My code uses QtCharts.
this has - even in the latest docs - the method axisX()
I use this for
chart->axisX()->setRange(0, data.size());
chart->axisY()->setRange(0, max);
However with Qt 5.12 I get this message
warning: 'QtCharts::QAbstractAxis* QtCharts::QChart::axisY(QtCharts::QAbstractSeries*) const' is deprecated
How am I supposed to replace the code with something not deprecated?
Indeed, the mentioned functions are marked as deprecated in the Qt source code:
Q_DECL_DEPRECATED QAbstractAxis *axisX(QAbstractSeries *series = nullptr) const;
Q_DECL_DEPRECATED QAbstractAxis *axisY(QAbstractSeries *series = nullptr) const;
I think you have to use the following function instead:
QList<QAbstractAxis*> axes(Qt::Orientations orientation = Qt::Horizontal|Qt::Vertical,
QAbstractSeries *series = nullptr) const;
I.e.
auto xAxis = chart->axes(Qt::Horizontal);
auto yAxis = chart->axes(Qt::Vertical);
[..]
Related
Do someone know a solution to do get properties of a QPushButton placed in a QList<QWidget *> ?
.h
QList<QWidget *> list;
.cpp
QPushButton *button = new QPushButton("Push", this);
list->append(button);
qDebug() << list.at(0)->text(); // Not working : text() is not a property of QWidget but a property of QPushButton
Thx
The problem is more to do with c++ and polymorphism in general rather than anything specific to Qt. The expression...
list.at(0)
returns a QWidget *. Hence the call...
list.at(0)->text()
fails to compile as QWidget has no member function named text. If you think the pointer returned by list.at(0) points to a specific subclass of QWidget then you need to downcast it and check the result before using it. e.g.
if (auto *b = dynamic_cast<QPushButton *>(list.at(0)))
qDebug() << b->text();
Alternatively -- since you are using Qt -- you can make use of qobject_cast in a similar fashion...
if (auto *b = qobject_cast<QPushButton *>(list.at(0)))
qDebug() << b->text();
LPCWSTR path;
void WinApiLibrary::StartProcess(QString name)
{
path = name.utf16();
CreateProcess(path, NULL, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi);
}
C:\kursovaya\smc\winapilibrary.cpp:21: error: invalid conversion from
'const ushort* {aka const short unsigned int*}' to 'LPCWSTR {aka const
wchar_t*}' [-fpermissive]
path = name.utf16();
This code worked in the Qt 4.8, but now i have Qt 5.2 and this code isn't working. What's wrong with this guy?
I had the same issue (I'm using Qt 5.3), this is how I fixed it:
QString strVariable1;
LPCWSTR strVariable2 = (const wchar_t*) strVariable1.utf16();
QString::utf16() returns const ushort*, which is different from const wchar_t*, so you have the compile error.
You are probably compiling with /Zc:wchar_t. If you change it to /Zc:wchar_t- it should work, as wchar_t type becomes typedef to 16-bit integer in this case.
In Visual Studio: Project Properties->Configuration Properties->C/C++->Treat WChar_t As Built in Type->No.
Or just add reinterpret_cast<LPCWSTR>.
I'm using Qt 5.2 and I had the same issue. This is how I fixed it:
QString sPath = "C:\\Program File\\MyProg";
wchar_t wcPath[1024];
int iLen = sPath.toWCharArray(wcPath);
In the Qt global namespace, there is the macro qUtf16Printable. However as the documentation states, this produces a temporary so take care to use it properly. Note this was introduced in Qt5.7.
declaration in header file
QColor dialogBoja, dialogBoja1;
.cpp file
dialogBoja = postavke.value("boja", Qt::black).toString();
//postavke means settings
dialogBoja1 = postavke.value("boja1", Qt::white).toString();
As I said on title, when I try to compile this in Qt5 I get error: QVariant::QVariant(Qt::GlobalColor)' is private
How to solve this.
You need to explicitly create a QColor object. This should work:
dialogBoja = postavke.value("boja", QColor(Qt::black)).toString();
The reason for this is explained in the header:
// These constructors don't create QVariants of the type associcated
// with the enum, as expected, but they would create a QVariant of
// type int with the value of the enum value.
// Use QVariant v = QColor(Qt::red) instead of QVariant v = Qt::red for
// example.
