My environment is Yosemite 10.10.5 with Xcode 7.2 using ARC.
In a simple test program, I am attempting various ways to dismiss a NSViewController and all of them are showing problems with memory handling.
In my primary view controller, I have the following code. (The notification pieces are there to test various ways of dismissing the presented controller.)
- (IBAction)showFirstReplacement:(id)sender {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(dismissWithNotification:) name:#"removeFirst" object:nil];
NSStoryboard *sb = [self storyboard];
FirstReplacement *controller = [sb instantiateControllerWithIdentifier:#"first_replacement"];
[self presentViewControllerAsSheet:controller];
}
- (void)dismissWithNotification:(NSNotification *)notification {
NSViewController *controller = [notification object];
[self dismissViewController:controller];
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
Inside FirstReplacement, I have:
- (IBAction)dismiss:(id)sender {
[self dismissViewController:self];
// [[NSNotificationCenter defaultCenter] postNotificationName:#"removeFirst" object:self];
// [[self presentingViewController] dismissViewController:self];
}
Uncommenting any one of the three lines in this method produces the correct visual results but.... Depending on which of the calls I enable inside dismiss:, I get different results when profiling. Using self dismissViewController:, I see no leaks but FirstReplacement objects are not deallocated. Using either of the other two approaches gets rid of the dismissed FirstReplacement but leaks one 16-byte malloc block and one NSMutableArray every time a view controller is dismissed.
According to Instruments, the leaks are related to a method called [NSViewController _addPresentedViewController:].
Are there other clean-up steps necessary to prevent these leaks (or memory bloat in the non-leak case)?
The view controller that presents another view controller is also responsible for dismissing it. So none of the lines in FirstReplacement's dismiss method are correct. Instead, you should be creating a delegate in FirstReplacement so it can notify its delegate (the primary view controller) that it should be dismissed.
FirstReplacement.h
#class FirstReplacement;
#protocol FirstReplacementDelegate <NSObject>
- (void)firstReplacementShouldDismiss:(FirstReplacement *)controller;
#end
#interface FirstReplacement : NSViewController
#property (nonatomic, weak) id<FirstReplacementDelegate> delegate;
#end
FirstReplacement.m
- (IBAction)dismiss:(id)sender {
[self.delegate firstReplacementShouldDismiss:self];
}
Then in your primary view controller:
- (IBAction)showFirstReplacement:(id)sender {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(dismissWithNotification:) name:#"removeFirst" object:nil];
NSStoryboard *sb = [self storyboard];
FirstReplacement *controller = [sb instantiateControllerWithIdentifier:#"first_replacement"];
controller.delegate = self;
[self presentViewControllerAsSheet:controller];
}
- (void)firstReplacementShouldDismiss:(FirstReplacement *)controller {
[self dismissViewController:controller];
}
While it may seem like posting a notification is the same as a delegate, it is not. The difference is that when dismissWithNotification fires, you are still executing the code from FirstReplacement::dismiss. NSNotificationCenter::postNotificationName does not finish executing until all observers have finished executing their selectors. So even though the dismissal code is executing in the primary view controller, it still being run from the dismiss method.
If you are still not convinced, override FirstReplacement::dealloc to print a log statement. You will see that dealloc is not called using any of your methods, but will be called using delegation.
I have UITabBarViewController which has 2 views.
The first view has a UITableView which has 1 section and 5 rows.
The second view has a UITableView as well which has a settings options like UISwitches.
My question is how can I show and hide or remove a cell from first view by using UISwitches on the settings view? Thanks in advance.
edit
this video explain what i am trying to do (check the app view)
Press Here
you can accomplish this by using NSNotificationCenter
in your firstView you can write a code like:
-(void)viewDidLoad{
[[NSNotificationCenter defaultCenter] removeObserver:self];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(modifyCell:) name:#"modifyCell" object:nil];
}
//make sure this is declared in your .h
-(void)modifyCell:(NSNotification*)notif
{
if (notif) {
//cellindex to modify
NSString *cellIndex = [[notif userInfo] objectForKey:#"index"];
[yourDataSource removeObjectAtIndex:[cellIndex intValue]]
[yourTableView reloadData];
}
}
in your secondView:
-(void)switchChanged
{
NSNotificationCenter *ncSubject = [NSNotificationCenter defaultCenter];
NSDictionary* dict = [NSDictionary dictionaryWithObjectsAndKeys:#"indexNum",#"index", nil];
[ncSubject postNotificationName:#"modifyCell" object:nil userInfo:dict];
[ncSubject removeObserver:self];
}
You should reload your tableview after each UISwitch change. Such as:
- you set a delegate from your UISwitch to your UITabBarViewController (or the class which controls the events)
- you should store your tableview's cells' number in a variable
- this variable will change after each UISwitch change
- after the variable change, you should reload the tableview
In the viewWillAppear method of the table view controller I would check whether the setting has been changed or not. If it has changed then I would redraw the cell by calling its the reloadData method.
