Question

So we have recently started developing applications for the iPad for our company. Unfortunately none of us here have ever done any iPhone/iPad development so we are just kind of learning on the fly and winging it. Basically our problem is happening when we try to push a view onto the screen when a table row is clicked. Neither of us can figure out why it’s not doing it because the code looks 100% correct by anything we can tell. Here is what the didRowSelectedAtIndex: method looks like:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    // Navigation logic -- create and push a new view controller

 if(pdvController == nil)
  pdvController = [[PersonDetailViewController alloc] initWithNibName:@"PersonDetailView" bundle:[NSBundle mainBundle]];

 Person *aPerson = [appDelegate.people objectAtIndex:indexPath.row];

 pdvController.aPerson = aPerson;

 [self.appDelegate.navigationController pushViewController:pdvController animated:YES];
}

and here is the header for the toolbarSearchViewController:

  #import <UIKit/UIKit.h>

    #import "RecentSearchesController.h"
    #import "PersonDetailViewController.h"

    @class ToolbarSearchAppDelegate, PersonDetailViewController;

    @interface ToolbarSearchViewController : UIViewController <UISearchBarDelegate, UIPopoverControllerDelegate, RecentSearchesDelegate> {

     ToolbarSearchAppDelegate *appDelegate;

        UIToolbar *toolbar;
        UISearchBar *searchBar;
     UITableView *resultsTable;

        PersonDetailViewController *pdvController;
        RecentSearchesController *recentSearchesController;

     UITableViewController *resultsTableController;
        UIPopoverController *recentSearchesPopoverController; 

    }


    @property (nonatomic, retain) IBOutlet UIToolbar *toolbar;
    @property (nonatomic, retain) UISearchBar *searchBar;
    @property (nonatomic, retain) IBOutlet UITableView *resultsTable;

    @property (nonatomic, retain) ToolbarSearchAppDelegate *appDelegate;
    @property (nonatomic, retain) PersonDetailViewController *pdvController;
    @property (nonatomic, retain) UITableViewController *resultsTableController;
    @property (nonatomic, retain) RecentSearchesController *recentSearchesController;
    @property (nonatomic, retain) UIPopoverController *recentSearchesPopoverController;



    @end

and the ToolbarSearchAppDelegate header:

#import <UIKit/UIKit.h>

@class ToolbarSearchViewController;

@interface ToolbarSearchAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    ToolbarSearchViewController *viewController;
 UINavigationController *navigationController;


 NSMutableArray *people;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet ToolbarSearchViewController *viewController;
@property (nonatomic, retain) IBOutlet UINavigationController *navigationController;

@property (nonatomic, retain) NSMutableArray *people;

@end

and finally the personDetailController.h:

#import <UIKit/UIKit.h>

@class Person;

@interface PersonDetailViewController : UIViewController {

 IBOutlet UITableView *tableView;

 Person *aPerson;
}

@property (nonatomic, retain) Person *aPerson;
@property (nonatomic, retain) UITableView *tableView;

@end

We are getting pretty annoyed because neither of us can figure out why it’s not loading and any help or insight you guys could provide would be amazing. I wasn’t sure what you may need to see, so if you need anything more specific, let me know and I will post it. Thanks!

ps. I am not sure how the code tags are going to handle all of Obj-c’s quirky syntax, so if you see syntax errors, just ignore them. Assume that it is syntactically correct and will compile and run…

Answer 1

This line looks a little odd:

[self.appDelegate.navigationController pushViewController:pdvController animated:YES];

try and make it

[self.navigationController pushViewController:pdvController animated:YES];

edit summing op, the problem is that you don’t have a navigation controller, so you can’t push a view controller like that. What you can do, is pushing a view controller modally, using

[self presentModalViewController:pdvController animated:YES];