int main(int argc, char **argv)
{
 QApplication app(argc, argv);
 QString str1 = "Test";
 QByteArray ba = str1.toLatin1();
 const char *c_str2 = ba.data();
 printf("str2: %s", c_str2);
 return app.exec();
}

QIcon img("/img/ico.bmp");
button.setIcon(img);
button.setIconSize(QSize(button.width(), button.height()));