I'm currently programming an app for iphone that uses the tab bar. One of the views it links to uses a navigation controller so that i can drill down the table view that I am using to display info to the user. It all works OK I can drill down the table view no problem, i can push the current table view off the view stack and return back up the stack to the first view using the back button in the navigation bar.
The problem I have is that if I drill down more than 1 view level and press the tab bar button for that view the application exits and Xcode shows a EXC_BAD_ACCESS.
The tab bars button is obviously trying to jump back to the first view in the stack, but should it be doing this?
If so, how do I make the button push everything from the stack or is it possible to disable the tab bar button from that view trying to show the top view again?
Its not really desirable for the whole app to return to the first view if the user accidentally taps the button.
Any help appreciated :)
I had an autorelease set on the view object I was trying to link back to from the tab bar and hadn't noticed that I was also releasing the same object in the dealloc method also. So when I viewed the view the first time I clicked the tab it was still in memory but when coming back to the view its retain count had been set to zero removing it from memory altogether.
Solved it by removing the release cal in the dealloc method. Alternatively removing the autorelease would have done the same thing.
Related
I want to create an app where there is a login screen, and when user logs in open up home page with tab bar controller.
I have created a single view application and have created login screen, home screen and a tab bar on it.
In tab bar delegate, I am adding screens to tab bar by [self.view addSubView firstView.view]
My problem is if I open up 4th tab, and switch to 2nd tab and I have to go back to home screen, so I press home btw on nav bar, it shows view 4 which is already on stack of uiviews.
How do I switch between all tab bar views and add navigation to them ? Which ideal method is to be used?
I've created app that is doing what you need (I guess). You can find it in app store for iphone using name Torchoo. It is free and there is test account so you can see how it works and if its really what you need. If yes, ping me here I will show you the sources and how I did it.
In couple of words, you need normal tabbar controller that has number of navigation controllers and each of them has number of view controllers. And login screen is just a modal view that shows/hides when you need it. Most of things may be done in storyboard.
I don't get it actually but i think you want to attach all the view by navigation controller.
But it's useless. if you want to use navigation bar then it ll navigate in another view but tabbar will give you different views on every tab.
so, first see the use of both of them then ask....
So I have an iPhone app. It has a simple structure, all based on a UINavigationController.
I have a storyboard that has one view, a segue to another view, etc. Now this other view has a UITextView that I do not want to edit on this screen - if the user taps this, I want it instead to fly over to a second screen which basically has the same text view, but this one is full-screen, and the user will edit the text on that screen before returning to the previous screen.
So I capture the textViewShouldBeginEditing method. I previously, in the storyboard editor, manually created a push segue from the previous view controller to this new view controller, and named it so that I can call it by it's identity, which I do with:
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
// This is called when the user clicks into the textView as if to edit it.
// Instead of editing it, go to this other view here:
[self performSegueWithIdentifier:#"editMemoSegue" sender:self];
// Return NO, as I don't actually want to edit the text on this screen:
return NO;
}
Seems reasonable. And it works. Sorta. It does in fact shoot me over to that other view. That other view's events fire up, I set it's text view to become first responder, I edit the text on that screen. Everyone's happy.
Until I want to use the back button to return to the previous view.
Then I quickly find out - my navigation stack is foobared. Most of the time, I have, for some reason, TWO instances of my new editing controller on the stack, so the first time I hit the back button I get the same stuff over again. Then, oddly, occasionally, it will work as intended, and I will see my previous controller with only one back click.
I started reading the log, and I found this:
2012-12-09 09:41:03.463 APP[8368:c07] nested push animation can result in corrupted navigation bar
2012-12-09 09:41:03.818 APP[8368:c07] Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
2012-12-09 09:41:03.819 APP[8368:c07] Unbalanced calls to begin/end appearance transitions for <SecondController: 0x83881d0>.
So obviously, I'm doing something incorrectly here. The question is, what? And how do I do what I want in the way that correctly appeases the tiki gods of the iPhone framework?
Check to see if the textViewShouldBeginEditing is being called twice. I've noticed that these kinds of delegate calls sometimes are.
How is your #"editMemoSegue" being created on the storyboard? is it created from the textView? if it is then you should recreate it directly from the view controller or from the top status bar on the view controller that way it wont be called twice when you touch the trigger object and when you call it programmatically.
