Porting from QT4.6 to QT5

[Qt Enthusiast]

I am porting my GUI from Qt4.6 to Qt5.7.0 and I am getting multiple compilation issues
error: 'UnicodeUTF8' is not a member of 'QApplication'
QFormLayout' is not a class, namespace, or enumeration

and many such , could you please in the same

[mrjj]

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]

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]

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]

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

[Qt Enthusiast]

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

[jsulm]

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

[Qt Enthusiast]

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]

I am getting a lot of issues when ui files

[Christian Ehrlicher]

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

[SGaist]

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]

I am getting following error

how to solve this error

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

[mrjj]

@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]

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]

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

[Qt Enthusiast]

what is significance of FALSE and TRUE in Qt4

[Qt Enthusiast]

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

is Q_NULLPTR defined in SRC of QT5

[jsulm]

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

[Qt Enthusiast]

@mrjj
is FALSE and TRUE defined in qt4 code

[JKSH]

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

is FALSE and TRUE defined in qt4 code

No.