如何使用type =“file”为多输入表单创建Code Igniter Controller

Question

我想问一下，如何在CodeIgniter中为这个视图设置控制器功能？

    <form action="<?=base_url()?>posts/new_post" method="post" enctype="multipart/form-data"><br>
     <input type="file" name="before" id="before" ><br>
     <input type="file" name="after" id="after" ><br>
     <input type="text" class="form-control" id="title" name="title" placeholder="Enter name"><br>
     <textarea class="form-control" id="description" name="description" placeholder="Enter name"></textarea><br>
     <input type="submit" value="Submit Profile Picture" name="submit" class="btn btn-primary  ">
    </form>

谢谢