Our experience with Designer started in Qt3. Qt3 At that point, Designer was useful mainly to generate code that you would then compile into your application. We started using for that purpose but with all generated code, once you edit it, you can no longer go back and regenerate it without losing your edits. We … Read more
Well, the Qt FAQ says: int main(int argc, char **argv) { QApplication app(argc, argv); QString str1 = “Test”; QByteArray ba = str1.toLocal8Bit(); const char *c_str2 = ba.data(); printf(“str2: %s”, c_str2); return app.exec(); } So perhaps you’re having other problems. How exactly doesn’t this work?
Use ldd (man ldd) to show shared library dependencies. Running this on libqxcb.so …/platforms$ ldd libqxcb.so shows that xcb depends on libQt5DBus.so.5 in addition to libQt5Core.so.5 and libQt5Gui.so.5 (and many other system libs). Add libQt5DBus.so.5 to your collection of shared libs and you should be ready to move on.
You should install package “libgl1-mesa-dev”: sudo apt install libgl1-mesa-dev
The proper way to do this is like this: LIBS += -L/path/to -lpsapi This way it will work on all platforms supported by Qt. The idea is that you have to separate the directory from the library name (without the extension and without any ‘lib’ prefix). Of course, if you are including a Windows specific … Read more
>= Xcode 8 In Xcode 8, as Bruce said, this happens when Qt tries to find xcrun when it should be looking for xcodebuild. Open the file: Qt_install_folder/5.7/clang_64/mkspecs/features/mac/default_pre.prf Replace: isEmpty($$list($$system(“/usr/bin/xcrun -find xcrun 2>/dev/null”))) With: isEmpty($$list($$system(“/usr/bin/xcrun -find xcodebuild 2>/dev/null”))) ~> Xcode 8 Before Xcode 8, this problem occurs when command line tools are installed after Xcode … Read more
The implementation of a non-specialized template must be visible to a translation unit that uses it. The compiler must be able to see the implementation in order to generate code for all specializations in your code. This can be achieved in two ways: 1) Move the implementation inside the header. 2) If you want to … Read more
You would use QMessageBox::question for that. Example in a hypothetical widget’s slot: #include <QApplication> #include <QMessageBox> #include <QDebug> // … void MyWidget::someSlot() { QMessageBox::StandardButton reply; reply = QMessageBox::question(this, “Test”, “Quit?”, QMessageBox::Yes|QMessageBox::No); if (reply == QMessageBox::Yes) { qDebug() << “Yes was clicked”; QApplication::quit(); } else { qDebug() << “Yes was *not* clicked”; } } Should work … Read more
Use isatty: #include <stdio.h> #include <io.h> … if (isatty(fileno(stdin))) printf( “stdin is a terminal\n” ); else printf( “stdin is a file or a pipe\n”); (On windows they’re prefixed with underscores: _isatty, _fileno)
First of all, it’s very important to understand that for using Qt with Visual Studio 2010, it’s not possible to use the pre-built binaries which were made for Visual Studio 2008, but you have to compile it from source. Downloading Qt On https://www.qt.io/download/ Update 2017: the latest Qt 4.x branch (Qt 4.8.6) has 2 pre-built … Read more