MainWindow上有一个使用Qfilesystemmodel的QTreeview，实现：当前选中行及下面8行的字体变成蓝色，给出C++完整示例

下面是一个在MainWindow上使用QFileSystemModel和QTreeView实现当前选中行及下面8行的字体变成蓝色的C++示例代码：

#include <QtWidgets>

class MainWindow : public QMainWindow
{
public:
    MainWindow(QWidget *parent = nullptr) : QMainWindow(parent)
    {
        QFileSystemModel *model = new QFileSystemModel;
        model->setRootPath(QDir::currentPath());

        QTreeView *treeView = new QTreeView(this);
        treeView->setModel(model);
        treeView->setSelectionMode(QAbstractItemView::SingleSelection);
        treeView->setSelectionBehavior(QAbstractItemView::SelectRows);
        treeView->setUniformRowHeights(true);
        treeView->setColumnHidden(1, true);
        treeView->setColumnHidden(2, true);
        treeView->setColumnHidden(3, true);

        connect(treeView, &QTreeView::clicked, this, &MainWindow::onTreeViewClicked);

        setCentralWidget(treeView);
    }

private:
    void onTreeViewClicked(const QModelIndex &index)
    {
        QTreeView *treeView = qobject_cast<QTreeView *>(sender());
        if (treeView) {
            QItemSelectionModel *selectionModel = treeView->selectionModel();
            if (selectionModel) {
                QModelIndexList selectedRows = selectionModel->selectedRows();
                QStyleOptionViewItem option = treeView->viewOptions();
                for (const QModelIndex &row : selectedRows) {
                    for (int i = 0; i < 9; ++i) {
                        option.state |= QStyle::State_Selected;
                        option.palette.setColor(QPalette::Text, Qt::blue);
                        treeView->itemDelegate()->paint(nullptr, &option, row);
                        row = row.sibling(row.row() + 1, row.column());
                    }
                }
            }
        }
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

这个示例创建了一个MainWindow，包含一个使用QFileSystemModel作为数据模型的QTreeView，并且实现了点击行时将当前行及下面8行的字体变成蓝色的功能。