Passing data from controllerA to controllerB using delegate - objective-c

Question

I am trying to send simple data from viewControllerA to viewControllerB using delegate but can not find The problem in my code.here is the code
in ViewControllerA.h
#import <UIKit/UIKit.h>
#class ViewControllerA;
#protocol viewControllerADelegate <NSObject>
-(void) addItem: (ViewControllerA *)controller data:(NSString *)item;
#end
#interface ViewControllerA : UIViewController
- (IBAction)buttonPressed:(id)sender;
#property (assign) id<viewControllerADelegate> delegate;
#end
inViewControllerA.m
#import "ViewControllerA.h"
#interface ViewControllerA ()
#end
#implementation ViewControllerA
#synthesize delegate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (IBAction)buttonPressed:(id)sender {
[self.delegate addItem:self data:#"this is data"];
}
#end
and here is ViewControllerB.h
#import <UIKit/UIKit.h>
#import "ViewControllerA.h"
#interface ViewControllerB : UIViewController<viewControllerADelegate>
#end
and ViewControllerB.m
#import "ViewControllerB.h"
#import "ViewControllerA.h"
#interface ViewControllerB ()
#end
#implementation ViewControllerB
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
ViewControllerA *vba = [[ViewControllerA alloc]init];
[vba setDelegate:self];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
-(void) addItem: (ViewControllerA *)controller data:(NSString *)item{
NSLog(#"delegate function called");
}
#end
The implemented function -(void) addItem: (ViewControllerA *)controller data:(NSString *)item is never called.Am I missing something ? Thanks in advance

Answer 1

Are you using storyboards? If yes, you just push the wrong button: storyboard initializes view controllers on its own, so yours code:
ViewControllerA *vba = [[ViewControllerA alloc]init];
[vba setDelegate:self];
just setting delegate on some unused view controller.
Use segues, don't try to reinvent a wheel.