拖拽datePicker和TimePicker 到屏幕时报错

Question

我拖拽datePicker和TimePicker 到屏幕，报DatePicker 和TimePicker 类没有找到错误，to parse date_picker_holo.xml文件失败，you must specifiy a valid layout reference.The layout ID @layout/date_picker_selected_date in not valid. 非常头疼，望老师指教，万分感谢！

Answer 1

是不是id那里少码了个加号