int main( /*int argc, char **argv*/int argc, char *argv[] )
{
QApplication mcwApp(argc, argv);
// QApplication *mcwApp = new QApplication(argc, argv);
MWidget manage(1);
manage.show();
return mcwApp.exec();
};
编译没有问题，执行就出错，出错信息：
QApplication::palette() failed: please instantiate the QApplication object first.
QWidget: Must construct a QApplication before a QPaintDevice