Sometimes it is recommended to call reloadData through performSelectorOnMainThread:
[ self performSelectorOnMainThread:#selector(reloadData) withObject:nil waitUntilDone:NO]
And your data loading methods (numberOfSectionsInTableView, numberOfRowsInSection, cellForRowAtIndexPath, etc.) will have to consider the settings value accordingly.
in my universal app, I have a UIControl View inside of a UIScrollView.
On pressing a setup Button, I add another View as subview, like this:
SetupController *setupview = [[SetupController alloc] initWithNibName:#"SetupView-iPad" bundle:nil];
[mainview addSubview:setupview.view];
The subview is displayed like expected.
In this SubView I have some Buttons, which allows the user to switch between settings.
The performed actions are saved in a local Database.
The problem is: On ButtonClick in the SubView, I have to refresh the mainview, to apply the changes. I've tested many ways to make this happen:
In the Subviews class:
[self.parentViewController.view setNeedsDisplay];
No result.
Then I tried to refresh the mainview by notification:
I added this to my subviews classfile, in the function that changes my settings.
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
[nc postNotificationName:#"setEmoticon_NOTIFICATION" object:self];
}
Then I added the observer to my mainview in the ViewDidLoad method:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(refreshView) name:#"setEmoticon_NOTIFICATION" object:nil];
and created the function for this observer:
-(void)refreshView{
NSLog(#"Notification!");
[self.view performSelectorOnMainThread:#selector(setNeedsDisplay) withObject:nil waitUntilDone:YES];
}
In Log I get the "Notification!" on changing the settings. But whatever I try, no refresh.
I tried setNeedsDisplay, resignFirstResponder, [self viewDidLoad:] , but still nothing works.
Any ideas how to refresh my mainview?
What exactly do you need to do when refreshing? Do you need to redraw elements on screen, etc?
Do you have a custom refresh method you've implemented in the main view? I would setup a custom protocol in your sub view and before adding the sub view to the main view, I would add the sub view's delegate as the main view
SetupController *setupview = [[SetupController alloc] initWithNibName:#"SetupView-iPad" bundle:nil];
setupView.delegate = mainview;
[mainview addSubview:setupview.view];
Then handle the refresh in the main view call back.
Hell yeah, seems like I found a solution to refresh my superview from subview.
You only have to add the following code snippet to the desired action/method, that should perform the refresh, in your subview controller.
for (UIView* next = [self.view superview]; next; next = next.superview)
{
UIResponder* nextResponder = [next nextResponder];
if ([nextResponder isKindOfClass:[UIViewController class]])
{
[(UIViewController*)nextResponder viewWillAppear:YES];
}
}
In this case I reload the superview, using it's viewWillAppear method.
You can replace it with any method that fits your needs (viewDidLoad, viewWillDissapear etc.).
It may not be the best way to do this, but it works great for me.
Thanks for your answers. ;)
I'm having a problem with my navigation controller. If I add a view controller to the stack:
- (void) tui_ToggleListStudy:(id)sender
{
listVC = [[ListViewController alloc] init];
[self.navigationController pushViewController:listVC animated:NO];
[listVC release];
}
I have NSLog messages for the view controller beneath, for both viewWillDisappear: and viewDidDisappear - but only viewWillDisappear: is getting called.
Not only that, but the view controller doesn't receive any other delegate messages either: No viewDidUnload, or dealloc...
Is there anything I can do about this?
I'm stumped! Any thoughts?
Thanks!
I know the answer if you made the same typo in your code that you made in your question: the method signature is viewDidDisappear: (with the animated argument), not viewDidDisappear.
Not only that, but the view controller doesn't receive any other delegate messages either: No viewDidUnload, or dealloc...
A view controller will not be deallocated when you push another controller onto the stack. And viewDidUnload won't be called unless you run out of memory.
Assuming your navigation controller is contained in some kind of top view controller, you must also forward the relevant messages from that top view controller to the nav controller:
-(void)viewWillAppear:(BOOL)animated
{
[navController viewWillAppear:animated];
}
-(void)viewDidAppear:(BOOL)animated
{
[navController viewDidAppear:animated];
}
-(void)viewWillDisappear:(BOOL)animated
{
[navController viewWillDisappear:animated];
}
-(void)viewDidDisappear:(BOOL)animated
{
[navController viewDidDisappear:animated];
}
You must call super at implementation of viewWillDisappear.
