How to launch a ViewController from a Non ViewController class?

Question

the title says it all, i usually open ViewControllers like this

ListingViewController *listingView = [[ListingViewController alloc]init];
[self.navigationController pushViewController:listingView animated:YES];

but on this particular class thats a custom UICollectionView cell i want to launch a new controller based on the cell thats clicked. how can i do that ?

Answer 1

You are looking to add detail views to a cell try this link on Adding Detail Views.Hopefully this Helps

Answer 2

The usual way is to implement the UICollectionViewDelegate method – collectionView:didSelectItemAtIndexPath: in the view controller that contains the UICollectionView. Then you can present the new view controller in the normal way.

For example:

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    [collectionView deselectItemAtIndexPath:indexPath animated:YES];

    MyModel * model = self.listItems[indexPath.row]; //retrieve the object that is displayed by the cell at the selected index

    MyViewerViewController * vc = [[MyViewerViewController alloc] initWithMyModel:model];
    [self.navigationController pushViewController:vc animated:YES];

}

Answer 3

Use the UICollectionViewDelegate method didSelectItemAtIndexPath for doing this and make sure that this delegate method is present in the view controller class implementing the UICollectionView.

Answer 4

You have to notify the ViewController, on cell click, on which UICollectionView exist. and on this controller you can push the desired controller

Answer 5

You need a view controller of some sort for pushing or presenting, there's no way around that.

You shouldn't have a problem accomplishing that and there are a few ways you can do so. First off, you should be able to write this logic in the UICollectionViewDelegate method collectionView:didSelectItemAtIndexPath:. Your delegate is most likely the containing view controller so that may be all you need to do. If however it isn't, just add a view controller property to your delegate that you can use for presenting things. Make it a weak one to avoid a possible retain cycle (where the view controller retains the delegate and the delegate retains the view controller).

Answer 6

self.navigationController can be accessed via only UIViewController's subclass. You want to access UINavigationController from not UIViewcontroller class. Is it what you are asking?

If you have property of UINavigationController at AppDelegate like

@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) UINavigationController *navigationController;
@end

You can get a pointer from wherever you want as below

#import "AppDelegate.h"
AppDelegate *delegate = (AppDelegate *)[[[UIApplication sharedApplication] delegate];
UINavigationController *navigation = [delegate navigationController];

Now you have it.

Answer 7

You need to get the current UIViewController, there are multiple ways to do it. You can parse the VC in your UICollectionViewCell's header file. You can also use self.window.rootviewcontroller.

After that you can just use [VC pushViewController:listingView animated:YES]; or [self.window.rootviewcontroller pushViewController:listingView animated:YES];