qt生成圆形图片并实现自动旋转，类似音乐播放器中旋转专辑封面

#include "RoundImageWidget.h" #include <QTimer> #include <QPainter> #include <QDebug> RoundImageWidget::RoundImageWidget(QWidget *parent) : QWidget(parent) { m_rotateAngle = 0.0; QString backgroundImageName(":/Images/thumb.jpg"); bool isLoadOk = m_backgroundImage.load(backgroundImageName); if (!isLoadOk) { qDebug()<< "load" << backgroundImageName << "failed !"; } } void RoundImageWidget::startRotateAnimation() { if (nullptr == m_timer) { // 通过定时器去旋转图片，可根据自身需求去设定旋转速度 int speed = 150; qreal angle = 1.0; m_timer = new QTimer(this); m_timer->setInterval(speed); connect(m_timer, &QTimer::timeout, [=]() { m_rotateAngle += angle; if (m_rotateAngle > 360.0) { m_rotateAngle = angle; } repaint(); }); } m_timer->start(); } void RoundImageWidget::paintEvent(QPaintEvent *event) { Q_UNUSED(event); if(!m_backgroundImage.isNull()){ // 中心点 int centerPosW = width() >> 1; int centerPosH = height() >> 1; QPainter painter(this); painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform); // 把自身截取为圆形 QPainterPath path; int round = qMin(width(), height()); path.addEllipse(0, 0, round, round); painter.setClipPath(path); // 设置中心点为起点 painter.translate(centerPosW, centerPosH); // 开始旋转 painter.rotate(m_rotateAngle); // 恢复起点位置，即左上角(0，0) painter.translate(-centerPosW, -centerPosH); // 绘制图片 painter.drawPixmap(-1, -1, width()+2, height()+2, m_backgroundImage); } }