unresolved external symbol Q_OBJECT and #define

unresolved external symbol "public: virtual struct QMetaObject const * __cdecl Widget::metaObject(void)const " (?metaObject@Widget@@UEBAPEBUQMetaObject@@XZ)

unresolved external symbol "public: virtual void * __cdecl Widget::qt_metacast(char const *)" (?qt_metacast@Widget@@UEAAPEAXPEBD@Z)

unresolved external symbol "public: virtual int __cdecl Widget::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@Widget@@UEAAHW4Call@QMetaObject@@HPEAPEAX@Z)

3 unresolved externals

//test.h
#pragma once  

#if CUSTOM_WIDGET

class Widget : public QWidget
{
   Q_OBJECT
public:	
   Widget(QWidget* parent = nullptr);
};

#endif 

// stdafx.h
#include <QtWidgets>
#define CUSTOM_WIDGET 1