在任务栏图标上显示红点

关键类：QWinTaskbarButton

#include <QWinTaskbarButton>QPointer<QWinTaskbarButton> taskbarBtn = nullptr;
if (!taskbarBtn) {taskbarBtn = new QWinTaskbarButton(window);taskbarBtn->setWindow(window->windowHandle());
}if (checked) {QPixmap pixmap(10, 10);pixmap.fill(Qt::transparent);QPainter painter(&pixmap);painter.setRenderHint(QPainter::Antialiasing);painter.setPen(Qt::NoPen); // 不绘制边框painter.setBrush(Qt::red);painter.drawEllipse(2, 2, 8, 8);QIcon icon(pixmap);taskbarBtn->setOverlayIcon(icon);
}
else {taskbarBtn->clearOverlayIcon();
}

UI可以参考OBS录制开启。checked为true显示红点，false不显示红点。
使用QWinTaskbarButton::setOverlayIcon设置覆盖图标

在系统托盘上显示红点

关键类：QSystemTrayIcon

    if (visible) {QPixmap pixmap;if (!pixmap.load(":/res/logo.png")) {qDebug() << "Failed to load icon from resource file.";return;}pixmap = pixmap.scaled(16, 16);QPainter painter(&pixmap);painter.setRenderHint(QPainter::Antialiasing);painter.setPen(Qt::NoPen); // 不绘制边框painter.setBrush(Qt::red);painter.drawEllipse(0, 8, 8, 8);QIcon icon(pixmap);setIcon(icon);}else {setIcon(QIcon(":/res/logo.png"));}

先将logo加载到QPixmap，再在QPixmap上用QPainter绘制红点。最后调用QSystemTrayIcon::setIcon