laravel 5.2版本验证表单bug,alpha_dash/alpha无法验证英文

$data=$request->all();

    $rule=[

        'name' => 'required',

        'ename'=> 'required|alpha_dash',

        'fid'=>'required'

    ];

    $validator = Validator::make($data,$rule);

    $validator->setAttributeNames($this->chkFiled);

    if ($validator->fails()) {

        return back()->withInput()->withErrors($validator);

    }