子类化 QFileDialog

Question

I'd like to subclass QFileDialog to add a few parameters to it. Basically, I'd like to add a few widgets that would specify how exactly the file should be saved. What do I need to do for that?

class ExportDialog : public QFileDialog
{
    Q_OBJECT

    public:
        ExportDialog( QWidget *parent ) : QFileDialog( parent )
        {
            setAcceptMode( QFileDialog::AcceptSave );
        }

        void AddParameterWidgets()
        {
            ...

I am getting errors like these:

menu_file.cpp:756: undefined reference to `vtable for ExportDialog'

Answer 1

undefined reference to 'vtable for ExportDialog' can be caused by missing virtual functions.

Often with Qt, it happens when you add a new file with a Q_OBJECT . If this is the case it can be solved by forcing qmake to re-run: "Right-click on your project > Run qmake" or using the menu "Build > Run qmake".

The root cause is that when you added the file the Q_OBJECT macro was not detected and therefore the file is not processed by the moc. Running qmake will detect the Q_OBJECT macro.

If this does not solve your issue, look into your code for functions declared in your class but not defined anywhere.

If this still does not work, they you need to complete your question by providing a minimal reproducible example.