先看效果

编辑：已添加虚拟键盘辅助输入，添加二维码识别，用的QZxing

初始化

    auto mainLayout = new QHBoxLayout(this);m_viewfinder = new QCameraViewfinder(this);m_viewfinder->setStyleSheet("border-radius: 20px;background-color:rgb(43,48,70)");mainLayout->addWidget(m_viewfinder,8);

选择相机

void cameraeidget::selectDevice(const QCameraInfo &cameraInfo)
{bool restart = isStarted();if (isStarted()) {stop();}if (m_camera) {