I have a problem where I can successfully push a new view controller from my root view controller (using the Navigation-based application using Core Data template), but the detail view, which is a separate xib file from the root view controller, doesn't display the back navigation button. I'm certain that I've done all of the proper connections in IB, and everything else is working as expected.
RootViewController.h
#class ItemsViewController;
#interface RootViewController : UITableViewController <NSFetchedResultsControllerDelegate> {
IBOutlet ItemsViewController *itemsVC;
}
#property (nonatomic, retain) IBOutlet ItemsViewController *itemsVC;
#end
RootViewController.m
#import "ItemsViewController.h"
#synthesize itemsVC;
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Pushes to ItemsViewController
ItemsViewController *itemsViewController = [[ItemsViewController alloc] initWithNibName:#"ItemsViewController" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:itemsViewController animated:YES];
[itemsViewController release];
}
ItemsViewController is a UITableViewController subclass with its own xib, also named ItemsViewController. Again, it gets pushed from RootViewController, but the back button doesn't show up like this. I was under the impression that it was a "free" feature of using a navigation controller. As you might expect, this is a very frustrating roadblock and I would appreciate any help.
Does your ItemsViewController class set its title property in its viewDidLoad method?
You should call [tableView deselectRowAtIndexPath:indexPath animated:YES] as the last line of tableView:didSelectRowAtIndexPath: to conform to Apple's human interface guidelines.
Yeah, make sure you have a title on your RootViewController, if it doesn't no button will appear. To set a title programmatically;
self.navigationItem.title = #"Hello Der";
Some extra info for future readers: I ran into this problem while trying to re-populate a nav hierarchy on application load, so I was calling setViewControllers: from the app delegate's application:didFinishLaunchingWithOptions: method. And I was running into the same problem with the back button not showing up.
In my case, setting the root view controller's nav item title in its viewDidLoad did not work, presumably because the other views were loading first and seeing the root's title as null. Instead, I set the root view controller's nav item title in my application:didFinishLaunchingWithOptions: method right before I called setViewControllers:, and that fixed it.
This can also happen if you're a bonehead and mistakenly initialize the view as modal instead of pushing a view to the navigation controller.
oops: [self presentModalViewController:navController animated:YES];
meant: [self.navigationController pushViewController:controller animated:YES];
Try following snippet. It work for me!
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:#"Image.png"] forBarMetrics:UIBarMetricsDefault];
[self.navigationController.navigationBar bringSubviewToFront:[self.navigationController.navigationItem backBarButtonItem]];
Related
Bit confused with this one so bear with me...
I have a Navigation-based project which is working fine. I'm trying to create my first custom UIView to make a couple of buttons which I will use in multiple places. One of the buttons needs to push a viewcontroller into the navigation when it's clicked but I'm not sure how to do this.
When I had the button set up within a view controller I was using:
LocationViewController *controller = [[LocationViewController alloc] initWithNibName:#"LocationViewController" bundle:nil];
[self.navigationController pushViewController:controller animated:YES];
[controller release];
but the self.navigation controller won't work now, will it? How do I access the navigation controller of the viewcontroller that this uiview will be added to?
Hope at least some of that makes sense, as I said it's my first go at subclassing the uiview and adding it to multiple pages so I'm a bit lost.
EDIT TO ADD - I have the button click events inside the custom UIView, so that is where I'm trying to change the viewcontroller from. Should I instead wire up the events in whichever viewcontroller I add the view to?
Usually your appDelegate has a UINavigationController property. You can access it in your custom view like this:
UINavigationController *navController = (MyAppDelegate *)[[[UIApplication sharedApplication]
delegate] navigationController];
But more effective way is to make delegate method for your custom view and handle button action in your viewController.
MyCustomView.h
#protocol MyCustomViewDelegate
#interface MyCustomView : UIView {
id<MyCustomViewDelegate> cvDelegate; }
#property(nonatomic, assign) id<MyCustomViewDelegate> cvDelegate;
#protocol MyCustomViewDelegate #optional
-(void)didClickInCustomView:(MyCustomViewDelegate*)view withData:(NSObject*)data;
#end
MyCustomView.m
- (void)myButtonClick:(id)sender
{
[self.cvDelegate didClickInCustomView:self withData:someData];
}
So now you can handle this event in any place where is your custom
view.
Add the button from the interface builder or from the view controller's viewDidLoad using code:
CGRect frame = CGRectMake(0, 0, 24, 24);
UIButton *button = [[UIButton alloc] initWithFrame:frame];
[button addTarget:self action:#selector(handleMyButton:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
Then implement -(void)handleMyButton:(id)sender {}; in your view controller. Or you could instead write -(IBAction)handleMyButton:(id)sender {}; and link method and button using the interface builder.
Then inside the method just paste the block of code you posted above. If you started with the Xcode navigation controller template project it should work.
