https://blog.csdn.net/fm0517/article/details/4805462
ui.label是QLabel
ui.label_4->setText("some text");
//设置字号
QFont ft;
ft.setPointSize(12);
ui.label_4->setFont(ft);
//设置颜色
QPalette pa;
pa.setColor(QPalette::WindowText,Qt::red);
ui.label_4->setPalette(pa);