QT显示歌词渐变

显示歌词渐变"/>

QT显示歌词渐变

       central = new QWidget(this);setCentralWidget(central);central->setAutoFillBackground(true);central->setWindowOpacity(1);label = new QLabel(tr("这是一首歌，请你记住它，不要忘记"),central);label2 = new QLabel(central);label2->move(100, 150);label2->resize(500,50);label->move(100, 150);label->resize(500,50);QFont ft;ft.setPointSize(15);label->setFont(ft);label->setAttribute(Qt::WA_TranslucentBackground);label2->setFont(ft);label2->setAttribute(Qt::WA_TranslucentBackground);str = tr("这是一首歌，请你记住它，不要忘记");count=1;QTimer *timer = new QTimer(this);connect(timer, SIGNAL(timeout()), this, SLOT(paint()));timer->start(1000);

void label_test::paint()
{count++;update();qDebug()<<count;
}void label_test::paintEvent(QPaintEvent *e)
{QLinearGradient linearGrad(QPointF(100, 150), QPointF(200, 200));linearGrad.setColorAt(0, Qt::red);linearGrad.setColorAt(0.5, Qt::yellow);linearGrad.setColorAt(1, Qt::green);QBrush brush(linearGrad);QPalette palette;palette.setBrush(QPalette::WindowText, brush);int length = str.length();if(count > length){count = 1;}label2->setPalette(palette);//label->setText("");QString s = str.mid(0, count);label2->setText(s);label2->show();}

主要思路是用两个qlabel 控件，第二个QLabel控件每次都重新绘制第一个QLabel.

repaint会自动调用paintEvent函数