I want to present a view Controller after the user Authenticates with Touch ID, here is my code and the error i am getting, I have no idea how to solve it
and the console Shows
Looks like you need to access main thread.try this.
For Swift 2.3
dispatch_async(dispatch_get_main_queue()) {
//place your code to push viewController
}
For Swift 3
DispatchQueue.main.async {
//place your code to push viewController
}
Related
I segue into a view controller in which I have the following views:
NMAMapView
GuidanceManeuverView
GuidanceSpeedView
GuidanceSpeedLimitView
GuidanceEstimatedArrivalView
TravelTimePanel
GuidanceNextManeuverView
and is also a NMAMapLoaderDelegate
I create a map route and display that when the ViewController is displayed.
I segue out of this view controller with the back button - this is all in a Navigation Controller, and the view controller should be deallocated when I segue out of it, however it is staying in memory. Each time I segue into this view controller I create a new view controller and the old view controllers are still active in memory. Because of this after about the 10th time the view controller with the NMAMapView is loaded the app crashes out of memory.
Is there a method that I am supposed to call or something that I am supposed to do to ensure that this view controller is deallocated when I back out of it?
Or am I supposed to re-use the view controller?
I found the issue which came from some HERE example code for function "findCurrentPosition()"
private func findCurrentPosition() {
guard positioningManager.startPositioning() else {
print("Error: Positioning failed to start.")
return
}
// Subscribe to position updates.
var token: NSObjectProtocol?
token = NotificationCenter.default.addObserver(
The "token" above is a strong reference. To fix it I changed it to a weak reference
token? = NotificationCenter.default.addObserver(
I'm working on an app that displays a today extension with some information. When I tap on the today extension, it opens the app and navigates to a subview from the root to display the information. Normally the user would then click the back arrow to go back to the main view, but there is no way to tell if this is actually done. It is possible for the user to go back to the today extension and tap again. When this is done, the subview is opened once again with new information. If this is done a bunch of times, I end up with a bunch of instances of the subview and I have to click the back button on each of them to get back to the main view.
My question: Is it possible to check if the subview is already visible? I'd like to be able to just send updated information to it, instead of having to display an entirely new view.
I am currently handling this by keeping the instance of the UIViewController at the top of my root. If it is not nil, then I just pass the information to it and redraw. If it is nil, then I call performSegue and create a new one.
I just think that there must be a better way of handling this.
Edit: Thanks to the commenter below, I came up with this code that seems to do what I need.
if let quoteView = self.navigationController?.topViewController as? ShowQuoteVC {
quoteView.updateQuoteInformation(usingQuote: QuoteService.instance.getQuote(byQuoteNumber: quote))
}
else {
performSegue(withIdentifier: "showQuote", sender: quote)
}
This is different from the suggested post where the answer is:
if (self.navigationController.topViewController == self) {
//the view is currently displayed
}
In this case, it didn't work because I when I come in to the app from the Today Extension, it goes to the root view controller. I needed to check whether a subview is being displayed, and self.navigationController.topViewcontroller == self will never work because I am not checking to see if the top view controller is the root view controller. The suggestions in this post are more applicable to what I am trying to accomplish.
u can use this extension to check for currently displayed through the UIApplication UIViewController:
extension UIApplication {
class func topViewController(base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
if let nav = base as? UINavigationController {
return topViewController(base: nav.visibleViewController)
}
if let tab = base as? UITabBarController {
if let selected = tab.selectedViewController {
return topViewController(base: selected)
}
}
if let presented = base?.presentedViewController {
return topViewController(base: presented)
}
return base
}
}
and usage example:
if let topController = UIApplication.topViewController() {
if !topController.isKind(of: MainViewController.self) { //MainViewController- the controller u wish to equal its type
// do action...
}
}
I have a problem with the above stated. I can not find the exact information on the forums. Most of them are outdated and I have written the code programmatically. I have a controller that contains a view to edit the profile. I can not access that after changing the function listed below. I have a rootviewcontroller set to something else, but I tried the UiApplication calls anyway and it return nil and I can not open the profile controller. This is the function listed below.
#objc func handleOpen2() {
(UIApplication.shared.keyWindow?.rootViewController as? BaseSlidingController)?.openMenu()
}
Xcode does not give me an error but I can not get my menu to open. My rootviewcontroller is set to something else in app delegate. I have a controller that is used to control the sliding menu when I press the edit profile button.
func openMenu() {
isMenuOpened = true
redViewLeadingConstraint.constant = menuWidth
redViewTrailingConstraint.constant = menuWidth
performAnimations()
setNeedsStatusBarAppearanceUpdate()
}
This code is used to open my side bar menu with the information I need and also to perform animations as well. I was wondering if someone had any idea what I can do different instead in my handleOpen2 function. If you need more code, please let me know. Thanks
On swift 5 version:
(UIApplication.shared.windows.first?.rootViewController as? BaseSlidingController)?.openMenu()
I have an app written in swift that displays location information on different views. I am receiving location updates in AppDelegate (I don't want to use a singleton class since I want the location updates even when the app is in the background).
Now, I am using SWRevealViewController to implement a sidebar menu to toggle between the different views. When a new location update is received, how do I call the function of the viewController that is currently active to update the UI?
I searched a lot and all the solutions that talk about how to find the current UIViewController actually return SWRevealViewController as the current UIViewController, which doesn't help.
I gave it another shot and was able to find my viewController in my app from another view controller. However, I couldn't get my child view controllers app delegate.
Looking forward to other answers...
here's what I did:
let app = UIApplication.sharedApplication().delegate! as! AppDelegate
if let nav = app.window?.rootViewController?.childViewControllers {
nav.forEach { vc in
if let viewControllers = vc as? UINavigationController {
viewControllers.childViewControllers.forEach { vc in
if let x = vc as? ViewController {
print("Got it \(x)")
}
}
}
}
}
i'm fairly new to swift and having some difficulty with unwind segues in a master detail application.
the unwind seems to work fine dismissing my popovers on the iPhone, however when i try the same thing on the iPad, the popover remains.
If i add a dismissViewControllerAnimated to the presenting viewController's unwind handling action, then the iPad version works fine and dismisses the popover, however the iPhone version dismisses the popover and then dismisses the view that presented the popover. i.e. dismisses two views.
I have worked out that the problem is that popover's are automatically dismissed with an unwind when presented modally such as on an iPhone. However when presented as true popovers they don't dismiss with an unwind segue. Could somebody help me figure out how to manage both cases so that only the popover will be dismissed. Thank you very much in advance.
Okay. after a long time working on this i managed to come up with a solution. i used a popoverpresentationcontroller and declared the presenting controller as the delegate. by then adding an additional function forcing the iPhone to use the popover in lieu of the modal presentation, the presentation and dismissal is consistent for the iPhone and iPad. the code is below. I just used a generic UIViewController in the if let vc statement so that I could use this with a popover that's imbedded in a navigation controller also.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let identifier = segue.identifier {
switch identifier {
case "My Segue Identifier" :
if let vc = segue.destinationViewController as? UIViewController {
if let ppc = vc.popoverPresentationController {
ppc.delegate = self
}
}
default: break
}
}
}
additionally you need to add the following function to prevent the modal presentation on the iPhone:
func adaptivePresentationStyleForPresentationController (controller:UIPresentationController)-> UIModalPresentationStyle {
return UIModalPresentationStyle.None
}