how to give action to UIButtoun Outlet from another UIViewController - objective-c

Question

I have two UIViewController class with names : (RootViewController & SecondViewController).
I have one UIButton Outlet in my SecondViewController.now I want give action method to my UIButton in RootViewController.but I don't know about it.
please guide me and tell me how to get my UIButton in another View and give action method on it in another View....

Answer 1

I'm not sure why you are doing this, it doesn't look good.
Anyway, here's the way.
SecondViewController.h
#interface SecondViewcontroller:UIViewController
#property (nonatomic, weak) IBOutlet UIButton *theButton;
#end
RootViewController.m
SecondViewContoller * sv = [[SecondViewController alloc] init];
[sv.theButton addTarget:self action:#selector(buttonHandler:) forControlEvents:UIControlEventTouchUpInside];
You have to removeTarget when you've done with the button.
Why don't you use delegate or block callback?
ADDED
delegate
SecondViewController.h
#protocol SecondViewControllerDelegate <NSObject>
- (void)theButtonPressed;
#end
#interface SecondViewController : UIViewController
#property (nonatomic, strong) id<SecondViewControllerDelegate>delegate;
#end
SecondViewController.m
#interface SecondViewController ()
{
UIButton *theButton;
}
#end
#implementation SecondViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[theButton addTarget:self.delegate action:#selector(theButtonPressed) forControlEvents:UIControlEventTouchUpInside];
}
#end
RootViewcontroller.h
#interface RootViewController : UIViewController <SecondViewControllerDelegate>
#end
RootViewController.m
SecondViewController *sv = [[SecondViewController alloc] init];
[sv setDelegate:self];
and
- (void)theButtonPressed
{
}
block
SecondViewController.h
typedef void(^TheButtonTouched)(void);
#interface SecondViewController : UIViewController
- (void)addButtonEvent:(TheButtonTouched)event;
#end
SecondViewController.m
#interface SecondViewController ()
{
UIButton *theButton;
TheButtonTouched buttonBlock;
}
#end
#implementation SecondViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// button alloc init here and..
[theButton addTarget:self action:#selector(buttonEvent:) forControlEvents:UIControlEventTouchUpInside];
}
- (void)buttonEvent:(UIButton *)sender
{
if(buttonBlock)
{
buttonBlock();
}
}
- (void)addButtonEvent:(TheButtonTouched)event
{
buttonBlock = event;
}
#end
RootViewController.m
SecondViewController *sv = [[SecondViewController alloc] init];
[sv addButtonEvent:^{
// ADD SOMTHING HERE
}];

Answer 2

You need to create the button's iboutlet property.
Than using object of secondclass.button name you can assign selector.
[classobjectname..btnname addTarget:objectname.class action:#selector(objectname.methodname:);

Answer 3

Just Create RootViewController 's Object and passed into target parameter.
e.g.
[btnShow addTarget:self.rootCtrlObj action:#selector(viewPhoto_click:)
forControlEvents:UIControlEventTouchUpInside];
where rootCtrlObj is #property inside SecondViewController.h file
and when you push this controller in RootViewController you have to pass reference of RootViewController .
For Example,
secVCObj.rootCtrlObj = self;
[self.navigationController pushViewController:secVCObj animated:YES];

Answer 4

as i said custom delegate methods will work perfect for these cases,
in SecondViewController.h file define a custom delegate method like below
#import <UIKit/UIKit.h>
#import "ViewController.h"
#protocol SecondControllerDelegate<NSObject>
- (void)someActionToPerformInRootController;
#end
#interface SecondViewController : UIViewController
#property (nonatomic, assign) id<SecondControllerDelegate>delegate; //declare a custom delegate
#end
in SecondViewController.m file lets take an action of some button
- (IBAction)myButtonActionMethod:(id)sender
{
if([self.delegate respondsToSelector:#selector(someActionToPerformInRootController)])
{
[self.delegate someActionToPerformInRootController]; //this will call the delegate method in first view conroller( root view controller) //do what ever u want t do in the action method of rootviewcontroller
}
}
in RootViewController.h file
#import "SecondViewController.h"
#interface RootViewController : UIViewController < SecondControllerDelegate> //confirmas to delegate
in RootViewController.m while presenting the SecondViewController set the delegate to self
- (IBAction)showAction:(id)sender
{
SecondViewController *secondController = [[SecondViewController alloc]initWithNibName:#"SecondViewController" bundle:nil];
secondController.delegate = self; //call back to this controller
[self presentViewController:secondController animated:YES completion:nil];
}
//this method called from the secondViewcontroller
- (void) someActionToPerformInRootController
{
NSLog(#"perform action in root view controller");
}