Iphone calendar integrating problem

I am integrating calendar to my application , after adding calendar i am getting error , please help me anyone where it is problem .

"_OBJC_CLASS_$_KalViewController", referenced from:
      objc-class-ref-to-KalViewController in FertilityAppAppDelegate.o

  "_KalDataSourceChangedNotification", referenced from:
      _KalDataSourceChangedNotification$non_lazy_ptr in EventKitDataSource.o

     (maybe you meant: _KalDataSourceChangedNotification$non_lazy_ptr)


  "_OBJC_CLASS_$_EKEventViewController", refer开发者_JAVA百科enced from:
      objc-class-ref-to-EKEventViewController in FertilityAppAppDelegate.o

Verify if you have added the EventKitUI.framework. If yes delete it and add it again.

I added new static library to my application. Now working .