I'm developing a iphone app based UITabBarController,when open the app,on the first tab item,
I press a button,to add a label to the view,and I close the app.
Next open,the label which added last time still on the first tab item,I did not save the view
in applicationWillTerminate method,why?
And,if I switch to the second tab item,and return the first tab item,the view of first stay as before,is the UIView instance keep alive during the app running time,or what reason?
Thanks.
This is the default behaviour of the tab bar controller. If you want to change it, you have to override the UITabBarControllerDelegate.
And also from iPhone OS 4.0 when you close the application pressing the home button, the app is not really closed. It goes background.
If you want your tab bar controller to work as you mention, go to the initial view. You have to override some App Delegate methods, like
- (void)applicationWillResignActive:(UIApplication *)application
or
- (void)applicationDidEnterBackground:(UIApplication *)application
Related
I have an app with multiple View Controllers. I have a Home screen with "Play / Options / etc.". When you hit Play, you navigate over to the GamePlay View Controller and start playing.
I find that if I'm in the "gameplay" VC and I hit the iPhone's Home button (leaving my app) and then re-launch my app, it puts me right back to the game screen. I'd like to force the app to start on the same "Home" screen every time is it launched.
Suggestions greatly appreciated!
Thanks,
-Ed
in your app's plist add the key UIApplicationExitsOnSuspend and set it to YES.
Your app wont be suspended and youll always start on the home screen
When you press the Home button, the application goes to background. When launched again, application just enters foreground from background. I think you can load the home screen in the following delegate method in AppDelegate
- (void)applicationWillEnterForeground:(UIApplication *)application
You can preserve the state of the game (I don't want to kill that zombie again!) in the following:
- (void)applicationDidEnterBackground:(UIApplication *)application
Hi I am new to iPhone development, I am developing a TabBar app it's contains 5 tabbar Items.
When I am close app at third TabBar viewController screen and again when I am opening app that time same third TabBar viewController screen only opening.
How to set App first screen as a default App opening Screen in iphone.
I need to set first screen as a default opening screen when ever open a app.
Could you please share your ideas here..
When you close the app, it doesn't KILL it, it just suspends it. Unless you set the option to kill it when you close it.
I suggest you read Apple Documentation For Application Flow
And possibly read the other documents Apple have provided for you there if you are new to all of this.
In your application's Info.plist, add a boolean key UIApplicationExitsOnSuspend with the value YES.
This will always exit the app (instead of running in background) when you close it. On opening app again, first view controller will appear instead of where you left it last time.
This is because you are setting your application to be run in background, so whenever you close your app the app will run in background and resume on startUp.
so just do one thing
Go to your info.plist and set value for
Application does not run in background to YES
If application is killed by default it loads all settings in Application Delegate method:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
Here you can modify your root view controller, which I presume is some kind of tab bar view controller.
So there is probably some code in that method which defines which tab to load.
However if you want to show specific tab after application enters in the foreground use Application delegate method:
- (void)applicationWillEnterForeground:(UIApplication *)application
Or
- (void)applicationDidBecomeActive:(UIApplication *)application
When exiting the app by for example pressing the home button on the iPhone the app is not terminated. Instead the execution is suspended but the app will remain in memory until iOS decides to remove it. This means that when you enter the app again it will be in the same state you left it. You can see if the app is still in memory by doubletapping the home button.
When your app becomes active the method applicationDidBecomeActive: in your UIApplicationDelegate will be called. You can implement that method to set the state you want your app to be in when it is restored.
I would not recommend explicitly killing the app when it is suspended. That forces the app to be reloaded each time it is started which will degrade performance.
For more information see Apple's documentation on app states.
I am using xcode4.2 and inside appDidFinishLaunching i am initializing navigationController with my first view and sets the rootViewController of app to navigationController.I want to show the first view every time when app resumes. How i can i do this?
The easiest way I can think of is not using backgrounding. If you set the UIApplicationExitsOnSuspend key in Info.plist, when the user press the home button, your app will quit and next time it is launched it will start over and not resumed from where it was.
Otherwise, you can define – applicationWillEnterForeground: and – applicationDidBecomeActive: to go back to your first view whenever the app is resumed. Have a look at the UIApplicationDelegate reference and Multitasking states.
I know that I should use this when I get an interruption in the app and it comes back:
- (void)applicationDidBecomeActive:(UIApplication *)application
But how would I, when the app becomes active again, dismiss any previously opened view controllers and present the main view controller?
