如何为QTreeView项目设置相对于其后缀的自定义图标

#include <QApplication>
#include <QTreeView>
#include <QFileSystemModel>
#include <QFileInfo>
#include <QIcon>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    // 创建QTreeView和QFileSystemModel
    QTreeView treeView;
    QFileSystemModel model;
    model.setRootPath(QDir::currentPath());
    treeView.setModel(&model);

    // 获取文件后缀名并设置自定义图标
    for (int i = 1; i < model.columnCount(); ++i) {
        treeView.setColumnHidden(i, true);
    }

    for (int i = 0; i < model.rowCount(); ++i) {
        QModelIndex index = model.index(i, 0);
        QString filePath = model.filePath(index);
        QFileInfo fileInfo(filePath);
        QString suffix = fileInfo.suffix();

        // 根据后缀名设置自定义图标
        if (suffix == "txt") {
            QIcon icon(":/icons/txt_icon.png");
            model.setData(index, icon, Qt::DecorationRole);
        } else if (suffix == "doc" || suffix == "docx") {
            QIcon icon(":/icons/doc_icon.png");
            model.setData(index, icon, Qt::DecorationRole);
        } else {
            // 设置默认图标
            QIcon icon(":/icons/default_icon.png");
            model.setData(index, icon, Qt::DecorationRole);
        }
    }

    treeView.show();

    return a.exec();
}