access to property of another class - objective-c

Question

How can I access to ViewController property from another class ?
(the ViewController was created by XCode)
this is code of ViewController.h:
#import <UIKit/UIKit.h>
#import "AppDelegate.h"
#interface ViewController : UIViewController{
AppDelegate *appDelegate; //il delegate disponibile per tutta la classe
int numPag; //indice array (sulle pagine html da visualizzare)
NSString *path;
NSURL *baseURL;
NSString *file;
NSString *contentFile;
}
- (IBAction)sottrai:(id)sender;
- (IBAction)aggiungi:(id)sender;
#property (strong, nonatomic) IBOutlet UILabel *valore;
#property (strong, nonatomic) IBOutlet UIWebView *web;
#end
thanks!
[EDIT]
I use Xcode 4.3.2 and the code of AppDelegate.m not find something like:
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
Now, I put in the method didFinishLaunchingWithOptions:(into AppDelegate.m) this code:
viewController = [[UIViewController alloc] initWithNibName:#"ViewController" bundle:nil];
[viewController.web loadHTMLString:contentFile baseURL:baseURL];
adding in the file AppDelegate.h the variable viewController:
#import <UIKit/UIKit.h>
#interface AppDelegate : UIResponder <UIApplicationDelegate>{
NSArray *pageInItalian;
NSArray *pageInEnglish;
UIViewController *viewController;
}
#property (strong, nonatomic) NSArray *pageInLanguage;
#property (strong, nonatomic) UIWindow *window;
#end
I did it correctly? the error is: Property 'web' not found on object of type 'UIViewController *'

Answer 1

I think this post might answer your question
How can I access variables from another class?
You need to make your variable accessible from foreign classes (with #property and #synthesize) and then your foreign class need to know your instance of ViewController
[EDIT]
In your AppDelegate.m, there must be a line like this one :
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
This is where your ViewController is instantiate. From there, you can access every property of your ViewController.
[EDIT]
You need to add the following at the beginning of your implementation
#implementation ViewController
#synthesize web;