I have the following snippet of code in viewDidLoad which I post a notification to be received by a different ViewController, and prior to iOS 7 (and XCode 5) this has worked:
if ([PFUser currentUser] && [PFFacebookUtils isLinkedWithUser:[PFUser currentUser]]) {
NSLog(#"Current user exists and is logged in"); //current works, so I know that this if-statement is satisfied
[self performSegueWithIdentifier:#"GoToRatingsView" sender:self];
[[NSNotificationCenter defaultCenter] postNotificationName:#"testSetup" object:nil]; //part in question
}
And in the segued ViewController, I have the following:
(void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(testSetupFunction) name:#"testSetup" object:nil];
}
(void)testSetupFunction
{
NSLog(#"This function executed");
}
Currently, testSetupFunction does not executed, which means the notification is not received. I am unsure whether its because I have segued to a different view and then posted the notification, or that this is something new with iOS 7, but currently the notification is no longer received.
Thanks for your help!
Post the notification once the viewcontroller has time to load.
- (void)postNotificaiton
{
[[NSNotificationCenter defaultCenter] postNotificationName:#"testSetup" object:nil];
}
if ([PFUser currentUser] && [PFFacebookUtils isLinkedWithUser:[PFUser currentUser]]) {
[self performSegueWithIdentifier:#"GoToRatingsView" sender:self];
[self performSelector:#selector(postNotification) withObject:nil afterDelay:0.0];
}
You could also post a notification from your segued View Controller saying that it was loaded, and in response to that notification, post your testSetup notification.
did you try adding the observer in the init method
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(testSetupFunction) name:#"testSetup" object:nil];
// Custom initialization
}
return self;
}
OR You can also try to put a log in viewDidLoad to check actually the view is loaded at that time, sometimes it takes time to load the view, view is only loaded only when it is needed.
Related
I am writing a sprite kit game and I have in app purchase in my game. I implement the in
app purchase in file IAPHelper.m(IAPHelper.m is a subclass of NSObject), and if the
purchase success, it will post a nsnotification,the code is like:
- (void)completeTransaction:(SKPaymentTransaction *)transaction {
NSLog(#"completeTransaction...");
[self provideContentForProductIdentifier:transaction.payment.productIdentifier];
}
- (void)provideContentForProductIdentifier:(NSString *)productIdentifier {
NSLog(#"post a notification");
[[NSNotificationCenter defaultCenter] postNotificationName:IAPHelperProductPurchasedNotification object:productIdentifier userInfo:nil];
}
And in MyScene.m(MyScene.m is a subclass of SKScene), I add an observer for the notification:
-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
/* Setup your scene here */
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(ok:) name:IAPHelperProductPurchasedNotification object:nil];
}
return self;
}
- (void)ok:(NSNotification *)notification {
NSLog(#"Ok, I got it");
}
And What I am trying to do is IAPHelper.m post the notification, and MyScene.m receive it and respond to it. But the result is MyScene.m seems not receiving the notification and thus the code
- (void)ok:(NSNotification *)notification {
NSLog(#"Ok, I got it");
}
is not being called. but if I put the observer in my ViewController.m( subclass of UIViewController), it works. My question is: can skscene receive notification from any object? And if it can, how to implement it.
Many Thanks if anyone can help me with this problem.
i want to reload table when app comes to foreground from background, in my app delegate.m i did like this, but its not working
- (void)applicationWillEnterForeground:(UIApplication *)application
{
NSLog(#"applicationWillEnterForeground");
[[NSNotificationCenter defaultCenter] postNotificationName:#"EnteredForeground"
object:nil];
}
and in my viewController i am working like
- (void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(whenAppEnteredIntoForeground:) name:#"EnteredForeground" object:nil];
}
- (void)whenAppEnteredIntoForeground:(id)object {
NSLog(#"log msg");
[tblSearch reloadData];
}
what should i do? what mistake i am doing? any help please
Firstly, you don't need to rebroadcast a notification when the app comes to the foreground, you can register for the notification from your view controller.
In your case, it's likely to be that the view is not loaded until after your secondary notification is sent, which is why your view controller cannot respond to it. Using breakpoints will confirm if this is the case.
Use this instead:
- (void)viewDidLoad {
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(whenAppEnteredIntoForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];
}
And you don't need to rebroadcast a notification from your appdelegate.
- (void)viewDidLoad {
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(appEnteredIntoForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];
}
- (void)appEnteredIntoForeground:(id)object {
[tableView reloadData];
}
Make sure that your Reload Data must call from main Thread Otherwise it will not be reloaded.
