uiviewcontroller - Use of undeclared identifier in VC but its declared in the Custom UIImageView -

i'm having trouble use of undeclared identifier. have created custom uiimageview , in have declared @property uilabel 'answelbl'. have imported custom uiimageview.h file viewcontroller.h file whenever try use 'answerlbl' comes error 'use of undeclared identifier'. how stop problem, need use 'answerlbl' in viewcontroller?

this viewcontroller.h

#import <uikit/uikit.h> #import "numberpadimageview.h"    @interface viewcontroller : uiviewcontroller {  numberpadimageview *numberkeyboard;  } 

and here custom uiiimageview => numberpadimageview.h

#import <uikit/uikit.h>  @interface numberpadimageview : uiimageview {  uilabel *answerlbl;  uibutton *onebtn; uibutton *twobtn; uibutton *threebtn; uibutton *fourbtn; uibutton *fivebtn; uibutton *sixbtn; uibutton *sevenbtn; uibutton *eightbtn; uibutton *ninebtn; uibutton *zerobtn;  uibutton *backbtn; uibutton *periodbtn; uibutton *clearanswerfieldbtn;  } @property (nonatomic, strong) iboutlet uilabel *answerlbl;  -(ibaction)buttonpressed:(uibutton *)sender; -(ibaction)backspace:(id)sender; -(ibaction)clearanswerlbl:(id)sender; 

@property (nonatomic, strong) numberpadimageview *imageview; 

in viewdidload,

self.imageview = [[numberpadimageview alloc]init]; 

access by,

self.imageview.answerlbl 

and declare answerlbl property,

@property (nonatomic, strong) uilabel *answerlbl;