From Forum Nokia Wiki

ID		Creation date	29 December 2008
Platform	S60 3rd Edition, S60 5th Edition	Tested on devices	Emulator
Category	Qt for Symbian	Subcategory

Keywords (APIs, classes, methods, functions): Q_OBJECT

Introduction

The Q_OBJECT macro at the beginning of the class definition is necessary for all classes that define signals, slots or uses a service provided by the meta-object system.

The QObject class is the base class for the object that uses the meta-object system (like signals and slots). Q_OBJECT enables the meta-object feature and it must be written without ';' at the end of line.

Forgetting Q_OBJECT is a common error among beginners. The class will not compile, and the compiler shows some errors about some methods missing in the table.

Preconditions

• Download and Install latest version Qt for Symbian - Installation packages which has links on how to install the latest version.
• The header file must included in the headers section of the .pro file otherwise linker errors will be result.

Code Snippet

#include <QObject>
class Counter: public QObject
{
    Q_OBJECT
//some code here
};