Porting from QT4.6 to QT5

mrjj · 6 Feb 2018, 10:43

Hi
They changed the includes so make sure you include the right ones.
Also they renamed UnicodeUTF8. But hard to guess at without code context where error comes.
if using old project, make sure to delete ANY left over ui_xxx files

https://wiki.qt.io/Transition_from_Qt_4.x_to_Qt5

Its most likely inside the ui_ files you get it.

Christian Ehrlicher · wrote on 2 Jun 2018, 11:06

And make sure to not include the qt4 headers by accident - this can happen easily and create a lot of strange compiler errors...

Qt Enthusiast · wrote on 14 Jun 2018, 21:08

Hi All
https://forum.qt.io/topic/91657/compilation-errors-when-porting-from-qt4-to-qt5/2

Can someone guide me how to install plugin for QMotifyStyle

SGaist · 14 Jun 2018, 21:43

As this 6 year old blog post explains, these styles have moved to the QtStylePlugins module.

Qt Enthusiast · 15 Jun 2018, 04:25

@SGaist
how to install the plugin it is still not clear to me if you can directly suggest the code changes

jsulm · wrote on 15 Jun 2018, 04:25

@Qt-Enthusiast With a short search you can find: https://forum.qt.io/topic/65912/how-to-install-qtstyleplugins/7

Qt Enthusiast · wrote on 17 Jun 2018, 04:07

ui_widget.h:177:119: error: 'UnicodeUTF8' is not a member of 'QApplication'
6987 browser->xt(QApplication::translate("exportWidget", "View in browser after exporting", 0, QApplication::UnicodeUTF8));

how to solve this issue and ui_widget.h is generated by uic

Qt Enthusiast · wrote on 17 Jun 2018, 04:48

I am getting a lot of issues when ui files

Christian Ehrlicher · wrote on 17 Jun 2018, 06:11

You're using the wrong uic (the one from Qt4) as it seems. Make sure to recreate your Makefiles with qmake for Qt5!

SGaist · wrote on 17 Jun 2018, 20:08

One more thing, ensure that your source tree doesn't contain any generated file e.g. ui_*.h, etc. only original sources, .qrc, .ui file etc.

Qt Enthusiast · 20 Jun 2018, 14:59

I am getting following error

how to solve this error

QString myString
error: 'class QString' has no member named 'toAscii'
execute(myString.toAscii();

mrjj · wrote on 20 Jun 2018, 14:59

@Qt-Enthusiast
Its in the docs. i linked before.
https://wiki.qt.io/Transition_from_Qt_4.x_to_Qt5#toAscii.28.29_and_fromAscii.28.29_Methods_are_deprecated

Qt Enthusiast · 20 Jun 2018, 15:41

One more question, I am getting following errors

void myClass::mythod() {
bool x = FALSE;
booly = TRUE;
}

error: 'FALSE' was not declared in this scope

any reason why and how to solve this issue

is there FALSE is declared in qt4 source code

mrjj · 21 Jun 2018, 05:44

@Qt-Enthusiast
just use the c++ versions
true
false
(in small letters)

Qt Enthusiast · wrote on 21 Jun 2018, 03:44

what is significance of FALSE and TRUE in Qt4

Qt Enthusiast · 21 Jun 2018, 04:42

Also I am getting an error
mainwindow.h:17:0: error: "Q_NULLPTR" redefined [-Werror]

is Q_NULLPTR defined in SRC of QT5

jsulm · wrote on 21 Jun 2018, 04:42

@Qt-Enthusiast Please post your code (mainwindow.h).
Also it is better to use nullptr from C++11 now.

Qt Enthusiast · 21 Jun 2018, 05:55

@mrjj
is FALSE and TRUE defined in qt4 code

JKSH · wrote on 21 Jun 2018, 05:55

@Qt-Enthusiast said in Porting from QT4.6 to QT5:

is FALSE and TRUE defined in qt4 code

No.

Qt Enthusiast · 21 Jun 2018, 05:57

Then why I am getting this error when I am changing the library to Qt5