/* 显示菜单 */
QMenu * menu = ui->menuButton->getmenu();
//把几种皮肤加进来
//前面加图片后面加文字
b1 = new QAction(QIcon(":/images/menu.png"), tr("&星球皮肤"), this);
b2 = new QAction(QIcon(":/images/menu.png"), tr("&绿草皮肤"), this);
b3 = new QAction(QIcon(":/images/menu.png"), tr("&唯美皮肤"), this);
b4 = new QAction(QIcon(":/images/menu.png"), tr("&秋季皮肤"), this);
b =  new QAction(QIcon(":/images/menu.png"), tr("&原始皮肤"), this);
menu->addAction(b1);
menu->addAction(b2);
menu->addAction(b3);
menu->addAction(b4);
menu->addAction(b);
connect(b1,SIGNAL(triggered(bool)),this,SLOT(bg1()));
connect(b2,SIGNAL(triggered(bool)),this,SLOT(bg2()));
connect(b3,SIGNAL(triggered(bool)),this,SLOT(bg3()));
connect(b4,SIGNAL(triggered(bool)),this,SLOT(bg4()));
connect(b,SIGNAL(triggered(bool)),this,SLOT(bg()));
ui->messageTextEdit->installEventFilter(this);//回车键发消息监听

void Widget::bg1()
{ui->stackedWidget->setStyleSheet("QStackedWidget {background-image: url(:/images/background1.jpg);}");
}
void Widget::bg2()
{ui->stackedWidget->setStyleSheet("QStackedWidget {background-image: url(:/images/background2.jpg);}");
}
void Widget::bg3()
{ui->stackedWidget->setStyleSheet("QStackedWidget {background-image: url(:/images/background3.jpg);}");
}
void Widget::bg4()
{ui->stackedWidget->setStyleSheet("QStackedWidget {background-image: url(:/images/background4.jpg);}");
}
void Widget::bg()
{ui->stackedWidget->setStyleSheet("QStackedWidget {background-image: url(:/images/background.jpg);}");
}

现在点击每个就可以切换壁纸了