ios - I get the error Property '...' not found on object of type '...' -

appdelegate.h

#import <uikit/uikit.h>  @interface appdelegate : uiresponder <uiapplicationdelegate>  @property (strong, nonatomic) uiwindow *window;  @end 

appdelegate.m

#import "appdelegate.h"  #import "firstviewcontroller.h"  #import "secondviewcontroller.h"  @implementation appdelegate  - (bool)application:(uiapplication *)application didfinishlaunchingwithoptions:         goes on normal app.......... @end 

firstviewcontroller.h

#import <uikit/uikit.h>  @interface firstviewcontroller : uiviewcontroller  @property (strong, nonatomic) iboutlet uiimageview *bground;  - (ibaction)settingspressed:(id)sender;  - (ibaction)startpressed:(id)sender;  @end   @class secondviewcontroller;  @interface secondviewcontroller : uiviewcontroller   @property(strong,nonatomic)secondviewcontroller *secondviewcontroller;  @end 

firstviewcontroller.m

#import "firstviewcontroller.h"  @interface firstviewcontroller ()  @end  @implementation firstviewcontroller  - (void)viewdidload { [super viewdidload]; // additional setup after loading view, typically nib. }  - (void)didreceivememorywarning { [super didreceivememorywarning]; // dispose of resources can recreated. }  - (ibaction)settingspressed:(id)sender { 

on line says "property 'secondviewcontroller' not found on object of type 'firstviewcontroller' it's line directly below.

self.secondviewcontroller =  [[secondviewcontroller alloc] initwithnibname:@"secondviewcontroller"                                        bundle:nil]; 

it has same warning last on line below.

[self presentviewcontroller:self.secondviewcontroller animated:yes completion:nil];  }   - (ibaction)startpressed:(id)sender { } @end 

secondviewcontroller.h

#import <uikit/uikit.h>  @interface secondviewcontroller : uiviewcontroller  @end 

secondviewcontroller.m

#import "secondviewcontroller.h"  @interface secondviewcontroller ()  @end  @implementation secondviewcontroller  - (id)initwithnibname:(nsstring *)nibnameornil bundle:(nsbundle *)nibbundleornil { self = [super initwithnibname:nibnameornil bundle:nibbundleornil]; if (self) {     // custom initialization } return self; }  - (void)viewdidload { [super viewdidload]; // additional setup after loading view. }  - (void)didreceivememorywarning { [super didreceivememorywarning]; // dispose of resources can recreated. }  @end 

i'm confused why declaring secondviewcontroller twice. seem both in firstviewcontroler.h , in own .h file. regardless, issue seems have given secondviewcontroller property trying access. reread own code:

@interface secondviewcontroller : uiviewcontroller   @property(strong,nonatomic)secondviewcontroller *secondviewcontroller;  @end 

what want in firstviewcontroller.h file this:

#import <uikit/uikit.h> #import "secondviewcontroller.h" @interface firstviewcontroller : uiviewcontroller  @property (strong, nonatomic) iboutlet uiimageview *bground; @property(strong,nonatomic)secondviewcontroller *secondviewcontroller;  - (ibaction)settingspressed:(id)sender;  - (ibaction)startpressed:(id)sender;  @end 

note import secondviewcontroller @ top of .h file, , declare property inside @interface.