I have a view controller, when it's dissming with completion, I post a notfication, and in a subview which contained in another view controller, has added as a oberserve. But, when it tries to execute post notificaiton methode, exec_bad_access happend. what's wrong? The codes are:
BrandListByIdViewController.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSNumber *bid = self.brands[indexPath.row][#"id"];
[self dismissViewControllerAnimated:YES completion:^{
[[NSNotificationCenter defaultCenter] postNotificationName:#"SelectedBrandId" object:nil];
}];
}
SearchNewProduct.h
#interface SearchNewProduct : UIView
#end
SearchNewProduct.m
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(didSelectedBrandId::) name:#"SelectedBrandId" object:nil];
}
}
- (void)didSelectedBrandId:(NSNotification *)notif{
NSLog(#"%s", __PRETTY_FUNCTION__);
}
Even I get rid of the userInfo, still bad access. I created a similar situation in another new project, it works fine.
I didn't realize that you were dealing with a UIView and not a UIViewController (should have read your question better). I think what is happening is that the View is receiving notifications even after being released. Make sure to call dealloc in your UIView and remove itself as an observer:
- (void)dealloc {
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
Also, put an NSLog in that UIView's initWithFrame method to see if it is being called more than once.
This question is very similar:
ios notifications to "dead" objects
Not sure if this is the reason, but when you add your view to the notification center, your selector is wrong:
selector:#selector(didSelectedBrandId::)
There should only be one colon. The entire line should be:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(didSelectedBrandId:) name:#"SelectedBrandId" object:nil];
Two colons indicates the method takes two arguments, but it only takes one.
what method within a ViewController's class can I call to check when it has been brought to the foreground?
For example Im looking at a page on my application and I decide to close the application and go back to it later. When I go back to it the same view as I was looking at was on the screen. However... As soon as I open the application I want to segue over to another view.
How can I do this?
Currently trying this:
- (void) applicationDidBecomeActive:(NSNotification*) notification
{
[self checkActivity];
// Do your stuff here
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationWillEnterForeground:)
name:UIApplicationWillEnterForegroundNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationDidBecomeActive:)
name:UIApplicationDidBecomeActiveNotification
object:nil];
}
return self;
}
- (void)checkActivity{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSLog(#"Checking if re-authentication required...");
if([[defaults objectForKey:#"shouldgotologin"] isEqualToString:#"yes"]){
NSLog(#"View Should go to login...performing segue");
[defaults setObject:#"no" forKey:#"shouldgotologin"];
[defaults synchronize];
[self performSegueWithIdentifier:#"backtologin" sender:self];
} else {
NSLog(#"Should go to login is not true.");
}
}
Register your view controller to observe UIApplicationWillEnterForegroundNotification:
1) Inside view controller's init method:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationWillEnterForeground:)
name:UIApplicationWillEnterForegroundNotification
object:nil];
2) Inside view controller's dealloc method:
[[NSNotificationCenter defaultCenter] removeObserver:self];
3) Also, have your view controller implement this method:
- (void) applicationWillEnterForeground:(NSNotification*) notification
{
// This method will be called just before entering the foreground;
// Do your stuff here
}
If the timing of UIApplicationWillEnterForegroundNotification doesn't suit you, check all the available notifications for UIApplication here:
http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIApplication_Class/Reference/Reference.html
Jump To ApplicationDelegate File, you will find following methods.
- (void)applicationWillResignActive:(UIApplication *)application
{
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
}
Remember, It is not the viewController who receives the notifications related to the Application states like willResignActive,didEnterBackground,willEnterForeground. ApplicationDelegate object is going to handle those notifications. So, Try putting your logic in above methods.
Hope that helps. If not, add your queries using comments below my answer.
I am trying to post a notification without much success! I can do it
ok for the keyboard without issue but now am trying a custom one as
follows:
In my rootview I have this
.h
-(void) allowEdits:(NSNotification *)notification;
.m
//this section is run in method to present the passcode entry form
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(allowEdits:) name: #"PasscodeOK" object:nil];
PasscodeEntryViewController *vc = [[PasscodeEntryViewController alloc]
init];
[self presentModalViewController: vc animated:YES];
[vc release];
// and this is the response to the notification
-(void) allowEdits:(NSNotification *)notification {
NSLog(#"notification fired");
}
// in the vc instance I have this to notify passcode was ok
[[NSNotificationCenter defaultCenter]
postNotificationName:#"PasscodeOK" object:nil];
[self dismissView];
But the allowEdits never gets called?
Could you try posting your notification with:
[[NSNotificationCenter defaultCenter] postNotificationName:#"PasscodeOK" object:self];
As sender take the vc instance (self) instead of nil. Maybe that's solving your problem.