This may depend on your architecture. If you use an UINavigationController to manage your views, you could call popToRootViewController on it to push everything else off the navigation stack and return to the root view (you'd have to maintain a property or something similar in your application delegate). If you have any modal views open, you could maintain a property in your application delegate that contains the currently active modal dialogue (if any) which would be dismissed.
Note though that applicationDidBecomeActive: is also called when the application was put into the background (e.g. because the user went for another app in the meantime) and the user returns to your app (as well as on first launch), so returning to the root view may be something different than the user expects.
I have a window within an iPhone application, which is displayed modally to allow the user to enter their settings for a web service upon 'first run'.
The text fields have helper text set, and when you tap them the keyboard shows and allows you to enter text.
Unfortunately the text fields do not clear the helper text, show the edit caret or show the text being entered (as in the screenshot below).
Any suggestions?
The window is being displayed with [self presentModalViewController:<controller_name> animated:YES];, which may or may not be the cause of this issue - when I run the UI via the Interface Builder 'test' application the text boxes respond like normal.
Clear when editing begins has been set for both fields.
Thanks in advance!
Edited: More information
After the info Bart Gottschalk provided I thought I should add some more information. First, the application is a Navigation Based Application.
Secondly, the test app Bart recommended worked fine, so that takes the modal window and the view out of the equation.
Third, I was presenting the modal view when the -(void)viewWillAppear... delegate method was being called - which may very well be the wrong place... however I'm not 100% sure if I should be presenting the modal view from within the didFinishLaunchingWithOptions of the App Delegate...
(this is happening on Simulator and iPhone 3.1.3)
In Interface Builder did you check the box for "Clear When Editing Begins"? With that checked the text field should clear any value once the use taps to edit which is the behavior I think you're looking for.
You can also set the same property programatically using clearsOnBeginEditing if that is convenient in your code.
My guess is that you've done this and it's not behaving as you expect. Just checking on this as a first step in helping you debug.
Also, does this happen in both the Simulator and on a testing device?
Bart
Edited Below...
This seems strange. Let's strip away everything but the basics of presenting a modal view when the application starts and see what happens.
I've recreated the most basic app (that I know of) to test presenting a modal view controller at launch and verify that field editing works fine. What happens for you when you do the same/similar in a new project?
Here is what I'm doing:
1) Create a new view-based app in Xcode called "ModalViewTest"
2) Create a new UIViewController with xib called ModalViewController
3) In ModalViewController.h add a method
-(IBAction)closeModalView;
4) In ModalViewController.m add the method implementation as
-(IBAction)closeModalView {
[self dismissModalViewControllerAnimated:YES];
}
5) In the ModalViewController.xib create two text fields and set the placeholder text for each to abcd1234 and confirm that "Clear When Editing Begins" is checked.
6) In the ModalViewController.xib add a button "Close" and set Touch Up Inside to fire "closeModalView"
7) In the application delegate (ModalViewTestAppDelegate) add the following import
#import "ModalViewController.h"
8) In the application delegate (ModalViewTestAppDelegate) applicationDidFinishLaunching add the following after the line containing [window makeKeyAndVisible];
ModalViewController *modalViewController = [[ModalViewController alloc] initWithNibName:#"ModalViewController" bundle:nil];
[viewController presentModalViewController:modalViewController animated:YES];
9) Save everything
10) Build and Run this new app
Does editing of the text fields work as expected? If yes, what is different about how you are building and presenting your modalView? If no, then we'll need to dig further to determine what is going on in your environment.
Second Edit Below...
When creating a navigation-based application I did the following to present the modal view at application start. Does this work for you in both your test app as well as your real app?
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// Override point for customization after app launch
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
ModalViewController *modalViewController = [[ModalViewController alloc] initWithNibName:#"ModalViewController" bundle:nil];
[navigationController presentModalViewController:modalViewController animated:YES];
}
Well, I just figured it out, but honestly without the persistence and awesome help from Bart it would have taken much longer and been much more frustrating.
It turns out the problem was that I was using a Window instead of a View in the XIB file. This was why when showing the modal view within the Navigation controller it wouldn't display properly (i.e. only a white screen) and why the UITextField would not work properly when showing the view from the RootViewController.
So, to recap - modal views should have UIView, not UIWindow in the XIB/NIB File.
Thanks for your help Bart!
I have the same problem but in iOS7 only. I solved it by changing the tint color of textField to blue in the Storyboard