功能（上传、取消上传、下载）

上传

    public function enclosureUploadAction()
    {
        $dir = $_SERVER['DOCUMENT_ROOT'] . "/upload/work_flie/";
        $file_info = $_FILES['file'];
        $file_error = $file_info['error'];
        if (!is_dir($dir)) {
            mkdir($dir, 0777, true);
        }
        $arr = [
            'info' => '',
            'status' => -1,
            'url' => ''
        ];
        if ($file_error == 0) {
            $file_only = time() . '-' . mt_rand(100, 99999) . '-' . $file_info['name'];
            if (move_uploaded_file($file_info['tmp_name'], $dir . $file_only)) {
                $file_path = '/upload/work_file/' . $file_only;
                $arr['info'] = '上传成功';
                $arr['status'] = 200;
                $arr['url'] = $file_path;
                //添加记录
                $work_closure_model = new WorkenclosureModel();
                $file_res = $work_closure_model->where('file_path = ?', $file_path)->select()->fetchAll();
                if ($file_res) {
                    $arr['info'] = '该文件已经存在在数据库了，不能重复添加';
                    $this->ajaxReturn($arr);
                }
                $work_closure_model->work_id = 0;
                $work_closure_model->file_path = $file_path;
                $work_closure_model->status = 0;
                $work_closure_model->c_time = time();
                $work_closure_model->add();
            } else {
                $arr['info'] = '上传失败';
            }
            $this->ajaxReturn($arr);
        } else {
            switch ($file_error) {
                case 1:
                    $arr['info'] = '上传文件超过了PHP配置文件中upload_max_filesize选项的值';
                    break;
                case 2:
                    $arr['info'] = '超过了表单max_file_size限制的大小';
                    break;
                case 3:
                    $arr['info'] = '文件部分被上传';
                    break;
                case 4:
                    $arr['info'] = '没有选择上传文件';
                    break;
                case 6:
                    $arr['info'] = '没有找到临时文件';
                    break;
                case 7:
                case 8:
                    $arr['info'] = '系统错误';
                    break;
            }
            $this->ajaxReturn($arr);
        }
    }

取消上传

public function cancelEnclosureUploadAction()
    {
        $file_name = get('file_name', null);
        $arr = [
            'info' => '',
            'status' => -1,
        ];
        if (empty($file_name)) {
            $arr['info'] = '请选择取消上传的文件';
            $this->ajaxReturn($arr);
        }
        $dir = $_SERVER['DOCUMENT_ROOT'] . "/upload/work_flie/";
        $del_name = $dir . $file_name;
        if (file_exists($del_name)) {
            $res = unlink($del_name);
            if ($res) {
                $arr['status'] = 200;
                $arr['info'] = '删除成功';
                //删除记录
                $name = "/upload/work_flie/".$file_name;
                $work_closure_model = new WorkenclosureModel();
                $work_closure_model->where('file_path = ?', $name)->delete();
            } else {
                $arr['info'] = '操作失误导致文件无法删除或文件无法删除';
            }
        } else {
            $arr['info'] = '无法到该文件或者已经被删除了';
        }
        $this->ajaxReturn($arr);
    }

下载

    //下载接口
    public function downloadEnclosureAction()
    {
        $file = get('file_name',null);
        if(!$file){
            return '请传入文件名';
        }
        $file_lj = $_SERVER['DOCUMENT_ROOT'] . "/upload/work_flie/";
        $files = $file_lj . $file;
        if (!file_exists($files)) {
            return "文件不存在";
        } else {
            //打开文件
            $file1 = fopen($files, "r");
            //输入文件标签
            Header("Content-type: application/octet-stream");
            Header("Accept-Ranges: bytes");
            Header("Accept-Length: " . filesize($files));
            Header("Content-Disposition: attachment; filename=" . $file);
            echo fread($file1, filesize($files));
            fclose($file1);
        }
    }