从Storyboard获取ViewController

Question

I have two ViewControllers, which aren`t (directly) connected with a Segue. But I want to change a String in the second VC, which i get in the first one. My try was:

    #import "secondViewController.h"

    @interface firstViewController ()
    @property NSString* originalString;
    @end

    @implementation firstViewController

    -(void)viewDidDisappear:(BOOL)animated{
        [super viewDidDisappear:animated];
        secondViewController* svc = [secondViewController new];
        svc.anotherString = self.originalString;    
    }

But it dosent work, because I've only created a instance of the second VC, so the value was not saved. Also I can`t use the Storyboard ID, because I use Xcode 5.

I have a menuVC from which you can get to the firstVC and the secondVC. And from the firstVC I can go back (with the navigationbackbarbutton) to the menu. so: menu->firstVC->menu. menu->secondVC->...->menu

My try with StoryboardID:

    -(void)viewDidDisappear:(BOOL)animated{
        [super viewDidDisappear:animated];

        secondViewController* svc =[[UIStoryboard storyboardWithName:@"MainStoryboard_iPhone" bundle:nil] instantiateViewControllerWithIdentifier:@"secondVCSrorybradID"];

        svc.anotherString = self.originalString;    
    }

Answer 1

you can pass the string to second view controller with this code.

secondViewController* svc =[self.storyboard instantiateViewControllerWithIdentifier:@"Your Second VC's Storyboad ID"];
svc.anotherString = self.originalString;    
[self presentViewController:svc animated:YES completion:nil];

//you have to create anotherString property in second View Controller's .h File.

now you can get the string of originalString to second VC. Now you can get this value back second VC to first VC.

hope this helps you.

Answer 2

You should pass your data successively through your UIViewController s navigation. If, for example, you have a navigation like FirstVC > SecondVC > ThirdVC :

In your FirstVC.m, use :

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    ((SecondVCClass*) segue.destinationViewController).secondVCString = _firstVCString;
}

With secondVCString being a @property in your second ViewController.

In your SecondVC.m, use :

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    ((ThirdVCClass*) segue.destinationViewController).thirdVCString = _secondVCString;
}

With of course thirdVCString being a @property in your third ViewController.

---

Edit:

As you updated your question, here is what I suggest :

• In your MenuVC, add this :

   @property (nonatomic, weak) NSString *importantString; 

• In your FirstVC and SecondVC, add this :

   @property (nonatomic, weak) MenuVCClass *menu; 

• When you push to FirstVC or SecondVC, use prepareForSegue to set the destination's view controller menu property to your menu :

   -(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { if ([segue.identifier isEqualToString:@"FirstSegue"]) ((FirstVC*) segue.destinationViewController).menu = self; else if ([segue.identifier isEqualToString:@"SecondSegue"]) ((SecondVC*) segue.destinationViewController).menu = self; } 

• In FirstVC or SecondVC, you can change the NSString value from your menu using _menu.importantString = @"";

Answer 3

You should never use new to create a view controller.

If you're using storyboards but not using segues, you can still create a view controller from the storyboard and invoke it.

Use the method instantiateViewControllerWithIdentifier: to create an instance of the target view controller. The set the properties you want to set, and finally make a call to display it (present it modally, push it onto the navigation stack, or whatever is appropriate for your program.)