The designated initializer for UIViewController is -initWithNibName:bundle:. Are you sure your view controller is finding its nib and finds its connected view? I'll bet if you set a breakpoint after init'ing your ListViewController, you'll find its -view returns nil.
I have quite a few controls scattered throughout many table cells in my table, and I was wondering if there's an easier way to dismiss the keyboard without having to loop through all my controls and resigning them all as the first responder. I guess the question is.. How would I get the current first responder to the keyboard?
Try:
[self.view endEditing:YES];
You can force the currently-editing view to resign its first responder status with [view endEditing:YES]. This hides the keyboard.
Unlike -[UIResponder resignFirstResponder], -[UIView endEditing:] will search through subviews to find the current first responder. So you can send it to your top-level view (e.g. self.view in a UIViewController) and it will do the right thing.
(This answer previously included a couple of other solutions, which also worked but were more complicated than is necessary. I've removed them to avoid confusion.)
You can send a nil targeted action to the application, it'll resign first responder at any time without having to worry about which view currently has first responder status.
Objective-C:
[[UIApplication sharedApplication] sendAction:#selector(resignFirstResponder) to:nil from:nil forEvent:nil];
Swift 3.0:
UIApplication.shared.sendAction(#selector(resignFirstResponder), to: nil, from: nil, for: nil)
Nil targeted actions are common on Mac OS X for menu commands, and here's a use for them on iOS.
To be honest, I'm not crazy about any of the solutions proposed here. I did find a nice way to use a TapGestureRecognizer that I think gets to the heart of your problem: When you click on anything besides the keyboard, dismiss the keyboard.
In viewDidLoad, register to receive keyboard notifications and create a UITapGestureRecognizer:
NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
[nc addObserver:self selector:#selector(keyboardWillShow:) name:
UIKeyboardWillShowNotification object:nil];
[nc addObserver:self selector:#selector(keyboardWillHide:) name:
UIKeyboardWillHideNotification object:nil];
tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(didTapAnywhere:)];
Add the keyboard show/hide responders. There you add and remove the TapGestureRecognizer to the UIView that should dismiss the keyboard when tapped. Note: You do not have to add it to all of the sub-views or controls.
-(void) keyboardWillShow:(NSNotification *) note {
[self.view addGestureRecognizer:tapRecognizer];
}
-(void) keyboardWillHide:(NSNotification *) note
{
[self.view removeGestureRecognizer:tapRecognizer];
}
The TapGestureRecognizer will call your function when it gets a tap and you can dismiss the keyboard like this:
-(void)didTapAnywhere: (UITapGestureRecognizer*) recognizer {
[textField resignFirstResponder];
}
The nice thing about this solution is that it only filters for Taps, not swipes. So if you have scrolling content above the keyboard, swipes will still scroll and leave the keyboard displayed. By removing the gesture recognizer after the keyboard is gone, future taps on your view get handled normally.
This is a solution to make the keyboard go away when hit return in any textfield, by adding code in one place (so don't have to add a handler for each textfield):
consider this scenario:
i have a viewcontroller with two textfields (username and password).
and the viewcontroller implements UITextFieldDelegate protocol
i do this in viewDidLoad
- (void)viewDidLoad
{
[super viewDidLoad];
username.delegate = self;
password.delegate = self;
}
and the viewcontroller implements the optional method as
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
[textField resignFirstResponder];
return YES;
}
and irrespective of the textfield you are in, as soon as i hit return in the keyboard, it gets dismissed!
In your case, the same would work as long as you set all the textfield's delegate to self and implement textFieldShouldReturn
A better approach is to have something "steal" first responder status.
Since UIApplication is a subclass of UIResponder, you could try:
[[UIApplication sharedApplication] becomeFirstResponder]
[[UIApplication sharedApplication] resignFirstResponder]
Failing that, create a new UITextField with a zero sized frame, add it to a view somewhere and do something similar (become followed by resign).
Tuck this away in some utility class.
+ (void)dismissKeyboard {
[self globalResignFirstResponder];
}
+ (void) globalResignFirstResponder {
UIWindow * window = [[UIApplication sharedApplication] keyWindow];
for (UIView * view in [window subviews]){
[self globalResignFirstResponderRec:view];
}
}
+ (void) globalResignFirstResponderRec:(UIView*) view {
if ([view respondsToSelector:#selector(resignFirstResponder)]){
[view resignFirstResponder];
}
for (UIView * subview in [view subviews]){
[self globalResignFirstResponderRec:subview];
}
}
#Nicholas Riley & #Kendall Helmstetter Geln & #cannyboy:
Absolutely brilliant!
