by setLibraryPaths, addLibraryPath, and removeLibraryPath.

See also QApplication, QAbstractEventDispatcher, QEventLoop, Semaphores Example, and Wait Conditions Example.


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Qt Jambi 4.3.5_01