Accessing another viewcontroller - ios

Question

I'm trying to access some things from another viewcontroller (iOS).
I have my ViewController.h:
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController <UITextFieldDelegate> {
...
}
#end
ViewController.m:
#import "ViewController.h"
#import "ViewController2.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
ViewController2.someVar = #"cakes"; // this is where I'm trying to set something in vc2
}
ViewController2.h:
#import <UIKit/UIKit.h>
#interface ViewController2 : UIViewController <UITableViewDataSource, UITableViewDelegate, UISearchDisplayDelegate>
{
...
}
#property (nonatomic, copy) NSString *someVar;
#end
ViewController2.m:
#import "ViewController2.h"
#interface ViewController2 ()
#end
#implementation ViewController2
#synthesize someVar;
etc.
But at the line where I try to access this var, it gives me the following error:
Property 'someVar' not found on object of type 'ViewController2'.
In what way would I achieve accessing this other view controller?

Answer 1

You have to create a ViewControlle2 object in your Viewcontroller.m.
ViewController2 *myVC2 = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
myVC2.someVar = #"cakes";

Answer 2

Another way to do this is by using delegates. If you created ViewController1 in AppDelegate, you should also create ViewController2 in AppDelegate, or where ever you create your ViewControllers. Then you ViewController1 would send a message to AppDelegate to get the data from ViewController2 and vice versa. This makes ViewController1 and ViewController2 no longer dependent on each other.
So in AppDelegate.h we'd have something like this
#interface AppDelegate : NSObject <MyViewControllerDelegate>
#property (nonatomic) ViewController1 *viewController1;
#property (nonatomic) ViewController2 *viewController2;
#end
Then in both view controllers you can add this line in the .h
#property (nonatomic) id<MyViewControllerDelegate> delegate;
This just gives us a variable to use to refer to the delegate from within the ViewController's .m
You also need to create the MyViewControllerDelegate protocol, so in a file called MyViewControllerDelegate.h
#protocol MyViewControllerDelegate
- (ViewController1 *) viewController1;
- (ViewControlelr2 *) viewController2;
#end
Then when you create the ViewControllers in AppDelegate.m, you should also set AppDelegate as the ViewController's delegate.
self.viewController1 = [[ViewController1 alloc] init];
self.viewController1.delegate = self;
self.viewController2 = [[ViewController2 alloc] init];
self.viewController2.delegate = self;
So with all of this delegate set up done, you should be able to access viewController2.someVar from viewController1 through the delegate by using:
self.delegate.viewController2.someVar = #"Cakes";
Hope this isn't too long winded.