Calling method from one Viewcontroller inside another

Question

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?

http://stackoverflow.com/questions/8055052/call-a-parent-view-controller-through-a-navigationcontroller/8055480#8055480 — user523234, Sep 17 '13 at 03:45

score 2 · Accepted Answer · answered Sep 16 '13 at 17:06

2

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

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

answered Sep 16 '13 at 17:06

Sviatoslav Yakymiv

7,887
2
23
43

score 0 · Answer 2 · answered Sep 16 '13 at 17:04

0

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

parent.whatever = blah;

answered Sep 16 '13 at 17:04

Tommy Devoy

13,441
3
48
75

score 0 · Answer 3 · answered Sep 16 '13 at 17:25

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

score 0 · Answer 4 · answered Sep 16 '13 at 17:47

0

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

answered Sep 16 '13 at 17:47

slysid

5,236
7
36
59

score 0 · Answer 5 · answered Nov 24 '15 at 04:59

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.

Calling method from one Viewcontroller inside another

5 Answers5