I am trying to do like this, with the commented lines it works good, without, when I came back from the "pushed" view my App just crashes... when should I [release]? Or, better, I am doing this correctly?
if (indexPath.row == 1) {
Credits *cr = [[Credits alloc] initWithNibName:#"Credits" bundle:nil];
[self.navigationController pushViewController:cr animated:YES];
//[cr release];
}else{
Search *sr = [[Search alloc] initWithNibName:#"Search" bundle:nil];
[self.navigationController pushViewController:sr animated:YES];
//[sr release];
}
You should release your controller after pushing it onto the navigation view controller's stack of controllers. My guess is that something else is going on in the dealloc of your Search and Credits objects, that you are overreleasing an object there.
Related
I am pushing an object on navigation controller but when I return the control from the that view controller it crashes the app.
[self.navigationController pushViewController:chequeDetails animated:YES];
[chequeDetails release];
but when I write the same code with
[self.navigationController pushViewController:chequeDetails animated:YES];
chequeDetails=nil;
[chequeDetails release];
The app does not crash but a slight lag is observed... when i pop back from the check details controller?
If your seconds exaple code, you are not release the chequeDetails since calling release on a nil object does not nothing:
[self.navigationController pushViewController:chequeDetails animated:YES];
chequeDetails=nil;
// calling the release on nill will do nothing
[chequeDetails release];
Normally you can do it this ways:
[self.navigationController pushViewController:chequeDetails animated:YES];
[chequeDetails release], chequeDetails = nil;
But only release the chequeDetails if you did a alloc, init like:
ChequeDetails *chequeDetails = [[ChequeDetails alloc] initWithNibName:#"ChequeDetails" bundle:nil];
So the full code should be something like:
ChequeDetails *chequeDetails = [[ChequeDetails alloc] initWithNibName:#"ChequeDetails" bundle:nil];
[self.navigationController pushViewController:chequeDetails animated:YES];
[chequeDetails release], chequeDetails = nil;
I dont Know Exat... but i think you need to create a object of your delegate and you need to write appDelegate.navigationController rather then self.navigationController...
Note: appDelegate is a object of Delegate.
I'm doing an application which uses a UINavigationController and I'm switching to other UIViewControllers as follows:
if(self.myViewController == nil){
MyViewController *aViewController = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:nil];
self.myViewController = aViewController;
[aViewController release];
}
AppDelegate *delegate = [[UIApplication sharedApplication] delegate];
[delegate.myNavController pushViewController:myViewController animated:YES];
I imagine this is creating a pile of UIViewControllers into the UINavigationController, maybe an array of indexs? I would like to know how to turn back without having to be back one by one.
For example, I'm sailing through a few screens and with a button I would like to return at the first index of navigation. I would also like know how to modify indexes, view, erase and anything pertaining to this issue.
Sorry if I have not explained well.
You've asked two questions.
The first is, how do I get back to my first view controller. As #Thomas Clayson and #ender have answered, you want the popToRootViewControllerAnimated: method of your navigationcontroller object for that.
The second is how to move to a particular index in the view controller stack. The answer to that is, you can set the array of viewControllers explicitly. So you can pull out the current listing of view controllers, modify it, and set it back into the navigationController stack. It'll reset the stack and animate you moving to the top item in the stack.
Thusly:
NSMutableArray *controllers = self.navigationController.viewControllers;
[controllers removeObjectAtIndex:[controllers count] - 1]; //or whatever
[self.navigationController setViewControllers:controllers animated:YES];
NSArray *viewControllers = [[self navigationController] viewControllers];
for (int i = 0; i < [viewContrlls count]; i++){
id obj = [viewControllers objectAtIndex:i];
if ([obj isKindOfClass:[yourViewControllername class]]){
[[self navigationController] popToViewController:obj animated:YES];
return;
}
}
Using this you can come back to any specified viewController.
[self.navigationController popToRootViewControllerAnimated:YES];
Will take you back to the very first view controller (root view controller).
Hope this helps
Use this
NSArray *viewContrlls=[[NSArray alloc] initWithArray:[[self navigationController] viewControllers]];
id obj=[viewContrlls objectAtIndex:1];
[[self navigationController] popToViewController:obj animated:YES];
[viewContrlls release];
You should use popToRootViewControllerAnimated: From UINavigationController class reference:
Pops all the view controllers on the stack except the root view
controller and updates the display.
You can return to the first view with
[self.navigationController popToRootViewControllerAnimated:YES];
That being said, you can also remove a particular view controller, or navigate to a specific index in your view controller if you look at the example.