Thank you.
Considering your advice and the advice of others in this thread, this is what I've done:
What it looks like when used:
[[self appDelegate] dismissKeyboard]; (note: I added appDelegate as an addition to NSObject so I can use anywhere on anything)
What it looks like under the hood:
- (void)dismissKeyboard
{
UITextField *tempTextField = [[[UITextField alloc] initWithFrame:CGRectZero] autorelease];
tempTextField.enabled = NO;
[myRootViewController.view addSubview:tempTextField];
[tempTextField becomeFirstResponder];
[tempTextField resignFirstResponder];
[tempTextField removeFromSuperview];
}
EDIT
Amendment to my answer to included tempTextField.enabled = NO;. Disabling the text field will prevent UIKeyboardWillShowNotification and UIKeyboardWillHideNotification keyboard notifications from being sent should you rely on these notifications throughout your app.
Quick tip on how to dismiss the keyboard in iOS when a user touches anywhere on the screen outside of the UITextField or keyboard. Considering how much real estate the iOS keyboard can take up, it makes sense to have an easy and intuitive way for your users to dismiss the keyboard.
Here's a link
A lot of overly-complicated answers here, perhaps because this is not easy to find in the iOS documentation. JosephH had it right above:
[[view window] endEditing:YES];
Here's what I use in my code. It works like a charm!
In yourviewcontroller.h add:
#property (nonatomic) UITapGestureRecognizer *tapRecognizer;
Now in the .m file, add this to your ViewDidLoad function:
- (void)viewDidLoad {
//Keyboard stuff
tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(didTapAnywhere:)];
tapRecognizer.cancelsTouchesInView = NO;
[self.view addGestureRecognizer:tapRecognizer];
}
Also, add this function in the .m file:
- (void)handleSingleTap:(UITapGestureRecognizer *) sender
{
[self.view endEditing:YES];
}
Even Simpler than Meagar's answer
overwrite touchesBegan:withEvent:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[textField resignFirstResponder];`
}
This will dismiss the keyboardwhen you touch anywhere in the background.
You should send endEditing: to working window being the subclass of UIView
[[UIApplication sharedApplication].windows.firstObject endEditing:NO];
In your view controller's header file add <UITextFieldDelegate> to the definition of your controller's interface so that it conform to the UITextField delegate protocol...
#interface someViewController : UIViewController <UITextFieldDelegate>
... In the controller's implementation file (.m) add the following method, or the code inside it if you already have a viewDidLoad method ...
- (void)viewDidLoad
{
// Do any additional setup after loading the view, typically from a nib.
self.yourTextBox.delegate = self;
}
... Then, link yourTextBox to your actual text field
- (BOOL)textFieldShouldReturn:(UITextField *)theTextField
{
if (theTextField == yourTextBox) {
[theTextField resignFirstResponder];
}
return YES;
}
The best way to dismiss keyboard from UITableView and UIScrollView are:
tableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag
In swift 3 you can do the following
UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
Jeremy's answer wasn't quite working for me, I think because I had a navigation stack in a tab view with a modal dialog on top of it. I'm using the following right now and it is working for me, but your mileage may vary.
// dismiss keyboard (mostly macro)
[[UIApplication sharedApplication].delegate dismissKeyboard]; // call this in your to app dismiss the keybaord
// --- dismiss keyboard (in indexAppDelegate.h) (mostly macro)
- (void)dismissKeyboard;
// --- dismiss keyboard (in indexAppDelegate.m) (mostly macro)
// do this from anywhere to dismiss the keybard
- (void)dismissKeyboard { // from: http://stackoverflow.com/questions/741185/easy-way-to-dismiss-keyboard
UITextField *tempTextField = [[UITextField alloc] initWithFrame:CGRectZero];
UIViewController *myRootViewController = <#viewController#>; // for simple apps (INPUT: viewController is whatever your root controller is called. Probably is a way to determine this progragrammatically)
UIViewController *uivc;
if (myRootViewController.navigationController != nil) { // for when there is a nav stack
uivc = myRootViewController.navigationController;
} else {
uivc = myRootViewController;
}
if (uivc.modalViewController != nil) { // for when there is something modal
uivc = uivc.modalViewController;
}
[uivc.view addSubview:tempTextField];
[tempTextField becomeFirstResponder];
[tempTextField resignFirstResponder];
[tempTextField removeFromSuperview];
[tempTextField release];
}
You may also need to override UIViewController disablesAutomaticKeyboardDismissal to get this to work in some cases. This may have to be done on the UINavigationController if you have one.
