1

我有一个带有QMdiArea. 在当前活动的子窗口中，有一些传入和传出信号连接到小部件。每当活动子窗口更改时，我想断开与先前活动小部件的所有连接并连接到新激活的小部件。像这样：

//Function connected to QMdiArea::subWindowActivated...
void
MainWindow::SubWindowActivated(QMdiSubWindow* subWindow)
{
    auto activeWidget{ qobject_cast<MyWidget*>(subWindow->widget()) };
    if (activeWidget == mPreviouslyActiveWidget)
    {
        return;
    }

    //disconnect all incoming and outgoing signals between previously active widget and this.
    disconnect(this, nullptr, mPreviouslyActiveWidget, nullptr); 
    disconnect(mPreviouslyActiveWidget, nullptr, this, nullptr);

    //re-establish connections to activeWidget ... removed for brevity
    mPreviouslyActiveWidget = activeWidget;
}

子窗口可能发生更改，因为先前的子窗口已被用户关闭，因此不再存在/被QMdiArea. 在这种情况下，我将调用mPreviouslyActiveWidget指向已删除对象的断开连接函数。这是一个问题吗？调用会简单地失败并返回false还是未定义？

4

0 回答 0