NSMutableArray *allViewControllers = [NSMutableArray arrayWithArray:navigationController.viewControllers];
// You can now manipulate this array with the methods used for NSMutableArray to find out / perform actions on the navigation stack
[allViewControllers removeObjectIdenticalTo: removedViewController];
// You can remove a specific view controller with this.
navigationController.viewControllers = allViewControllers;
When I push cancel button in the third view, I want to go back to the first view directly.
I also want to remove the second view.
How can I do that?
This is the code.
// this part is in the first view.
self.second = [SecondController alloc] init];
[self.view addSubview:second.view];
// this part is in the second view.
ThirdController *thirdController = [[ThirdController alloc] initWithStyle:UITableViewStyleGrouped];
self.navigationController = [UINavigationController alloc] initWithRootViewController:thirdController];
[self.view addSubview:navigationController.view];
// this part is in the third view.
- (void)cancel {
[self.view removeFromSuperview]; // this only goes to the second view.
}
EDIT:
Can I use popToViewController in called contoller? My app crashes.
I thought popToViewController can be used only in calling controller.
And popToViewController is used when it was pushed.
I did add not push.
[self.navigationController popToViewController:[[self.navigationController viewControllers] objectAtIndex:0] animated:YES];
popToViewController:animated: is a UINavigationController method that you use when popping view controllers off the navigation controller stack. It doesn't fit for this scenario.
This user is adding subviews, not pushing them on a navigation controller stack.
As a note, it appears as a matter of design you should be using a navigation controller with the first view as the root controller, then the second pushed on the stack, and the third pushed on the stack. Then all you have to do is [self.navigationController popToRootViewControllerAnimated:YES].
I think this will work if you want to keep your current architecture:
// this part is in the third view.
- (void)cancel {
// remove the second view (self.view.superview) from the first view
[self.view.superview removeFromSuperView];
// can't recall, possibly you still need to remove the third view, but i think removing the superview will do it.
// [self.view removeFromSuperView];
}
If you prefer to try the UINavigationController route, then the easiest path is to create a new project in Xcode and select the type for a Navigation-Based Application or a Master-Detail Application. This will create a UINavigationController in a nib and add it to your window. You can then set the root view controller in Interface Builder to your FirstViewController class.
If you prefer to create the UINavigationController in code, then that is also possible. I show that below, along with the rest of the code you need, regardless of whether you create your UINavigationController in a nib in IB or in code.
I also recommend reading the View Controller Programming Guide for iOS.
In your app delegate or some other code:
-(void)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions [
// I would recommend setting up the UINavigationController and FirstViewController as IBOutlets in your nib, but it can be done in code.
FirstViewController* fvc = [[FirstViewController alloc] initWithNibName:#"FirstView" bundle:nil];
UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:fvc];
[window addSubView:navController.view];
[window makeKeyAndVisible];
[fvc release];
[navController release];
}
In the first view controller:
SecondViewController* svc = [[SecondViewController alloc] initWithNibName:#"SecondView" bundle:nil];
[self.navigationController pushViewController:svc animated:YES];
[svc release];
In the second view controller:
ThirdViewController* tvc = [[ThirdViewController alloc] initWithNibName:#"ThirdView" bundle:nil];
[self.navigationController pushViewController:tvc animated:YES];
[tvc release];
In the third view controller:
-(void)cancel {
// returns to the first view controller
[self.navigationController popToRootViewControllerAnimated:YES];
}
Use
- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated
to go back to a specific view controller.
Try this:
[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1] animated:YES];
This will pop to the view at index 1. Hope that Helps!
// this part is in the third view.
- (void)cancel {
self.first = [SecondController alloc] init];
[self.view addSubview:second.view];
}
And I think if you have you don't need to be worried about removing beneath view, later these will removed.
I am having problems with getting a detail view to load using pushViewController. At first, I thought pushViewController was not working. BUT, then I tried using a different view controller and it worked. I can tell from tracing that the problem view controller is never loaded at all. In other words, I tried to eliminate the possibility that there was some error in the view controller by NSLoging in that object and I never see anything.
Does anyone have any ideas?
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
/*
NSLog(#"hsitkjsdfkljlkd");
if (childController == nil)
childController = [[salesViewController alloc] initWithNibName:#"salesView" bundle:nil];
//NSUInteger row = [indexPath row];
[self.navigationController pushViewController:childController
animated:YES];
*/
/*
//modal = blocking
salesViewController *otherVC = [[salesViewController alloc] initWithNibName:#"salesView" bundle:nil];
//must set sale type
otherVC.strSaleType = #"Voice";
[self presentModalViewController: otherVC animated:YES];
//No close. By design, it is up to the otherVC to close itself
*/
//tipCalcViewController *detailViewController = [[tipCalcViewController alloc] initWithNibName:#"tipCalcView" bundle:nil];
salesViewController *detailViewController = [[salesViewController alloc] initWithNibName:#"salesView" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
Just Check the
- (void)viewWillAppear:(BOOL)animated
{
}
of the salesViewController.
you are doing something wrong in this..
put the debugging point in the viewWillAppear and run it. you can get the error line..
just try it......Surely it will work for u...
salesViewController *detailViewController = [[salesViewController alloc] initWithNibName:#"salesViewController" bundle:nil];
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
Also make sure you are giving the IBOutlet connection to UIView.
