类似这样的设计, ``` $rules = [ 'rule0'=>['field0', 'validator'], 'rule1'=>['field1', 'validator'], 'rule2'=>['field2', 'validator'] ] $scenes = [ 'scene0'=>['rule0', 'rule3'], 'scene1'=>['rule1', 'rule3'], ] ``` 如此,即可取代on的设计,在使用的时候更加灵活