1、左边：

示例代码：

 CDockManager::setConfigFlags(CDockManager::DefaultOpaqueConfig);
    CDockManager::setConfigFlag(CDockManager::FocusHighlighting, true);
    dockManager = new CDockManager(this);
    // Disabling the Internal Style Sheet
    dockManager->setStyleSheet("");

    auto previewDockWidget = new CDockWidget("preview", dockManager);
    auto editWidget = new EditWidget(this);
    previewDockWidget->setWidget(editWidget);

    dockManager->addDockWidget(ads::LeftDockWidgetArea, previewDockWidget);

    auto previewDockWidget1 = new CDockWidget("preview111", dockManager);
    auto editWidget1 = new EditWidget1(this);
    previewDockWidget1->setWidget(editWidget1);
    dockManager->addDockWidget(ads::LeftDockWidgetArea, previewDockWidget1);

    auto previewDockWidget2 = new CDockWidget("preview112", dockManager);
    auto editWidget2 = new EditWidget2(this);
    previewDockWidget2->setWidget(editWidget2);
    dockManager->addDockWidget(ads::LeftDockWidgetArea, previewDockWidget2);

2、左边：

CDockManager::setConfigFlags(CDockManager::DefaultOpaqueConfig);
    CDockManager::setConfigFlag(CDockManager::FocusHighlighting, true);
    dockManager = new CDockManager(this);
    // Disabling the Internal Style Sheet
    dockManager->setStyleSheet("");

    auto previewDockWidget = new CDockWidget("preview", dockManager);
    auto editWidget = new EditWidget(this);
    previewDockWidget->setWidget(editWidget);

    dockManager->addDockWidget(ads::TopDockWidgetArea, previewDockWidget);

    auto previewDockWidget1 = new CDockWidget("preview111", dockManager);
    auto editWidget1 = new EditWidget1(this);
    previewDockWidget1->setWidget(editWidget1);
    dockManager->addDockWidget(ads::TopDockWidgetArea, previewDockWidget1);

    auto previewDockWidget2 = new CDockWidget("preview112", dockManager);
    auto editWidget2 = new EditWidget2(this);
    previewDockWidget2->setWidget(editWidget2);
    dockManager->addDockWidget(ads::TopDockWidgetArea, previewDockWidget2);