Porting from QT4.6 to QT5

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.

Qt Enthusiast

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

jsulm

@Qt-Enthusiast Do you use same compiler for both Qt versions?

JKSH

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

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

Because you also changed your compiler?

Qt Enthusiast

@jsulm

Yes
I changed just the qt version. What is significance of Q_NULLPTR

jsulm

@Qt-Enthusiast Well, if you search a bit you will find this in Qt source:

#ifdef Q_COMPILER_NULLPTR
# define Q_NULLPTR         nullptr
#else
# define Q_NULLPTR         NULL
#endif

If you have a C++11 compiler Q_NULLPTR will be nullptr, else it will be the old C/C++ NULL.
You can use Q_NULLPTR if you have to support older C++ compilers which do not know anything about nullptr and newer C++ compilers.

Qt Enthusiast

how to solve the following error

error: no matching function for call to 'QGraphicsTextItem::QGraphicsTextItem(const char [5], int, QGraphicsScene*&)'
cursor = new QGraphicsTextItem("0, 0", 0, scene);

jsulm

@Qt-Enthusiast Go here and check what constructors QGraphicsTextItem has: http://doc.qt.io/qt-5/qgraphicstextitem.html

Qt Enthusiast

Hi
I saw
http://doc.qt.io/qt-5/qgraphicsscene.html

QGraphicsItem * itemAt(const QPointF &position, const QTransform &deviceTransform) const
QGraphicsItem * itemAt(qreal x, qreal y, const QTransform &deviceTransform) const

buit still could not find the correct fix for compliation error

What const QTransform &deviceTransform shall I use

error: no matching function for call to 'QGraphicsScene::itemAt(QPointF&)'
QPointF m ;
QGraphicsItem *currentItem = scene->itemAt(m);

jsulm

@Qt-Enthusiast http://doc.qt.io/qt-5/qgraphicsscene.html#itemAt has two parameters not one.
Try to pass QTransform() as second parameter.

Qt Enthusiast

I am getting issue

I am getting errors like

file.cxx: In member function 'bool fileMgr::showURL(QString)':
error: 'QWebView' does not name a type
340 static QWebView *sBrowser = NULL;
341 ^

I tried to do
#include QtWebKitWidgets
#include QtWebView

It is giving me an error that not able to find file QtWebKitWidgets .

can some one help me in solving the problem

JKSH

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

It is giving me an error that not able to find file QtWebKitWidgets .

can some one help me in solving the problem

See https://forum.qt.io/topic/76739/webkit-status-2017