CODEWITHSUNDEEP
iphoneiosobjective-c
James Dunay
James Dunay

Reputation: 2724

Calling method from one Viewcontroller inside another

Noob question fellas, but I cant get it.

I've got a View Controller that loads in a separate View Controller. I would like to be able on a button press to call a method inside the parent View controller. So here is what i've got

parent VC:

   .h
    -(void)callParentMethod;



    .m

    -(void)viewDidLoad{
    self.childVC.parentVC = self;
    }

-(void)callParentMethod{
NSLog(@"Hello?");
}

child VC: 

.h

#import "TheParentViewController.h"

@property (nonatomic, weak) TheParentViewController *parentVC;


.m

-(void)addThis{
[self.parentVC callParentMethod];
}

I get no errors, the child VC method addThis seems to call the method, but the NSLog is never called. Any thoughts what i'm doing wrong?

Upvotes: 2

Views: 1229

Answers (5)

Nikhil Augustine
Nikhil Augustine

Reputation: 197

You can create a property in child view controller say,

@class ParentVC;
@property(weak,nonatomic)ParentVC *parentVCreference;

and get the reference for the Parent view controller as follows

self.parentVCreference=(ParentVC*)self.parentViewController;

then you can call any exposed methods from ParentVC as follows

[self.parentVCreference parentVCMethod];

Note: You need to import header of ParentVC in ChildVC implementation file.

Upvotes: 0

slysid
slysid

Reputation: 5488

Check whether your parent view controller is allocated. 

   parentnvc = [ParentViewController alloc]initWithNibName:@"somenib" bundle:nil];

if parentvc is allocated and initialised and call the method

Upvotes: 0

tomasbasham
tomasbasham

Reputation: 1734

I am not quite sure what your application is, but you should not have to keep a reference to the parent view controller. A UIViewController already has a property called parentViewController which you can use in the following way:

[self.parentViewController methodToCall];

This will call a method on the parent view controller. You may need to cast the object in order to call custom methods

[(TheParentController *)self.parentViewController methodToCall];

This of course assumes that the child view controller's view is a subview of the parent view controller view. Hope this helps

Upvotes: 0

Sviatoslav Yakymiv
Sviatoslav Yakymiv

Reputation: 7935

I think parentVC releases because of weak reference. Try to use this method.

-(void)addThis{
NSLog(@"%@", self.parentVC);
[self.parentVC callParentMethod];
}

Upvotes: 2

Tommy Devoy
Tommy Devoy

Reputation: 13549

YourParentVC *parent = (YourParentVC*)[self presentingViewController];

parent.whatever = blah;

Upvotes: 0

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