In my case I had several IBOutlets that I removed from the Header file and forgot to remove the connection to these non-existing outlets in Interface Builder. So removing the obsolete outlets fixed the problem in my case.
When you're pushing from ViewController1 to ViewController2 then the code will be used like this so try this code,
ViewController2 *vw2=[[ViewController2 alloc]initWithNibName:#"ViewController2" bundle:nil];
[self.navigationController pushViewController:vw2 animated:YES];
The Above code may be written on Click event of button or on didSelect delegate of UITableView
I have an application where I need to remove one view from the stack of a UINavigationController and replace it with another. The situation is that the first view creates an editable item and then replaces itself with an editor for the item. When I do the obvious solution within the first view:
MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];
[self retain];
[self.navigationController popViewControllerAnimated: NO];
[self.navigationController pushViewController: mevc animated: YES];
[self release];
I get very strange behavior. Usually the editor view will appear, but if I try to use the back button on the nav bar I get extra screens, some blank, and some just screwed up. The title becomes random too. It is like the nav stack is completely hosed.
What would be a better approach to this problem?
Thanks,
Matt
I've discovered you don't need to manually mess with the viewControllers property at all. Basically there are 2 tricky things about this.
self.navigationController will return nil if self is not currently on the navigation controller's stack. So save it to a local variable before you lose access to it.
You must retain (and properly release) self or the object who owns the method you are in will be deallocated, causing strangeness.
Once you do that prep, then just pop and push as normal. This code will instantly replace the top controller with another.
// locally store the navigation controller since
// self.navigationController will be nil once we are popped
UINavigationController *navController = self.navigationController;
// retain ourselves so that the controller will still exist once it's popped off
[[self retain] autorelease];
// Pop this controller and replace with another
[navController popViewControllerAnimated:NO];
[navController pushViewController:someViewController animated:NO];
In that last line if you change the animated to YES, then the new screen will actually animate in and the controller you just popped will animate out. Looks pretty nice!
The following approach seems nicer to me, and also works well with ARC:
UIViewController *newVC = [[UIViewController alloc] init];
// Replace the current view controller
NSMutableArray *viewControllers = [NSMutableArray arrayWithArray:[[self navigationController] viewControllers]];
[viewControllers removeLastObject];
[viewControllers addObject:newVC];
[[self navigationController] setViewControllers:viewControllers animated:YES];
From experience, you're going to have to fiddle with the UINavigationController's viewControllers property directly. Something like this should work:
MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];
[[self retain] autorelease];
NSMutableArray *controllers = [[self.navigationController.viewControllers mutableCopy] autorelease];
[controllers removeLastObject];
self.navigationController.viewControllers = controllers;
[self.navigationController pushViewController:mevc animated: YES];
Note: I changed the retain/release to a retain/autorelease as that's just generally more robust - if an exception occurs between the retain/release you'll leak self, but autorelease takes care of that.
After much effort (and tweaking the code from Kevin), I finally figured out how to do this in the view controller that is being popped from the stack. The problem that I was having was that self.navigationController was returning nil after I removed the last object from the controllers array. I think it was due to this line in the documentation for
UIViewController on the instance method navigationController
"Only returns a navigation controller if the view controller is in its stack."
I think that once the current view controller is removed from the stack, its navigationController method will return nil.
Here is the adjusted code that works:
UINavigationController *navController = self.navigationController;
MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];
NSMutableArray *controllers = [[self.navigationController.viewControllers mutableCopy] autorelease];
[controllers removeLastObject];
navController.viewControllers = controllers;
[navController pushViewController:mevc animated: YES];
Thanks, this was exactly what I needed. I also put this in an animation to get the page curl:
MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];
UINavigationController *navController = self.navigationController;
[[self retain] autorelease];
[UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration: 0.7];
[UIView setAnimationTransition:<#UIViewAnimationTransitionCurlDown#> forView:navController.view cache:NO];
[navController popViewControllerAnimated:NO];
[navController pushViewController:mevc animated:NO];
[UIView commitAnimations];
0.6 duration is fast, good for 3GS and newer, 0.8 is still a bit too fast for 3G..
