In my iOS app, I have several Firebase event listeners in place as the user performs different functions. I am encountering an issue where the app crashes (only sometimes) specifically when the user terminates it by double-tapping the home button and swiping up. In the applicationWillTerminate function of AppDelegate.swift, I simply remove all registered event listeners:
func applicationWillTerminate(_ application: UIApplication) {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
Home.globalEvents = []
removeListeners()
}
private func removeListeners()
{
UserService.userEventListener?.remove()
UserService.friendIDListener?.remove()
UserService.groupListener?.remove()
UserService.postListener?.remove()
Home.requestListener?.remove()
Home.eventsListener?.remove()
Home.inviteListener?.remove()
Home.requestCount = 0
Home.inviteCount = 0
Home.publicEventListener?.remove()
Home.privateEventListener?.remove()
ProfileFinder.requestListener?.remove()
}
This gives me the error message:
"Assertion failure in auto FSTLocalStore::releaseQuery:::(anonymous class)::operator()() const()"
Can anyone clue me in as to why what I'm doing is problematic? Thanks.
Related
I have a webview on Android that always checks if there is internet coming back from the background checking if the connection status has changed if it is offline the application sends the user to a "reconnect and try again" screen using the code below:
protected void onResume() {
super.onResume();
mWebView.onResume();
if (isConnected(getApplicationContext())){
} else {
Intent i = new Intent(MainActivity.this, off.class);
startActivity(i);
overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);
finish();
}
}
So far I have made a version for ios of this webview but I could not reproduce this check when the app returns from the background, how do I reproduce this "onresume" in ios swift? (the code that checks the connection state I already have)
In AppDelegate use the following method:
func applicationWillEnterForeground(_ application: UIApplication) {
// 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.
print("Enter foreground")
}
Subscribe for UIApplication.willEnterForegroundNotification and check the connection immediately after it's fired.
** i have gone through similar questions but havent been able to solve the problem..the error only occurs when i add any label or imageview but works fine when i change background color
any help will be greatly appreciated(stuck on this since evening). Thanks in advance!
hey guys I'm trying to build a simple ios project(fairly new to swift) and whenever i try to run my code in simulator i always get an error shown in the picture below. All i have done in this project so far is add a label and change background but when i run the code it shows succeeded but fails to run in any simulator and points me to the appdelegate.swift file Appdelegate Thread 1: breakpoint 1.2 error
This is my code:
AppDelegate.swift
import UIKit
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
return true
}
func applicationWillResignActive(_ application: UIApplication) {
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}
func applicationDidEnterBackground(_ application: UIApplication) {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
func applicationWillEnterForeground(_ application: UIApplication) {
// 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.
}
func applicationDidBecomeActive(_ application: UIApplication) {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
func applicationWillTerminate(_ application: UIApplication) {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
}
viewcontroller.swift
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
In my main.storyboard i have just added a label and changed background color
You've assumed this was an error but it's actually a debugging breakpoint. You inadvertently set a breakpoint which is easy to do. Where the line is green, it says breakpoint but does not say error.
To remove any breakpoints, click on the blue arrow seen in your screenshot. With the breakpoints removed, the code should run normally.
well, that just a debugging breakpoint is shown in the image If you have added breakpoints that is completely fine.
Either remove all breakpoints and try to run the program and check if it still stops there.
if you added an exceptional breakpoint then do this shown in the image below
So, on my app I have a feed that I want to update every time the user returns to the app.
I'm calling a routine to do this on applicationWillEnterForeground of my AppDelegate.
Everything is working fine but, sometimes, my UI freezes during this operation.
I was able to find where this occurs using a label to show the progress of this routine. The label is updated on three major points:
Before starting the routine
Inside the routine
When the routine ends
Sometimes, this workflow works fine, and I'm able to see the progress through this label.
But sometimes, the label only shows the first message, and messages that happen inside the routine does not appear. Besides that, I can't do anything on my app, because the UI is frozen. Once the routine is over, everything comes back to normal.
