How do I use my own subclass in the ui?



  • I have extended the QDoubleSpinBox to my own subclass MySpinBox, then I created a doublespinbox object in the ui designer and promoted it to use MySpinBox class. But when I ran it, it gave me this long error:

    mainwindow.obj:-1: error: LNK2019: unresolved external symbol "public: __cdecl MySpinBox::MySpinBox(class QWidget *)" (??0MySpinBox@@QEAA@PEAVQWidget@@@Z) referenced in function "public: void __cdecl Ui_MainWindow::setupUi(class QMainWindow *)" (?setupUi@Ui_MainWindow@@QEAAXPEAVQMainWindow@@@Z)
    

    This is my files.

    my_spinbox.h

    #ifndef MY_SPINBOX_H
    #define MY_SPINBOX_H
    
    #include <QDoubleSpinBox>
    
    class MySpinBox: public QDoubleSpinBox
    {
        Q_OBJECT
    
    public:
        MySpinBox(QWidget *parent = nullptr);
    
    };
    
    #endif // MY_SPINBOX_H
    

    my_spinbox.cpp

    #include "my_spinbox.h"
    
    MySpinBox::MySpinBox(QWidget *parent): QDoubleSpinBox(parent)
    {
    }
    

    What is wrong?



  • Hi, in your .pro file, check if you have

    HEADERS += my_spinbox.h
    SOURCES += my_spinbox.cpp
    

  • Qt Champions 2017

    Hi
    Also sometimes it can be a bit happy to cache files
    so if you have headers as @hskoglund says then
    go and delete your build folder and run qmake and rebuild all.



  • @mrjj Thank you, that's the problem. I deleted the build folder and rebuild it again and it works.


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.