I think it's cleaner to hide the designated initializer initWithNibName: because it is an implementation detail.
When you say you are subclassing the UIView I don't know exactly what you mean. If you want to add another view controller with a custom view just use the UIViewController template and customize the XIB file, no need to subclass an UIView unless you are really modifying its behaviour, which I guess you are not. The view is a view, and the controller stuff like handling buttons should be in the controller.
The actual controller need to be in the navigation controller stack to be able to push another controller.
Or you can make a new navigation controller instance and push your LocationViewController.
I have a view that shows a map. I have a custom subclass of UIViewController (DetailViewController) that gets shown when the detailDisclosureButton of the callout above the pin is pressed. While in my map class, I create my detailview and add it to the subview like this:
DetailViewController *detailView = [[DetailViewController alloc] initWithNibName:#"DetailView" bundle:nil];
detailView.locationPoint = locationPoint;
detailView.locationCoordinate = locationCoordinate;
[self.view addSubview:detailView.view];
[detailView release];
My DetailViewController has a TableView and parses the data in DetailViewController. However I get an error of sending the numberOfSectionsInTable message to a dealloc'd instance. I'm assuming it is this since I originally had this as a property and it worked fine with (nonatomic, retain). I'm assuming that I'm releasing it before the next view is done with it. If that is the case, when would I clean up the memory??? It seems like this would be the place to do it. Thanks.
I am not sure what makes you adding the view of DetailViewController into this mapviewcontroller's view. Don't you think right approach would be to either presentModalViewController or pushNavigationController?
DetailViewController *detailView = [[DetailViewController alloc] initWithNibName:#"DetailView" bundle:nil];
detailView.locationPoint = locationPoint;
detailView.locationCoordinate = locationCoordinate;
//[self.view addSubview:detailView.view];
[self.navigationController pushViewController:detailView animated:YES];
//OR
[self presentModalViewController:detailView animated:YES];
[detailView release];
You are getting the error because you are only using the view and deallocating the view controller immediately and hence tableview datasource and delegates are hitting a nil object.
Views do not retain their view controllers. Someone needs to retain the VC or else it will get released, and then the app will crash when the view makes a call into its delegate. When you use a navigation controller, the navcon has a stack of view controllers that it retains. Likewise with presentModalViewController, the OS takes care of retaining the detail VC.
Adding a detail view as a subview is not the normal way to navigate to a new view. Instead, one either uses a navigation controller and [navcon pushViewController::], or a modal subview and [self presentModalViewController::]. If the detail view occupies only a portion of the parent view, then it is normal to retain the view controller for the subview within the parent controller. That is, within the parent VC (your map class) add a property for the detail VC. Actually, it's more common to not even use a VC for a subview, but rather for screen-filling detail views.
I created a view in IB with a navbar and a table. On the navbar I put two buttons, cancel and done. I use this view like a modal view with:
[self presentModalViewController:controller animated:YES];
My problem is when I use:
[self.navigationItem.rightBarButtonItem setEnabled:YES];
to enable the right button. It doesn't work.
Have I to set a delegate? what code passages I have to do? It works if I create an IBOutlet for the right button and I use [doneButton setEnabled:YES], but I think this isn't the proper way.
In order to place a navigation bar on your modal view controller in interface builder (and set up bar button items that call actions in your detail view controller), you need to go through a level of indirection (your navigation bar will be in one .xib, and the details of your detail view will be in a different xib):
create a xib file containing a navigation controller object, and set its root view controller to be your detail view controller that you want to display modally with a navigation bar.
add bar button items to the detail controller's navigation bar and hook them up to IBActions in your detail view controller object.
your detail view controller will need to be in a separate .xib file
create a "loader" object that just exists to hold the navigation controller iboutlet, and set it to be the File's Owner object of that xib:
#interface Loader : NSObject
#property (nonatomic, retain) IBOutlet UINavigationController *navVC;
#end
#implementation Loader
#synthesize navVC;
- (void) dealloc
{
[navVC release];
[super dealloc];
}
#end
Your xib file containing the navigation controller will look like this:
Make sure the navigation controller object is conntected to the "Loader" object's navVC outlet, and make sure the bar button items are connected to your detail view controller's desired IBActions.
Then you present this whole thing using this code:
Loader *loader = [[[Loader alloc] init] autorelease];
[[NSBundle mainBundle] loadNibNamed:#"ModalVC" owner:loader options:nil];
[self presentModalViewController:loader.navVC animated:YES];
Delegate has nothing to do with your issue.
You probably did put navigation bar into your view directly. Thus things like self.navigationItem doesn't work. You have two choices ...
Connect your buttons to outlets in your code and access them directly.
Or remove navigation bar from your view and present your view controller in this way ...
