problem with interface Class - Error:undefined interface

[k.qasempour]

im trying to test a plugin based application... so as u know i have an interface and then a plug-in which manipulate the interface... i think everything is OK but i face with this error>>
( error: Undefined interface)
. here is my code... how knows wahts the problem


//// pro file
#-------------------------------------------------
#
# Project created by QtCreator 2012-08-11T13:34:07
#
#-------------------------------------------------

QT += core

QT -= gui

TARGET = CAlPlugin_Based
CONFIG += console
CONFIG -= app_bundle



TEMPLATE = app


SOURCES += main.cpp

HEADERS += \
EvaluateInterface.h\
Evaluate.h


//// Evaluate.h file
#ifndef EVALUATE_H
#define EVALUATE_H

#include<EvaluateInterface.h>

class evaluate : public evaluateInterface
{
Q_OBJECT
Q_INTERFACES(evaluateInterface)

public:
QString name1() const;
int evaluate1(int num1, int num2) const;
};

#endif // EVALUATE_H


/
/// EvaluateInterface.h

#ifndef EVALUATEINTERFACE_H
#define EVALUATEINTERFACE_H



class evaluateInterface
{
public:
virtual ~evaluateInterface(){}

virtual QString name1() const=0;
virtual int evaluate1(int num1,int num2) const=0;
};
Q_DECLARE_INTERFACE(evaluateInterface,"CaaaalInterface/1.0")

#endif // EVALUATEINTERFACE_H



Whats the problem then... thank u alll

[high_flyer]

Have class evaluate subclass QObject as well.