I have an application with Textfields in my MainViewController.m file. There is also a scrollview in that file, so when the keyboard comes up, the view scrolls so the user can see the textfield. The keyboard is dismissed when the user taps on the screen. Everything is working well EXCEPT in the case that the user hits the home button to put the app in the background and then comes back to it. In this case, the keyboard is still up, but my scrollview is down with textfields hidden. Ideally I would like to have the keyboard be dismissed as well.
Having looked into it, the methods that are called are all in the AppDelegate.m file (unfortunately it does not go into ViewDidLoad or any of the View lifecycle methods). How do I dismiss the keyboard from applicationDidEnterBackground in the AppDelegate.m file?
I am kind of a newbie - I have tried making a +dismisskeyboard function in my MainViewController file and calling it from the Appdelegate, but my Textfields are all instance variables and that does not work. I have also tried to create a textfield in my AppDelegate file and then do this -
[_someField becomeFirstResponder];
[_someField resignFirstResponder];
but this also does not work... I can't figure out how to link anything on my storyboard to the AppDelegate property of someField.
Can anyone suggest the correct approach to tackle this problem?
Just register a method for UIApplicationDidEnterBackgroundNotification in your MainViewController class and dismiss your keyboard there. e.g.
Register for the notification
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(receivedNotification:) name:UIApplicationDidEnterBackgroundNotification object:nil];
then add this method
- (void) receivedNotification:(NSNotification *) notification
{
[txtFld resignFirstResponder];
}
Related
I'm using storyboard.
As I remeber (I worked with ios 4, long time ago=)) everytime, when View appears, calls
-(void)viewWillAppear:(BOOL)Animated {}
method.
Now this method doesn't call, if I press Home button and run app again.
How to fix it?
I need to update one UIView if it appears after home pressing.
The function viewWillAppear is not part of UIView. It is part of UIViewController.
It is called after the view controller's view has been loaded and just before it starts to transition onto screen.
If you create a subclass of UIView and put this function in it then it will never be called because it isn't supposed to be.
Edit
You are correct that viewWillAppear does not get called when the app is coming back from the background.
If you want to update a part of your app when this happens then you can do something in the AppDelegate.
I'd recommend not trying to store properties etc... in the AppDelegate though. You should do something like this...
- (void)applicationWillEnterForeground:(UIApplication *)application
{
// Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
// just pass the message on. In your view you will need to add an observer for this notification
[[NSNotificationCenter defaultCenter] postNotificationName:#"UpdateViewNotification" object:nil];
}
try this, call the super,
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}
I've created an app that has two viewcontrollers. The app opens to a title screen (general UIViewController titled 'Title') with a segue connection to the second view that is a custom class (OSViewController titled 'MapView'). As it is, the app suspends when entered into the background state so it opens right where you left off which is typically in MapView.
I want to know what I need to do to have the app start at the title screen when it becomes active. Preferably, I'd like it to open to the title screen if it is inactive for more than 1 minute. From what I've been reading, it seems like I would make a call in applicationDidBecomeActive: method in my AppDelegate to code this in. Please provide me the code to put in the applicationDidBecomeActive: method (if that's the right place to put it) that will reopen my app to the title screen when transitioning from the inactive state to the active state. My app is almost finished but I'd like to fix this issue and I don't have a lot of experience dealing with app states. Thanks in advance for your time.
If you need more information just ask.
You can also register a class as an observer of the "didBecomeActive" notification. You should place this in the viewDidLoad or the init method of your class.
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(willBecomeActive:) name:UIApplicationDidBecomeActiveNotification object:nil];
In this case, willBecomeActive: is a method that you have defined in your class that get's called when the app becomes active again. That might look something like this:
- (void)willBecomeActive:(NSNotification *)notification {
if (self.navigationController.topViewController == self) {
[self.navigationController popToRootViewControllerAnimated:YES];
}
}
You'll also need to add this in your viewDidUnload method
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidBecomeActiveNotification object:nil];
EDIT:
Thanks #AMayes for the advice. I don't believe key/value observing is necessary in this instance.
I am developing an application were everything is working fine, except one i.e. when user press on home while keyboard is in active and again opens my application the view frame bounds are changing and moving out of bounds. My expected result is keyboard should get suspended or the view should stay in the same position when it is come back from background to foreground with keyboard in-active state.
I hope people understand my scenario and reply ASAP.
Thanks.
I have found the solution to my question, i hope people can use my solution. Below is the code what I have done,
Add the below line of code in your RootViewController file (i.e. which view is coming at first when you open your APP).
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(receivedNotification:) name:UIApplicationDidEnterBackgroundNotification object:nil];
And then add a private method as below
- (void) receivedNotification:(NSNotification *) notification
{
if ([username isFirstResponder])
{
[username resignFirstResponder];
}
else if ([password isFirstResponder])
{
[password resignFirstResponder];
}
}
I hope it help some body,Thank u.
Further assistance please see the mentioned link,
there is a method in the app delegate
- (void)applicationDidEnterBackground:(UIApplication *)application
this method is fired when you press the home button.
do the necessary changes(textField resignFirstResponder) in this method and it should work fine i guess.
EDIT here's the code
in the class where you have your textfield create a method
-(void)performWhenHomeBtnprssed
{
[MytextField resignFirstResponder];
}
then in
- (void)applicationDidEnterBackground:(UIApplication *)application
{
[myClassObj performWhenHomeBtnprssed];
}
also i agree with #valexa you should find the root cause of the problem
In software development it is always better to address the root causes than to patch the effect, in your case there are problems with the positioning of your views and you should address that, foreground/background cycling should not affect the views positioning.
In my application, I have a NSWindow that has a NSTableView object and a few buttons. When the user presses the "new" button, an "ItemAdd" NSWindowController is activated where the user types in attributes for the item to be added to the NSTableView.
My question is this: since NSTableView requires reloadDatato update its view, how do I call reloadData after the ItemAdd window closes and focus shifts back to the NSWindow with the NSTableView.
Thanks for the help!
You could put reload data in a notification handler:
Put this in an initialization method of an object that you want the notification to get called on:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(didBecomeMainWindow) name:#"NSWindowDidBecomeKeyNotification" object:nil];
Then make a method something like this:
- (void) didBecomeMainWindow
{
[tableView reloadData];
}
You can subclass the NSWindow and override the following method:
- (void)becomeKeyWindow
Im my application, I display a NSView when a user click on an icon in the systemstatusbar.
This NSView is displayed with MAAttachedWindow.
My question is : how to refresh the NSView content when the attachedWindow is displayed (makeKeyandorderFront)
I've tried to refresh the content in the awakeFromNib method,but it works only once.
Could anyone help me?
thanks
The solution I've found:
I've added a observer in my view:
I've set the object to [selft window] to listen the NSWindowDidBecomeKeyNotification notification of the MAAttachedwindow.
-(void)awakeFromNib
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(windowDidBecomeKey:) name:NSWindowDidBecomeKeyNotification object:[self window]];
}
-(void) windowDidBecomeKey:(NSNotification *)note
{
// Do refresh here
}
The reason -awakeFromNib only works once is presumably because you're only loading the assembly from the xib once and keeping it around.
Presumably whatever action actually shows your view in the MAAttachedWindow instance is the ideal place to "refresh" it before display, ie your own call to -makeKeyAndOrderFront:.
So: What have you tried?