I'm writing an iPhone app using Appcelerator Titanium Mobile. I am hiding and showing the tab group based on what window has focus.
dashWin.addEventListener("focus",function(e) {
if (dashWin.tabGroupVisible == true) {
dashWin.tabGroupVisible=false;
tabGroup.animate({bottom:-50,duration:500});
}
});
The code above hides the tab group when dashWin receives a focus event. However, I see this message in the Titanium console when the event fires while running in the iPhone simulator:
Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
A Google search turns up one result: Another StackOverflow question that may have a hint as to what's going on.
I got this error when I linked Action Segue or Selection Segue from one view to another view through storyboard and performed the same segue programmatically again, which makes the navigation controller perform the same segue twice.
2 solutions for this case:
Removing the code that pushes the view. Just let storyboard perform the segue for you. This is good for most situations.
Replacing Action Segue or Selection Segue with Manual Section and do - (void)performSegueWithIdentifier:(NSString *)identifier sender:(id)sender by yourself. You may find this solution useful when you want to customize the behavior of segue according to the sender.
Usually a tab group acts as the root of your app's navigation. When a user taps a tab, that tab's window is focused.
Next, when a user triggers an action that requires a new window appear, it usually appears either modally or on top (in the navigation stack sense) of the current window. In the latter case, tell the current tab to open the new window.
If you set the tabBarHidden property to false (when you create the new window), the tab bar will be hidden for you when the new window is opened by the current tab.
Will this more standard approach work for you?
I had segues that were leading back to my main navigation controller which was causing this. I fixed the problem by setting the main navigation controller back to the top of the stack. Here is the code:
- (void) viewDidAppear:(BOOL)animated
{
[self.navigationController popToRootViewControllerAnimated:NO];
}
Recently, I've faced the same problem. The reason was:
-I was trying to pop view controller twice by mistake.
you can check this crash by setting breakpoints on push and pop View controllers
I posted earlier but am running into similar problems again. Basically the way that my app is setup there is a top bar that is basically just a static image that has UIButtons placed on top of it. That is the Main View Controller and is persistent no matter what view is shown beneath it. I can't use a navigation controller because it is not possible to change the height and I need the bar to be significantly larger than a navbar. However my bar is functioning in much the same way. There is a "Home" Button, a "Back" Button and several destination buttons.
I understand how to switch views from say the home screen. My confusion comes with the back button. In order to press back the app is going to need to know what view is currently being displayed so that it can be removed from view and a new subview can be added. Ideally I would use the UINavigationController so that I can push and pop views which is really what I want to do here, however that is not possible because of the visual problem.
Does anybody know of a method that returns the current displayed view so I could do something like the following
[currentview.view removeFromSuperView];
[self.view insertSubview:experienceViewController.view atIndex:0]
You can use UINavigationController with the nav bar hidden. Put the nav controller inside a view that does have your jumbo toolbar and you'll have access to the push/pop behavior you're looking for.
I have created an iPhone app where you start in a NavController and after a couple of levels you select an option from the table and an animated view pops in that has a tabbarcontroller at its root.
This is a completely seperate view that replaces the navcontroller. You tab around and when you want to go back to the options screen you press back and another animated transition plays swapping back the navigation controller removing the tab bar controller and releasing it.
The problem comes with releasing the UITabBarController. If you press the tab buttons to switch between tabs it seems you continually increase the reference count for the view controllers. Then when you call release on the tabBarController reference it will only release the view controller of the selected tab or any tabs you haven't viewed yet, and it takes one of the retain count on the others tabs viewcontrollers. This means you leak all your Model objects, custom cell objects etc from each of the other tabs that were not selected.
As an example of what I am seeing, if you create a new template TabBarController project in xcode and add a viewWillAppear method to the first view controller that prints out the retain count for itself. Start the app and press back and forth on the First and Second tab buttons and watch the log the retain count just keeps increasing.
So I am wondering if there is a way to release a tab bar controller and have it release all of its view controllers at the same time?
If this is true, it's a bug, and you should file a report on Apple Radar.
Just for completeness, I did post this problem in the apple dev forums looking for some confirmation but never heard anything back.
Checking out my app on OS3.0 shows that this behaviour is now fixed. Reference counts never go increase and releasing the UITabBarController appears to work.
Sadly I put a nasty hack in to fix this which doesn't play well with OS 3.0 so it's now conditional compilation time.