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.
Related
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.
I am posting a notification locally in the app when ever I receive a remote notification.
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
{
NSLog(#"Received notification: %#", userInfo);
[[NSNotificationCenter defaultCenter] postNotificationName:#"NEWMESSAGE" object:nil userInfo:userInfo]; }
I have added an observer to the view in the function viewWillAppear() and remove the observer in viewWillDisappear().
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(newMessageReceived:) name:#"NEWMESSAGE" object:nil];
and
[[NSNotificationCenter defaultCenter] removeObserver:self];
My question is I want to override every viewWillAppear and viewWillDisappear functions in all *.m files that use these functions in my app.
or how can I dynamically add an observer (like above) to the present view and remove the observer when that view disappears. it should be like a global action whenever view changes observer to be added and removed when it changes again.
Is this possible? if so please guide me.
thanks in advance.
Some thoughts:
You can subclass UIViewController and implement these method in the subclass-ed view controller class. Then you need to create all your views as the subclass of this UIViewController.
Example:
//Creating a custom subclass of UIViewController
#interface CustomViewController : UIViewController
#end
#implementation CustomViewController
- (void)viewWillAppear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(newMessageReceived:) name:#"NEWMESSAGE" object:nil];
}
- (void)viewWillDisappear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
#end
And create all your view controller as the subclass of CustomViewController.
hello i assign nsnotifiaction in app delegate.m's method and this method call eprox every 30sec, and i wants its notifcation in viewcontroller adn execute method,
here is my code of appdelegate .m
- (void)layoutAnimated:(BOOL)animated{
BOOL yy= self.bannerView.bannerLoaded;
if (yy==1){
self.iAdString=[NSMutableString stringWithString:#"1"];
[[NSNotificationCenter defaultCenter] postNotificationName:#"BannerViewActionWillBegin" object:self];
}
else{
self.iAdString=[NSMutableString stringWithString:#"0"];
[[NSNotificationCenter defaultCenter] postNotificationName:#"BannerViewActionDidFinish" object:self];
}
}
and in viewcontroller.m
//i defined in viewdidload method
- (void)viewDidLoad{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(willBeginBannerViewActionNotification:) name:#"BannerViewActionWillBegin "object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(didFinishBannerViewActionNotification:) name:#"BannerViewActionDidFinish" object:nil];
}
its method are..
- (void)willBeginBannerViewActionNotification:(NSNotification *)notification{
[self.view addSubview:self.app.bannerView];
NSLog(#"come");
}
- (void)didFinishBannerViewActionNotification:(NSNotification *)notification {
NSLog(#"come");
[self.app.bannerView removeFromSuperview];
}
- (void)dealloc{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
I have not getting response of excessing method while method read in appdelegate file.
Please help me.
You have a typo error.
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(willBeginBannerViewActionNotification:) name:#"BannerViewActionWillBegin "object:nil];
//Your error here-------------------------------------------------------------------------------------------------------------------------------------^
You have put a space there.
SideNote: For all notification names, you should/can create a separate file and put all your notification names as constants strings.
const NSString *kBannerViewActionWillBegin=#"BannerViewActionWillBegin";
this will be easier to change the value and no such typo will happen.
From your code what I get is except for the notification name's all other stuff is fine, did you check whether the notification gets fired. Try keeping break points at the notification firing line.
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 need to dismiss my uiimagepicker modal viewcontroller automatically when the application enters the background.i tried to put the code to dismissmodalviewcontroller code in viewdiddissappear method,but its not being called.so i made a reference to the viewcontroller in appdelegate and tried to put it in the applicationdidenterbackgroundmethod but still it is not working.can someone point out the right way to do this
Try to add an NSNotificationCenter observer for UIApplicationDidEnterBackgroundNotification in the UIViewController that you want to dismiss. Use the selector to dismiss the modalview
- (void)viewWillAppear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] addObserver: self
selector: #selector(didEnterBackground:)
name:UIApplicationDidEnterBackgroundNotification
object:nil];
}
- (void)viewWillDisappear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] removeObserver: self
name:UIApplicationDidEnterBackgroundNotification
object:nil];
}
- (void)didEnterBackground:(NSNotification*)note
{
[self.navigationController dismissModalViewAnimated:NO];
}
Best way to remove the modal when app is moving to background and it works fine .
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(dismissView:)
name:UIApplicationDidEnterBackgroundNotification object:nil];
}
- (void)dismissView:(id)sender {
[self dismissModalViewControllerAnimated:YES];
}
- (void)dealloc {
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
Also you can remove observer like this
[[NSNotificationCenter defaultCenter] removeObserver: self
name:UIApplicationDidEnterBackgroundNotification
object:nil];
I don't think you need to go through all that.
From the docs:
If you present several modal view controllers in succession, and thus build a stack of modal view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack.
Try calling [self dismissModalViewController:NO] from the parent view controller in your implementation of - (void) viewDidUnload.
This is untested, but the docs imply that it should do the job for you.