wget https://download.qt.io/official_releases/qtcreator/3.5/3.5.1/qt-creator-opensource-linux-x86_64-3.5.1.run chmod +x qt-creator-opensource-linux-x86_64-3.5.1.run ./qt-creator-opensource-linux-x86_64-3.5.1.run Then set Kit → Qt version → /opt/qt487/bin/qmake . If you're starting a new project → do not use Qt 4.8.7 .
#include <QApplication> #include <QLabel> int main(int argc, char *argv[])
export QT_X11_NO_MITSHM=1 export XLIB_SKIP_ARGB_VISUALS=1 QString str = "Hello"; QByteArray utf8 = str.toUtf8(); // correct // avoid: str.toAscii() or str.latin1() Missing std::sqrt or C++11 features Qt 4.8.7 expects C++98. Use qSqrt() from <QtGlobal> or #include <math.h> . No automatic high-DPI Use QApplication::setFont(QFont("Arial", 16)) or set environment variable: qt 4.8.7
TEMPLATE = app QT += core gui greaterThan(QT_MAJOR_VERSION, 4): QT += widgets SOURCES += main.cpp Note: QT += widgets is ignored in Qt 4 – keep it for minimal cross-compatibility. | Feature | Qt 4.8.7 | Qt 5/6 | |-----------------------|-------------------------------|-----------------------------| | Widgets module | QtGui | QtWidgets | | QString vs QByteArray | Less efficient Unicode | Better Unicode handling | | OpenGL | QGLWidget | QOpenGLWidget | | Threading | QThread (old style) | Better thread affinity | | Signals/slots | Macro-based (still works) | New syntax (function ptr) | | QML | Qt Quick 1.x (obsolete) | Qt Quick 2.x+ | | Platform plugins | X11, Windows, Cocoa (limited) | Wayland, Direct2D, etc. | 6. Debugging & Common Pitfalls Crash on modern Linux? Qt 4.8.7 uses X11 and older fontconfig. Set:
FROM ubuntu:16.04 RUN apt-get update && apt-get install -y build-essential libgl1-mesa-dev ... ADD qt-everywhere-opensource-src-4.8.7.tar.gz /opt/ WORKDIR /opt/qt-everywhere-opensource-src-4.8.7 RUN ./configure -prefix /usr/local/qt487 ... && make -j4 && make install wget https://download
configure -platform win32-g++ -prefix C:\Qt\4.8.7 mingw32-make mingw32-make install main.cpp
QApplication app(argc, argv); QLabel label("Hello from Qt 4.8.7"); label.show(); return app.exec(); Use qSqrt() from <QtGlobal> or #include <math
qmake -project qmake make ./your_app