MyViewController *vc = [[MyViewController alloc] initWith...];
UINavigationController *navCon = [[UINavigationController alloc] initWithRootViewController:vc];
[vc release];
[self presentModalViewController:navCon animated:YES];
[navCon release];
... and now you can access left/right buttons via navigationItem.
I need to pop up a quick dialog for the user to select one option in a UITableView from a list of roughly 2-5 items. Dialog will be modal and only take up about 1/2 of screen. I go back and forth between how to handle this. Should I subclass UIView and make it a UITableViewDelegate & DataSource?
I'd also prefer to lay out this view in IB. So to display I'd do something like this from my view controller (assume I have a property in my view controller for DialogView *myDialog;)
NSArray* nibViews = [[NSBundle mainBundle] loadNibNamed:#"DialogView" owner:myDialog options:nil];
myDialog = [nibViews objectAtIndex:0];
[self.view addSubview:myDialog];
problem is i'm trying to pass owner:myDialog which is nil as it hasn't been instantiated...i could pass owner:self but that would make my view controller the File's Owner and that's not how that dialog view is wired in IB.
So that leads me to think this dialog wants to be another full blown UIViewController... But, from all I've read you should only have ONE UIViewController per screen so this confuses me because I could benefit from viewDidLoad, etc. that come along with view controllers...
Can someone please straighten this out for me?
There is no such thing as a view controller being on the screen; its view is on the screen. With that said, you can present as many views as you want on the screen at once.
I would create a new view and view controller. You would not make a UIView be a UITableViewDelegate, you make a UIViewController be a UITableViewDelegate. But instead of doing that manually, instead make your new view controller a subclass of UITableViewController, if you're using iPhone OS 3.x+. You can then present this view controller modally.
You probably want to give the user a chance to cancel out of the selection. A good way to do that is to wrap your new dialog view controller in a UINavigationController and then put a "Cancel" button in the nav bar. Then use the delegate pattern to inform the parent view controller that the user has made their choice so you can pop the stack.
Here's what the code will look like inside your parent view controller, when you want to present this option dialog:
- (void)showOptionView
{
OptionViewController* optionViewController = [[OptionViewController alloc] initWithNibName:#"OptionView" bundle:nil];
optionViewController.delegate = self;
UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:optionViewController];
[self.navigationController presentModalViewController:navController animated:YES];
[navController release];
[optionViewController release];
}
Your OptionViewController .h will look like this:
#protocol OptionViewControllerDelegate;
#interface OptionViewController : UITableViewController
{
id<OptionViewControllerDelegate> delegate;
}
#property (nonatomic, assign) id<OptionViewControllerDelegate> delegate;
#end
#protocol OptionViewControllerDelegate <NSObject>
- (void)OptionViewController:(OptionViewController*)OptionViewController didFinishWithSelection:(NSString*)selection;
// or maybe
- (void)OptionViewController:(OptionViewController*)OptionViewController didFinishWithSelection:(NSUInteger)selection;
// etc.
#end
Your OptionViewController.m will have something like this:
- (void)madeSelection:(NSUInteger)selection
{
[delegate OptionViewController:self didFinishWithSelection:selection];
}
Which has a matching method back in your original view controller like:
- (void)OptionViewController:(OptionViewController*)OptionViewController didFinishWithSelection:(NSUInteger)selection
{
// Do something with selection here
[self.navigationController dismissModalViewControllerAnimated:YES];
}
There are plenty of examples throughout Apple's sample source code that follow this general pattern.
here is a iPhone programming beginner's question:
How do I get to another view by pressing a button in my main view?
I have the following function which is executed when I press a button, and debugging it, he passes there, but my "Warning" view does not show up:
-(IBAction) showWarningView:(id)sender
{
if(self.showWarning == nil){
WarningViewController *nextView = [[WarningViewController alloc] initWithNibName:#"Warning" bundle:[NSBundle mainBundle]];
self.showWarning = nextView;
[nextView release];
}
[self.navigationController pushViewController:self.showWarning animated:YES];
}
My main RootViewController looks like this:
#import <UIKit/UIKit.h>
#import "WarningViewController.h"
#interface RootViewController : UIViewController {
IBOutlet UIButton *button1;
WarningViewController *showWarning;
}
#property(nonatomic,retain) WarningViewController *showWarning;
-(IBAction) showWarningView:(id)sender;
#end
I am using the navigation control of a UITableViewController but what do I have to use to just simply show my other view when I press a button in a view-based application?
Thanks a lot!
edited
if you're using the navigation control of a UITableViewController, you probably have to push the view in you tableviewcontrollers navigation controller
this means you have pass the navigation controller of your tableviewcontroller on to your viewcontroller, then you just push it
e.g.
[self.tableViewControllersNavigationController pushViewController:self.showWarning animated:YES];
(for passing the tableViewController's navigationController on, you might have to create a delegate pattern)
Does the title in your navigation bar change? Maybe you don't have a UIView associated with your UIViewController inside your Interface Builder file.