QPalette palette;
palette.setBrush(QPalette::Active, QPalette::ButtonText, QBrush(QColor(255,0,0,255)));
palette.setBrush(QPalette::Inactive, QPalette::ButtonText, QBrush(QColor(255,0,0,255)));
palette.setBrush(QPalette::Disabled, QPalette::ButtonText, QBrush(QColor(106, 104, 100, 255)));
setPalette(palette);
设置按钮的字体为红色,这是Qt4的写法!