I am using one navigation controller in my application. I am having one main view (with main view controller) and few options views. Options views are viewed by navigation controller when a button clicked on main view's toolbar.
Everything works as expected for first time. When I came back to main view from navigation controller and tries again to go to option view (i.e. navigation controller) my application crashes.
Following is my code,
//Jump to navigation controller from main view controller
optionsViewController *optionsView = [[optionsViewController alloc] initWithNibName:#"optionsView" bundle:nil];
navControllerSettings = [[UINavigationController alloc] initWithRootViewController:(UIViewController *) optionsView];
[self presentModalViewController:self.navControllerSettings animated:YES];
//Code to go back to main view from navigation controller
[self.navigationController dismissModalViewControllerAnimated:YES];
What is correct mechanism to handle navigation controller? Do I need to release/dealloc the navigation controller or options view?
Sample code will help better.
Your navigation controller only gets set up once, then you push and pop other views from its stack.
UINavigationController *navController = [[UINavigationController alloc] init];
UIViewController *yourMainViewController = [[yourMainViewControllerClass alloc] init];
// when you are ready to go to your options view
optionsViewController *optionsView = [[optionsViewController alloc] initWithNibName:#"optionsView" bundle:nil];
[navController pushViewController:optionsViewController animated:YES];
// the back button and the pop from the stack when it is hit is handled auto-magically for you
Thanks for the reply.
But my application architecture is, I am having one main view on which I display few things and having toolbar. Toolbar contains one button, after clicked on that this navigation controller gets created and displayed on the screen.
using back button I came on the main view. But then after I could not go on the navigation again as it is crashing while executing following line
[self presentModalViewController:self.navControllerSettings animated:YES];
What might be the problem here?
Vishal N
I had a similar problem to this with it crashing in presentModalViewController: on second attempt. The problem was caused by calling [self becomeFirstResponder] in viewDidAppear: inside the first UIViewController that I presented, but I failed to call [self resignFirstResponder] in viewWillDisappear:.
Related
On iOS 5, when I try to present any view controller from another one, using presentModalViewController, the modal view is presented behind the current view.
Since it works fine on iOS 4 and knowing that presentModalViewController has been deprecated in iOS 5, I tried using presentViewController with no luck.
This is the first time I encounter this issue, any ideas on what could lead to this weird behavior?
I believe the issue is that you have not set a proper modal presentation style.
http://developer.apple.com/library/ios/documentation/uikit/reference/UIViewController_Class/Reference/Reference.html#//apple_ref/doc/c_ref/UIModalPresentationStyle
This sample should trigger a full screen modal over top of your existing view controller.
[self setModalPresentationStyle:UIModalPresentationFullScreen];
ViewController2 *vc = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
[self presentViewController:vc animated:YES completion:NULL];
Not sure if you're using a button to present the view controller, but this should work if you are. Create a new function in your view controller like the one below. This instantiates your view and a navigation controller in your view so it can be dismissed afterwards.
- (void)buttonPressed {
UIViewController *yourViewController = [[UIViewController alloc] initWithNibName:nil bundle:nil];
UINavigationController *navigationController = [[UINavigationController] alloc] initWithRootViewController:yourViewController];
[self presentModalViewController:navigationController animated:YES];
}
And then in viewDidLoad you'd have something like this (if you were presenting it from a button). The code below is for a UIBarButtonItem, but other buttons should work in a similar manner. Just make sure you set the action parameter to #selector(buttonPressed), or whatever the name of the function you want called when the button is pressed.
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] init]
target:self
action:#selector(buttonPressed)];
I have finally found the issue. For some awkward reasons, the rootViewController of the root window wasn't set properly, leading to strange behaviors with modal views.
What is the more puzzling is that it worked fine on iOS 4 so far and failed on iOS 5. I believe I'm still missing the true reasons leading to such trouble, but correctly setting the rootViewController in AppDelegate solved the problem.
I need to go to the first view in my app. I have a few views pushed onto the stack then a modal navigation controller and more views pushed onto that.
The problem I'm having is that using [[self navigationController] popToRootViewControllerAnimated:YES]; only goes back to the first view in the modal stack.
And I can't get [[self navigationController] popToViewController:.. to work because the true first view controller isn't accesible with [[self navigationController] viewControllers].
Any ideas on how to accomplish this? Thanks.
Do this:
[[self navigationController] dismissModalViewControllerAnimated:YES];
That will get you back to the VC that modally presented the navigation controller. Getting farther back after that depend on how you pushed those "few views" before the navigation controller.
Edit - explanation to get to the deepest root...
It sounds like those "few views" are on another, underlying navigation controller's stack. This can be a little tricky, because the clean way to get farther back in that stack is to have that underlying navigation controller pop to it's own root. But how can it know that the modal VC on top of it is done?
Let's call the view controller that did the modal presentation of second navigation controller VC_a. It's a modally presented navigation controller whose topmost VC is VC_b. How can VC_a know to pop to it's navigation root when VC_b modally dismisses itself?
The good answer (usually) is that VC_b decided to dismiss itself for a reason - some condition in your app/model changed to make it decide to be done.
