Trying to construct an instance of an invalid type, type id: 145

smita30apr

Hi,

I am getting these messages as warnings in my Desktop Application using Qt 5:

Trying to construct an instance of an invalid type, type id: 145
Trying to construct an instance of an invalid type, type id: 145
Trying to construct an instance of an invalid type, type id: 145
Trying to construct an instance of an invalid type, type id: 145

The gui runs fine. Its just that I get these warnings. What could be wrong?

Thanks :)

leon.anavi

Could you please provide the source code which generates this warning? I guess that you might be using QVariant in an appropriate way.

smita30apr

Thank you for your reply!

QVariant is being used in many places in the code actually. So What do you mean by using QVariant unappropriately? I can search for all existing QVariants, but how to see if its used correctly. Do you have any idea about the significance of "145" id, that its generating.

SGaist

Hi,

Did you:

declared your type with Q_DECLARE_METATYPE ?
call qRegisterMetaTypeStreamOperators and implement both stream operators ?

smita30apr

Yes I have. Declared my new type with Q_DECLARE_METATYPE and used qRegisterMetaTypeStreamOperators

smita30apr

I tried to debug, seems its happening with a QTreeView. My code is below

@
QAction *show_user_action = QAction("User");
show_user_action->setCheckable(true);
show_user_action->setChecked(show_user); connect(show_user_action,SIGNAL(triggered(bool)),
m_directory_view,SLOT(show_column(bool)));
@

On Calling:
show_user_action->trigger();
those warnings are displayed.

the slot code is:

@
show_column(bool show) {

QAction *action = qobject_cast< QAction *>(QObject::sender());
QString action_name = action->get_name();
m_filter_model->set_column_visible(action_name,show);
m_directory_view->header()->resizeSections(QHeaderView::ResizeToContents);
}
@

The last line m_directory_view->header()->resizeSections(QHeaderView::ResizeToContents); generates the warning.

Any clue here?

[edit: added missing coding tags @ SGaist]

SGaist

Well… It looks unrelated.

Do you have any QVariant stuff in your code ? QSettings ?

smita30apr

Well, I added a breakpoint at m_directory_view->header()->resizeSections(QHeaderView::ResizeToContents);
and once it is executed it generates that warning. Its strange though.
But I use both QVariant and QSettings. Actually line 3 at the above code:
show_user_action->setChecked(show_user); <- show_user is a QVariant stored in QSettings.

What can I check for here?

SGaist

Are you storing one of your custom class in QSettings ?