property 'scrollView' requires method '-scrollView' to be defined - use @synthesize, @dynamic or provide a method implementation?

what does this mean??

property 'scrollView' requires method '-scrollView'开发者_Go百科 to be defined - use @synthesize, @dynamic or provide a method implementation?

it tells me that on the same line as @end

#import <UIKit/UIKit.h>

@class ViewScrollViewController;

@interface ViewScrollAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    ViewScrollViewController *viewController;
    UIScrollView *scrollView;
    UITextView *textView;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet ViewScrollViewController *viewController;
@property (nonatomic, retain) IBOutlet UIScrollView *scrollView;
@property (nonatomic, retain) IBOutlet UITextView *textView;

@end

Are you synthesizing the property?

Like this..

//your .h file...
@interface myViewController:UIViewController{
    ScrollView *scrollView;
}
@property(nonatomic,retain)ScrollView *scrollView;
@end


//your .m file

@implementation myViewController
@synthesize scrollView;        //are you doing this?

...
...
...
@end

Edit : code snippets based on askers edited question..

In your .m file..

@implementation ViewScrollAppDelegate

@synthesize scrollView,window,viewController,textView;

//Now your implementation..
...
..
@end