以下是我完整的控制器，大家可以参考一下，因为只是简单地实现功能，所以很多东西没有写得严谨，大家可以根据思路写自己的功能。

<?php
// 后台用户模块
class FileAction extends CommonAction {
    protected $tableName = 'userfiles';

    public function index(){
        $M = M($this->tableName);

        $typeArr = array('1'=>'图片', '2'=>'flash');

        $map = array();
        $count      = $M->where($map)->count();

        import('ORG.util.Page');// 导入分页类
        $Page       = new Page($count,20);
        $show       = $Page->show();

        $list = $M->where($map)->order('id DESC')->limit($Page->firstRow.','.$Page->listRows)->select();
        foreach($list as $key=>$val){
            $list[$key]['exist'] = file_exists('.'.$val['path']) ? '正常' : '<span class=\'red\'>文件丢失</span>';
            $list[$key]['typename'] = $typeArr[$val['type']];
        }

        $this->assign('list',$list);
        $this->assign('page',$show);
        $this->assign('typeList',$typeList);
        $this->display();

    }


    public function add(){
        $M = M($this->tableName);
        if(IS_POST){
            //$data = $_POST['data'];    //将表单传过来的data值赋予data数组
            $id = I('id');
            $hiddenFilePath = I('hiddenFilePath');    //隐藏文件路径 更新时用于删除文件用
            $data['filename'] = I('name');
            $data['type'] = I('type');
            $data['remark'] = I('remark');

            //获取上传文件信息
            $fileInfo = $this->getFileInfo($data['type']);
            if( empty($id) && empty($fileInfo) ){
                $this->ajaxReturn(array('status'=>1, 'info'=>'操作成功'));

            }elseif( !empty($fileInfo) ){

                //如果文件不为空，则将文件信息赋予DATA数组
                $data['savepath'] = $fileInfo['savepath'];
                $data['extension'] = $fileInfo['extension'];
                $data['size'] = $fileInfo['size'];
                $data['savename'] = $fileInfo['savename'];
            }
            if( empty($data['filename']) ){
                $data['filename'] = $fileInfo['name'];
            }
            $data['user_id'] = $this->userId;
            $data['create_time'] = NOW_TIME;


            if(!$id){

                //添加
                $M->add($data);
                $result = array('status'=>1, 'info'=>'操作成功');
            }else{
                if($data['savepath']){
                    $thumb = getImgThumb($hiddenFilePath);
                    if( file_exists('.'.$hiddenFilePath) ) unlink ('.'.$hiddenFilePath); //删除已经存在的文件，重新上传新文件
                    if( file_exists('.'.$thumb) ) unlink ('.'.$thumb);
                }

                $M->where('id='.$id)->save($data);
                $result = array('status'=>1, 'info'=>'操作成功');
            }
            $this->ajaxReturn($result);
        }else{
            $id = I('id');
            if( !empty($id) ){
                $info = $M->where('id='.$id)->find();
                $this->assign('info',$info);
            }
            $this->display();
        }

    }

    public function del(){
        $M = M("File");
        $id = $_REQuEST['id'];
        $map['id'] = array('eq',$id);
        $savepath = $M->where($map)->getField('savepath');
        if(file_exists(WEB_ROOT.$savepath)) unlink(WEB_ROOT.$savepath);
        $delNum = $M->where($map)->delete();
        if(!empty($delNum)){
            $this->ajaxReturn(1,'成功删除'.$delNum.'条数据！',1);
        }else{
            $this->ajaxReturn(0,'删除失败！',0);
        }
    }

    public function updateSort(){
        $idArr = $_POST['idArr'];
        $sortArr = $_POST['sortArr'];

    }

    public function getFileInfo($type=1){
        if( empty($_FILES) ) return false;
        //$uploadFileName = date('YmdHis').rand(1000,9999);
        if($type==1){
            $extendPath = 'images/'.date(Ymd).'/';
        }else{
            $extendPath = 'flash/'.date(Ymd).'/';
        }

        import('ORG.Net.uploadFile');
        $upload = new uploadFile();// 实例化上传类
        //$upload->saveRule = $uploadFileName;
        $upload->maxSize  = 3145728 ;// 设置附件上传大小
        $upload->allowExts  = array('jpg', 'gif', 'png', 'jpeg','doc','wps','xls','csv','rar','tar','txt');// 设置附件上传类型
        $upload->savePath =  './uploads/'.$extendPath;

        $upload->thumb = true;
        $upload->thumbMaxWidth = '50,200';
        $upload->thumbMaxHeight = '50,200';
        $upload->thumbPrefix = 'small_';

        if(!$upload->upload()) {// 上传错误提示错误信息
            $this->ajaxReturn(0,$upload->getErrorMsg(),0);
        }else{
            $fileInfo =  $upload->getuploadFileInfo();
            $fileInfo[0]['savepath'] = '/uploads/'.$extendPath.$fileInfo[0]['savename'];
        }
        return $fileInfo[0];
    }

    public function downloadFile(){
        $M = M($this->tableName);
        $map['id'] = I('fileId');
        $info = $M->where($map)->find();
        $filepath = '.'.$info['path'];
        if( !file_exists($filepath) ){
            echo '文件不存在！';
            exit;
        }

        //$M->where($map)->setInc('download');
        $file = fopen($filepath,"r"); // 打开文件
        // 输入文件标签
        Header("Content-type: application/octet-stream");
        Header("Accept-Ranges: bytes");
        Header("Accept-Length: ".filesize($filepath));
        Header("Content-Disposition: attachment; filename=" . $info['savename']);
        // 输出文件内容
        echo fread($file,filesize($filepath));
        fclose($file);
        exit;
    }

    public function getDownloadNum(){
        $M = M($this->tableName);
        $where['id'] = (int)$_REQuEST['id'];
        $downloadNum = $M->where($where)->getField('download');
        $this->ajaxReturn($downloadNum,'获取成功！',1);
    }


}