We want VC_a to detect this condition, too. When VC_b gets dismissed, and VC_a gets a viewWillAppear message because it's about to be uncovered:
// VC_a.m
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
if (/* some app condition that's true when VC_b is done */) {
// I must be appearing because VC_b is done, and I'm being uncovered
// That means I'm done, too. So pop...
[self.navigationController popToRootViewControllerAnimated:NO];
} else {
// I must be appearing for the normal reason, because I was just pushed onto the stack
}
}
You need to do it by using the delegation pattern. Specifically, by creating a protocol that implements the delegate's respondsToSelector method.
See this post for complete details. It should be almost exactly what you are looking for. I had to do something similar, except I only needed to pop one view off the navigation stack instead of using popToRootViewControllerAnimated:.
For iOS6...
[self.view.window.rootViewController dismissViewControllerAnimated:YES completion:nil];
In AppDelegate.m class create method with bellow flow...
-(void)MethodName{//your method name
YourViewController *objViewController = [[[YourViewController alloc] initWithNibName:#"YourViewController" bundle:nil] autorelease]; ///define your viewcontroller name like "FirstViewController"
UINavigationController *yourNavigationController = [[[UINavigationController alloc] initWithRootViewController:objViewController] autorelease];
self.window.rootViewController = yourNavigationController;
}
When you want redirect on firstview just call this method from appdelegate object....
First, I would like to warn that I am a complete newbie into iPhone coding...
I need to show up a viewcontroller from a library, I know that it is modal. I have a tab bar app (created with the default XCode template). I need to show that viewcontroller, there are no problem if it hides the tabbar itself... But I am quite clueless, I don't know even what to search, or what to read...
You can call presentModalViewController:animated: to display another UIViewController modally.
EDIT: If you want to display your modal view in response to a button touch (for example), you would display it like this:
- (IBAction)buttonTouched:(id)sender
{
ModalViewController* controller = [[ModalViewController alloc] init];
[self presentModalViewController:controller animated:YES];
[controller release];
}
Then when you want to dismiss the modal controller, call dismissModalViewControllerAnimated:. This can be called either on your main view controller, or the modal one.
I don't know even what to search, or
what to read...
View Controller Programming Guide is a good place to start to help you understand view controllers (including modal ones). If that's confusing, get a bigger picture with iOS Application Programming Guide or start at the very beginning.
You can call modal view as
YourViewController *yvc = [[YourViewController alloc] initWithNibName:#"YourViewController" bundle:YES]
[self presentModalViewController:yvc animated:YES];
You can call it in the IBAction method in case you want to call it on any control event like Button Click
-(IBAction)buttonClicked:(id)sender
{
YourViewController *yvc = [[YourViewController alloc] initWithNibName:#"YourViewController" bundle:YES]
[self presentModalViewController:yvc animated:YES];
}
You can call it using self.
Hope this helps you.
If you have more doubts on this then you can ask me.
I have an app that has a UITabBarController, one of the tabs of which is configured for a navigation controller.
Based on certain logic I need to attach a different root view to the navigation controller inside the tab at application launch time.
This is easily done in interface builder however, because I need to figure out what view to attach at launch time interface builder is not much use to me in this situation.
I'm guessing I will need to perform this in the applicationDidFinishLaunching method in my app delegate class by somehow getting the tab I'm interested in, and pushing the view onto it's navigation controller?
How would I go about this?
Thanks.
You're on the right track. In your app delegate's applicationDidFinishLaunching method, you need to look at whatever your condition is and pick the right thing to set as the UINavigationController's root view controller.
I'm guessing this is a login screen or something? And if you have a cached login from an earlier session you don't show it again? Is that it?
If you take a look at that method in your application delegate, you'll see where the default root view controller is getting instantiated and pushed into the nav controller. Just duplicate that code inside an if() statement. I've done this, it's straightforward.
So what I did in my applicationDidFinishLaunching method was:
// get the array of tabs
NSArray *tabBarArray = tabBarController.viewControllers;
// in my case the navigation controller I'm interested in is in the 4th tab
UINavigationController *navigationController = [tabBarArray objectAtIndex:4];
if(someLogic == true) {
ViewController1 *viewController1 = [[viewController1 alloc] initWithNibName:#"View1" bundle:nil];
[navigationController pushViewController:viewController1 animated:NO];
[viewController1 release];
}
else {
ViewController2 *viewController2 = [[viewController2 alloc] initWithNibName:#"View2" bundle:nil];
[navigationController pushViewController:viewController2 animated:NO];
[viewController2 release];
}
Everything working well.
I am creating a navigation based application. I have different views which are pushed and poped from navigation controller (pop is mainly using back button). Here is the code that I am using for pushing view controller.
MyViewController *dvController = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:nil];
[self.navigationController pushViewController:dvController animated:YES];
[dvController release];
I would like the to set delay in animation when new view controller is pushed. Default slide animation in iphone is ok for me. But with some delay.
Is there any way to do this?
Can use NsTimer to set the required delay.and call the method using timer.
Wrap the above code in a method and call it with -performSelector:afterDelay:.