Looks like they wanted to divorce QVariant from the QtGui modules, like QColor, and removed that constructor in 5.0. Some syntax is explained here.
Because QVariant is part of the QtCore library, it cannot provide
conversion functions to data types defined in QtGui, such as QColor,
QImage, and QPixmap. In other words, there is no toColor() function.
Instead, you can use the QVariant::value() or the qvariant_cast()
template function.
I'm trying to extract icon from exe file using WinAPI, but it doesn't work.
Here's the code:
QIcon OSTools::AppsInterface::extractAppIcon(const QString &fileName) const {
wchar_t *convertedName = new wchar_t[fileName.length() + 1];
fileName.toWCharArray(convertedName);
convertedName[fileName.length()] = '\0';
HICON Icon = ExtractIcon(NULL, convertedName, 0);
QPixmap pixmap = QPixmap::fromWinHICON(Icon);
return QIcon(pixmap);
}
Code outputs:
QPixmap::fromWinHICON(), failed to GetIconInfo()
(ExtractIcon function on MSDN).
I think problem is that I send NULL instead of "A handle to the instance of the application calling the function". But, generally, I use Qt, and it's only one WinAPI function in my app.
What's wrong? What's correct way to extract icon using WinAPI? If you have another function proposal, please, give me an example. This is the first time I'm using WinAPI.
UPDATE: Yes, there is a better way. You may use QFileIconProvider class for doing such things.
Works for me, even with NULL. But obtaining the HINSTANCE is actually very simple. You have a problem elsewhere i guess. Does your target exe really have an embedded icon?
#ifdef Q_WS_WIN
#include <qt_windows.h>
#endif
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
#ifdef Q_WS_WIN
QString fileName("D:\\_dev\\eclipse\\eclipse.exe");
wchar_t *convertedName = new wchar_t[fileName.length() + 1];
fileName.toWCharArray(convertedName);
convertedName[fileName.length()] = '\0';
HINSTANCE hInstance = ::GetModuleHandle(NULL);
HICON Icon = ::ExtractIcon(hInstance, convertedName, 0);
ui->label->setPixmap(QPixmap::fromWinHICON(Icon));
#endif
}
I used QFileIconProvider, and it worked perfectly. Try this :
QPushButton b;
b.show();
QIcon icon;
QFileIconProvider fileiconpr;
icon = fileIconProvider.icon(QFileInfo("/*file name*/"));
b.setIcon(icon);
// And you can also save it where you want :
QPixmap pixmap = icon.pixmap( QSize(/*desired size*/) );
pixmap.save("/Desktop/notepad-icon.png");
Source. Have a nice day.
And solution was very simple. I just sent path to '.lnk' file instead of path to file. That's my inattention.
I am trying to compile a library written in Qt 4.6. On my current Linux machine I have only Qt 4.7 installed. The following code part:
/*file try.h*/
void fileOpen(QString s = NULL) ;
/*file try.cpp*/
void MainWindow::fileOpen(QString s) {
QString filename ;
if(s.isNull()) filename = QFileDialog::getOpenFileName(
this,
"Choose a file",
".",
"Source file (*.)");
else filename = s ;
}
compiles with the following error (I used cmake but the corresponding line code is the one listed above):
In member function ‘virtual int MainWindow::qt_metacall(QMetaObject::Call, int,
void**)’:
/homes/combi/hodorog/Developments/axelOld/build/axel/src/QGui/moc_MainWindow.cxx:141:26:
error: conversion from ‘long int’ to ‘QString’ is ambiguous
/homes/combi/hodorog/Developments/axelOld/build/axel/src/QGui/moc_MainWindow.cxx:141:26:
note: candidates are:
/usr/include/QtCore/qstring.h:426:43: note: QString::QString(const char*)
/usr/include/QtCore/qstring.h:105:14: note: QString::QString(const QChar*)
So I am guessing the problem is that in qt. 4.7. there are two QString constructors that can take a pointer as an argument (as listed in the compilation error), whereas in qt 4.6. there is only one QString constructor that can take a pointer as an argument. How can I force QString to call the constructor with const char * as an argument?
Thank a lot for your help in advance,
madalina
void fileOpen(QString s = NULL);
You are trying to construct a QString object with 0. It seems you are confusing the null of pointers with a null QString. A null QString is one which is created with the constructor QString(). Given how your function is implemented (referring to s.isNull()), you should change the function declaration to
void fileOpen(QString s = QString());