Unresolved external symbol LNK2019 Qt Creator

Question

I have probably seen all the topics discussing this issue but I still can't fix it

#pragma once

#include <QObject>
#include <QApplication>
#include <QObject>
#include <QWidget>
#include <QPushButton>
#include <QLineEdit>
#include <QHBoxLayout>

class input : public QObject {

    Q_OBJECT

public:
    input();

public slots:
  void text();


signals:
    void buttonclicked();


private:
    QWidget * w = new QWidget;
    QPushButton * ok = new QPushButton;
    QLineEdit * line = new QLineEdit;
    QHBoxLayout * layout = new QHBoxLayout;
};

this is a really simple header without implementation yet but when I build it to check the code it gives me this error and I can't really solve it

moc_clss.obj:-1: error: LNK2019: unresolved external symbol "public: void __cdecl input::text(void)" (?text@input@@QEAAXXZ) referenced in function "private: static void __cdecl input::qt_static_metacall(class QObject *,enum QMetaObject::Call,int,void * *)" (?qt_static_metacall@input@@CAXPEAVQObject@@W4Call@QMetaObject@@HPEAPEAX@Z)

so help please if you can .

*"this is a really simple header without implementation yet"* - Correct. That's what the linker is telling you as well. So please, do provide an implementation (or remove the `Q_OBJECT` so that the MOC compiler won't reference it). — IInspectable, Mar 06 '17 at 20:37
yes but when i implemented it i got the same error so i removed the implementation to see what is the problem and it is still the same — Hazem Gamal, Mar 06 '17 at 20:45
If you had it implemented then you have to check why the source file that implemented it was not being compiled and linked into your executable. Maybe you forgot to save the source file before you built. — drescherjm, Mar 06 '17 at 20:48
and yes I removed the Q_OBJECT as you said but it still gives me the exact same error — Hazem Gamal, Mar 06 '17 at 20:50
That is supposed to be the constructor. `input();` is correct. `void input();` is not correct. — drescherjm, Mar 06 '17 at 20:58
yes it is already correct because this is the default constructor, not a function — Hazem Gamal, Mar 06 '17 at 21:12
"when i implemented it i got the same error" That's because you haven't built your implementation. You must prove it to yourself that the implementation is being built. Delete the project's build folder and build it again. — Kuba hasn't forgotten Monica, Mar 07 '17 at 13:39

Unresolved external symbol LNK2019 Qt Creator

0 Answers0