最近遇到一些需求。需要在分页输出前对数据进行一些调整，然后再输出分页，找到一个手动对 Collection 分页的方案，下面是示例代码：

// 获取所有用户
$users = User::all();
// 为每个用户添加一个属性
$users->each(function($user) {
  $user->foo = 'bar';
});
// 对数据进行手动分页
$per_page = 5; // 每页显示5条
$users = $this->paginateCollection($users, $per_page);
return View('users', compact('users'));

下面是分页方法：

protected function paginateCollection($collection, $perPage, $pageName = 'page', $fragment = null)
    {
        $currentPage = \Illuminate\Pagination\LengthAwarePaginator::resolveCurrentPage($pageName);
        $currentPageItems = $collection->slice(($currentPage - 1) * $perPage, $perPage)->values();
        parse_str(request()->getQueryString(), $query);
        unset($query[$pageName]);
        $paginator = new \Illuminate\Pagination\LengthAwarePaginator(
            $currentPageItems,
            $collection->count(),
            $perPage,
            $currentPage,
            [
                'pageName' => $pageName,
                'path' => \Illuminate\Pagination\LengthAwarePaginator::resolveCurrentPath(),
                'query' => $query,
                'fragment' => $fragment
            ]
        );

        return $paginator;
    }