Johan
If you want to show any other view controller by popToRootViewController then you need to do following:
UIViewController *newVC = [[WelcomeScreenVC alloc] initWithNibName:#"WelcomeScreenVC" bundle:[NSBundle mainBundle]];
NSMutableArray *viewControllers = [NSMutableArray arrayWithArray:[[self navigationController] viewControllers]];
[viewControllers removeAllObjects];
[viewControllers addObject:newVC];
[[self navigationController] setViewControllers:viewControllers animated:NO];
Now, all your previous stack will be removed and new stack will be created with your required rootViewController.
I had to do a similar thing recently and based my solution on Michaels answer. In my case I had to remove two View Controllers from the Navigation Stack and then add a new View Controller on. Calling [controllers removeLastObject]; twice, worked fine in my case.
UINavigationController *navController = self.navigationController;
// retain ourselves so that the controller will still exist once it's popped off
[[self retain] autorelease];
searchViewController = [[SearchViewController alloc] init];
NSMutableArray *controllers = [[self.navigationController.viewControllers mutableCopy] autorelease];
[controllers removeLastObject];
// In my case I want to go up two, then push one..
[controllers removeLastObject];
navController.viewControllers = controllers;
NSLog(#"controllers: %#",controllers);
controllers = nil;
[navController pushViewController:searchViewController animated: NO];
This UINavigationController instance method might work...
Pops view controllers until the specified view controller is the top view controller and then updates the display.
- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated
Here is another approach that doesn't require directly messing with the viewControllers array. Check if the controller has been pop'd yet, if so push it.
TasksViewController *taskViewController = [[TasksViewController alloc] initWithNibName:nil bundle:nil];
if ([navigationController.viewControllers indexOfObject:taskViewController] == NSNotFound)
{
[navigationController pushViewController:taskViewController animated:animated];
}
else
{
[navigationController popToViewController:taskViewController animated:animated];
}
NSMutableArray *controllers = [self.navigationController.viewControllers mutableCopy];
for(int i=0;i<controllers.count;i++){
[controllers removeLastObject];
}
self.navigationController.viewControllers = controllers;
My favorite way to do it is with a category on UINavigationController. The following should work:
UINavigationController+Helpers.h
#import
#interface UINavigationController (Helpers)
- (UIViewController*) replaceTopViewControllerWithViewController: (UIViewController*) controller;
#end
UINavigationController+Helpers.m
#import "UINavigationController+Helpers.h"
#implementation UINavigationController (Helpers)
- (UIViewController*) replaceTopViewControllerWithViewController: (UIViewController*) controller {
UIViewController* topController = self.viewControllers.lastObject;
[[topController retain] autorelease];
UIViewController* poppedViewController = [self popViewControllerAnimated:NO];
[self pushViewController:controller animated:NO];
return poppedViewController;
}
#end
Then from your view controller, you can replace the top view with a new by like this:
[self.navigationController replaceTopViewControllerWithViewController: newController];
You can check with navigation view controllers array which you give you all view controllers that you have added in navigation stack. By using that array you can back navigate to specific view controller.
For monotouch / xamarin IOS:
inside UISplitViewController class;
UINavigationController mainNav = this._navController;
//List<UIViewController> controllers = mainNav.ViewControllers.ToList();
mainNav.ViewControllers = new UIViewController[] { };
mainNav.PushViewController(detail, true);//to have the animation
Alternatively,
You can use category to avoid self.navigationController to be nil after popViewControllerAnimated
just pop and push, it's easy to understand, don't need to access viewControllers....
// UINavigationController+Helper.h
#interface UINavigationController (Helper)
- (UIViewController*) popThenPushViewController:(UIViewController *)viewController animated:(BOOL)animated;
#end
// UINavigationController+Helper.m
#implementation UINavigationController (Helper)
- (UIViewController*) popThenPushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
UIViewController *v =[self popViewControllerAnimated:NO];
[self pushViewController:viewController animated:animated];
return v;
}
#end
In your ViewController
// #import "UINavigationController+Helper.h"
// invoke in your code
UIViewController *v= [[MyNewViewController alloc] init];
[self.navigationController popThenPushViewController:v animated:YES];
RELEASE_SAFELY(v);
Not exactly the answer but might be of help in some scenarios (mine for example):
If you need to pop viewcontroller C and go to B (out of stack) instead of A (the one bellow C), it's possible to push B before C, and have all 3 on the stack. By keeping the B push invisible, and by choosing whether to pop only C or C and B altogether, you can achieve the same effect.
initial problem
A -> C (I want to pop C and show B, out of stack)
possible solution
A -> B (pushed invisible) -> C (when I pop C, I choose to show B or also pop it)
I use this solution to keep the animation.
[self.navigationController pushViewController:controller animated:YES];
NSMutableArray *newControllers = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];
[newControllers removeObject:newControllers[newControllers.count - 2]];
[self.navigationController setViewControllers:newControllers];