@OnClick(R.id.confirmBtn)
 void click_confirm() {
   if (startWeekPicker.getValue() == classEntity.getStartWeek()
       && endWeekPicker.getValue() == classEntity.getEndWeek()) {
     finish();
     return;
   }
   if (isInfoCorrect()) {
     classEntity.setStartWeek(startWeekPicker.getValue());
     classEntity.setEndWeek(endWeekPicker.getValue());
     classManager.update(classEntity);
     showToast("课程始末周已修改");
     setResult(RESULT_OK);
     finish();
   } else {
     showToast("起始周不能大于结束周");
   }
 }