self.delegate is always nil - ios

Question

I saw similar questions like this. In all the place they said to use className.delegate = self or other similar solutions. But i already checked i have did everything correctly. Then also i am facing self.delegate is nil problem.
I am trying to pass data from MyViewController to NextViewController on Button Click
I did,
1.Created Protocol in MyViewController
2.Created delegate Instance in MyViewController
3.Wrote this code in Button Click Event
-(void)buttnPressed:(id)s{
NextViewController* d=[[NextViewController alloc]init];
if(self.delegate){
NSLog(#"D");
}
if (self.delegate && [self.delegate respondsToSelector:#selector(groupSelected:)]) {
[self.delegate groupSelected:#"df"];
}
[self.navigationController pushViewController:d animated:YES];
}
4.Implemented FirstViewController in NextViewController and set it's delegate
5.Created FirstViewController's instance (inside NextVC) and using that instance i set it's delegate as self
6.Implemented the delegate method in NextVC
I did everything correctly to my knowledge but i did not get the solution. Please help. Thanks for the time. (:
Here is my code
MyViewController.h
#import <UIKit/UIKit.h>
#protocol WatchListDelegate <NSObject>
-(void)groupSelected:(NSString *)grouDetails;
#end
#interface MyViewController : UIViewController
#property (strong,nonatomic) id<WatchListDelegate> delegate;
#end
MyViewController.m
#import "MyViewController.h"
#import "NextViewController.h"
#interface MyViewController ()
#property UIButton *buttonPopUp;
#end
#implementation MyViewController
-(id)init{
self = [super init];
return self;
}
-(void)loadView{
[super loadView];
self.buttonPopUp=[UIButton buttonWithType:UIButtonTypeCustom];
[self.buttonPopUp addTarget:self
action:#selector(buttnPressed:)
forControlEvents:UIControlEventTouchUpInside];
[self.buttonPopUp setTitle:#"Press ME" forState:UIControlStateNormal];
[self.buttonPopUp setBackgroundColor:[UIColor blueColor]];
self.buttonPopUp.frame=CGRectMake(80,180,80,40);
[self.view addSubview:self.buttonPopUp];
}
-(void)buttnPressed:(id)s{
if(self.delegate){
NSLog(#"D");
}
if (self.delegate && [self.delegate respondsToSelector:#selector(groupSelected:)]) {
[self.delegate groupSelected:#"df"];
}
NextViewController* d=[[NextViewController alloc]init];
[self.navigationController pushViewController:d animated:YES];
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
}
#end
NextViewController.h
#import <UIKit/UIKit.h>
#import "MyViewController.h"
#interface NextViewController : UIViewController<WatchListDelegate>
#end
NextViewController.m
#import "NextViewController.h"
#interface NextViewController ()
#end
#implementation NextViewController
-(id)init{
self = [super init];
if(self){
MyViewController *m=[[MyViewController alloc]init];
m.delegate = self;
}
return self;
}
-(void)loadView{
[super loadView];
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
}
-(void)groupSelected:(NSString *)grouDetails{
NSLog(#"groupSelected");
}
#end
Thanks for the time (:

Answer 1

Try This:
-(void)buttnPressed:(id)s{
NextViewController* d= [self.storyboard instantiateViewControllerWithIdentifier:#"VCidentiferFromStoryBoard"];
self.delegate = d;
[self.navigationController pushViewController:d animated:YES];
if (self.delegate && [self.delegate respondsToSelector:#selector(groupSelected:)]) {
[self.delegate groupSelected:#"df"];
}
}

Answer 2

I don't think you need a delegate to pass data, you're trying to pass the string value 'df'? If so you could just create a public property in NextViewController and assign it a value when you create NextViewController in MyViewController?
The delegate is nil, because it does not look like you set it, so in the button pressed logic you would do self.delegate = d;, don't assign the delegate or create MyViewController in the init of NextViewController, then check the delegate and it won't be nil, but I don't think you need the delegate pattern in this case?
Let me know if you need me to clarify or there is something else in particular you need to pass.

Answer 3

Edit your MyViewController.m
#implementation MyViewController
{
NextViewController* nextViewController;
}
Then rewrite the buttnPressed method like below:
-(void)buttnPressed:(id)s
{
if(!nextViewController) // this way only one time NextVC will be created
{
nextViewController = [[NextViewController alloc]init];
[self.navigationController pushViewController:nextViewController animated:YES];
self.delegate = nextViewController;
}
if (self.delegate && [self.delegate respondsToSelector:#selector(groupSelected:)]) {
[self.delegate groupSelected:#"df"];
}
}