QT 实现点击窗口以外任何位置即关闭窗口

bool QTipLabel::eventFilter(QObject *o, QEvent *e)
{
    switch (e->type()) {
#ifdef Q_DEAD_CODE_FROM_QT4_MAC
    case QEvent::KeyPress:
    case QEvent::KeyRelease: {
        int key = static_cast<QKeyEvent *>(e)->key();
        Qt::KeyboardModifiers mody = static_cast<QKeyEvent *>(e)->modifiers();
        if (!(mody & Qt::KeyboardModifierMask)
            && key != Qt::Key_Shift && key != Qt::Key_Control
            && key != Qt::Key_Alt && key != Qt::Key_Meta)
            hideTip();
        break;
    }
#endif
    case QEvent::Leave:
        hideTip();
        break;




#if defined (Q_OS_QNX) // On QNX the window activate and focus events are delayed and will appear
                       // after the window is shown.
    case QEvent::WindowActivate:
    case QEvent::FocusIn:
        return false;
    case QEvent::WindowDeactivate:
        if (o != this)
            return false;
        hideTipImmediately();
        break;
    case QEvent::FocusOut:
        if (reinterpret_cast<QWindow*>(o) != windowHandle())
            return false;
        hideTipImmediately();
        break;
#else
    case QEvent::WindowActivate:
    case QEvent::WindowDeactivate:
    case QEvent::FocusIn:
    case QEvent::FocusOut:
#endif
    case QEvent::Close: // For QTBUG-55523 (QQC) specifically: Hide tooltip when windows are closed
    case QEvent::MouseButtonPress:
    case QEvent::MouseButtonRelease:
    case QEvent::MouseButtonDblClick:
    case QEvent::Wheel:
        hideTipImmediately();
        break;


    case QEvent::MouseMove:
        if (o == widget && !rect.isNull() && !rect.contains(static_cast<QMouseEvent*>(e)->pos()))
            hideTip();
    default:
        break;
    }
    return false;
}

然后在初始化时 注册 eventfilter

    qApp->installEventFilter(this);