Here's a simplified version of the flow my app executes to call this routine:
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
let mainViewController = MainViewController()
func applicationWillEnterForeground(_ application: UIApplication) {
mainViewController.refreshLatestVideos()
}
}
class MainViewController: UITabBarController {
private var subscriptionsController: SubscriptionsController! // initialized on viewDidLoad
func refreshLatestVideos() {
subscriptionsController.refreshLatestVideos(sender: nil)
}
}
class SubscriptionsController: UITableViewController {
private var subscriptionsModelController: SubscriptionsModelController! // received on constructor
#objc func refreshLatestVideos(sender:UIButton!) {
showMessage(message: "Updating subscriptions...") // this message is always shown to me
subscriptionsModelController.loadLatestVideos()
}
}
class SubscriptionsModelController {
func loadLatestVideos() {
UIApplication.shared.isNetworkActivityIndicatorVisible = true
DispatchQueue.global(qos: .userInitiated).async {
// bunch of requests with Just
...
// update message
showMessage(message: "Updating subscription x of y") // this message sometimes doesn't appear, because the UI is frozen
// another requests
...
// update message
showMessage(message: "Updates completed")
}
}
}
As you can see, I'm executing the update inside the global queue, so I'm not blocking the main thread.
And again, this freezing of the UI only happens sometimes.
Is there any point which I can look at to find what's going on? Is it possible that the main thread is being blocked by something else?
Dispatch updating the UI to the main thread:
DispatchQueue.main.async { showMessage(message: "Updates completed") }
Everytime you anyhow access/modify the UI, do it on the main thread to avoid having unexpected problems (link to one of several resources on this topic, I suggest you google up and read more).
That applies to the rest of the code as well, if there is something that is related to UI, do the same for it - e.g., if after finishing the task you call tableView.reloadData, do it on the main thread too.
When I restart app from here: https://github.com/zweigraf/face-landmarking-ios picture from camera doesn't appear and printing error: "Ignoring enqueueSampleBuffer because status is failed".
The problem is probably in captureOutput from SessionHandler.swift
I find a solution! Thanks to Why does AVSampleBufferDisplayLayer fail with Operation Interrupted (-11847)?
If you had similar problem you need to set AVSampleBufferDisplayLayer each time app entering foreground. Like this:
//AppDelegate.swift
func applicationWillEnterForeground(_ application: UIApplication) {
// 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.
viewcontroller?.setLayer()
}
//ViewController.swift
func setLayer() {
sessionHandler.layer = AVSampleBufferDisplayLayer()
sessionHandler.layer.frame = preview.bounds
sessionHandler.layer.videoGravity = AVLayerVideoGravityResizeAspectFill
preview.layer.addSublayer(sessionHandler.layer)
}
and don't forget to remove sublayer:
func applicationDidEnterBackground(_ application: UIApplication) {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
viewcontroller?.sessionHandler.layer.removeFromSuperlayer()
}
So I have been trying to make an app for my Mobile Apps Development class and I need to find a solution to a problem that I'm having when I save a global array called "events".
Here I tried to reload the saved event class in AppDelegate but it didn't change in the main screen view controller:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
//Override point for customization after application launch.
//Load the events that were saved when application was terminated
let eventKey = NSUserDefaults.standardUserDefaults()
Global.events = (eventKey.arrayForKey("savedEvents") as? [Event])!
return true
}
Here is the function that is called when someone quits the app:
func applicationWillTerminate(application: UIApplication) {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
let myEvents = Global.events
NSUserDefaults.standardUserDefaults().setObject(myEvents, forKey: "savedEvents")
NSUserDefaults.standardUserDefaults().synchronize()
}
This might just be an error in the viewcontroller that displays this array but if you see something wrong with the code please let me know.
Two problems:
In iOS, there is no such thing as "someone quits the app", and thus what you're doing is unlikely to work, because applicationWillTerminate is never called. Save when the application is deactivated or backgrounded.
An array of Event cannot magically be saved in user defaults, because Event is not a Property List type. You will need to make Event archivable and archive the array.