c
#include "mainwindow.h"
#include <QApplication>
#include <QMessageBox>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
if(argc > 1){
QMessageBox::information(0,QString("tip"),QString::fromLocal8Bit(argv[1]));
}
MainWindow w;
w.show();
return a.exec();
}

结果

即从main入口进入