Subclass your textfields... and also textviews
In the subclass put this code..
-(void)conformsToKeyboardDismissNotification{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(dismissKeyBoard) name:KEYBOARD_DISMISS object:nil];
}
-(void)deConformsToKeyboardDismissNotification{
[[NSNotificationCenter defaultCenter] removeObserver:self name:KEYBOARD_DISMISS object:nil];
}
- (void)dealloc{
[[NSNotificationCenter defaultCenter] removeObserver:self];
[self resignFirstResponder];
}
In the textfield delegates (similarly for textview delegates)
-(void)textFieldDidBeginEditing:(JCPTextField *)textField{
[textField conformsToKeyboardDismissNotification];
}
- (void)textFieldDidEndEditing:(JCPTextField *)textField{
[textField deConformsToKeyboardDismissNotification];
}
All set.. Now just post the notification from anywhere in your code. It will resign any keyboard.
And in swift we can do
UIApplication.sharedApplication().sendAction("resignFirstResponder", to: nil, from: nil, forEvent: nil)
To dismiss a keyboard after the keyboard has popped up, there are 2 cases,
when the UITextField is inside a UIScrollView
when the UITextField is outside a UIScrollView
2.when the UITextField is outside a UIScrollView
override the method in your UIViewController subclass
you must also add delegate for all UITextView
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.view endEditing:YES];
}
In a scroll view, Tapping outside will not fire any event, so in that case use a Tap Gesture Recognizer,
Drag and drop a UITapGesture for the scroll view and create an IBAction for it.
to create a IBAction, press ctrl+ click the UITapGesture and drag it to the .h file of viewcontroller.
Here I have named tappedEvent as my action name
- (IBAction)tappedEvent:(id)sender {
[self.view endEditing:YES]; }
the abouve given Information was derived from the following link, please refer for more information or contact me if you dont understand the abouve data.
http://samwize.com/2014/03/27/dismiss-keyboard-when-tap-outside-a-uitextfield-slash-uitextview/
I hate that there's no "global" way to programmatically dismiss the keyboard without using private API calls. Frequently, I have the need to dismiss the keyboard programmatically without knowing what object is the first responder. I've resorted to inspecting the self using the Objective-C runtime API, enumerating through all of its properties, pulling out those which are of type UITextField, and sending them the resignFirstResponder message.
It shouldn't be this hard to do this...
It's not pretty, but the way I resign the firstResponder when I don't know what that the responder is:
Create an UITextField, either in IB or programmatically. Make it Hidden. Link it up to your code if you made it in IB.
Then, when you want to dismiss the keyboard, you switch the responder to the invisible text field, and immediately resign it:
[self.invisibleField becomeFirstResponder];
[self.invisibleField resignFirstResponder];
You can recursively iterate through subviews, store an array of all UITextFields, and then loop through them and resign them all.
Not really a great solution, especially if you have a lot of subviews, but for simple apps it should do the trick.
I solved this in a much more complicated, but much more performant way, but using a singleton/manager for the animation engine of my app, and any time a text field became the responder, I would assign assign it to a static which would get swept up (resigned) based on certain other events... its almost impossible for me to explain in a paragraph.
Be creative, it only took me 10 minutes to think through this for my app after I found this question.
A slightly more robust method I needed to use recently:
- (void) dismissKeyboard {
NSArray *windows = [UIApplication sharedApplication].windows;
for(UIWindow *window in windows) [window endEditing:true];
// Or if you're only working with one UIWindow:
[[UIApplication sharedApplication].keyWindow endEditing:true];
}
I found some of the other "global" methods didn't work (for example, UIWebView & WKWebView refused to resign).
Add A Tap Gesture Recognizer to your view.And define it ibaction
your .m file will be like
- (IBAction)hideKeyboardGesture:(id)sender {
NSArray *windows = [UIApplication sharedApplication].windows;
for(UIWindow *window in windows) [window endEditing:true];
[[UIApplication sharedApplication].keyWindow endEditing:true];
}
It's worked for me
Yes, endEditing is the best option. And From iOW 7.0, UIScrollView has a cool feature to dismiss the keyboard on interacting with the scroll view. For achieving this, you can set keyboardDismissMode property of UIScrollView.
Set the keyboard dismiss mode as:
tableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag
It has few other types. Have a look at this apple document.
In swift :
self.view.endEditing(true)
the easist way is to call the method
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if(![txtfld resignFirstResponder])
{
[txtfld resignFirstResponder];
}
else
{
}
[super touchesBegan:touches withEvent:event];
}
You have to use one of these methods,
[self.view endEditing:YES];
or
[self.textField resignFirstResponder];