QT显示歌词渐变

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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);

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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