// 这是service层的类

public PageInfo<TUiWork> getAllByPagination(Integer pageNum, Integer pageSize) {

    PageHelper.startPage(pageNum, pageSize);

    List<TUiWork> workList = workMapper.getAll();

    // 问题就在这里，我对workList做了操作

    List<TUiWork> newWorkList = new ArrayList<>();

    for (TUiWork work : workList) {

        List<String> imageUrlList = getImageUrlListByIds(work.getImageId());

        work.setImageUrls(imageUrlList);

        newWorkList.add(work);

    }

    // 把新的list传递给了PageInfo，导致分页不正常

    PageInfo<TUiWork> tUiWorkPageInfo = new PageInfo<>(newWorkList);

    return tUiWorkPageInfo;

}

//创建Page类

Page page = new Page(pageNum, pageSize);

//为Page类中的total属性赋值

int total = list.size();

page.setTotal(total);

//计算当前需要显示的数据下标起始值

int startIndex = (pageNum - 1) * pageSize;

int endIndex = Math.min(startIndex + pageSize,total);

//从链表中截取需要显示的子链表，并加入到Page

page.addAll(list.subList(startIndex,endIndex));

//以Page创建PageInfo

PageInfo pageInfo = new PageInfo<>(page);

return pageInfo;