mkdir hello

helloworld.cpp

#include <QPushButton>
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QPushButton btn("hello world");
    btn.resize(200,100);
    btn.show();
    return app.exec();
}

　　

qmake –project

生成的是hello.pro

编辑

QT += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

qmake hello.pro

 生成了Makefile

make