I'm trying to make a UIAlertView on my Parse app but for some reason every time I run it, it crashes and I'm taken to ApplicationDelegate where I get a SIGABRT. Here is my alert code, I'm pretty sure I'm not doing anything wrong because it's worked before... Is it because I'm loading data into a tableview from Parse?
func displayAlert(title: String, message: String) {
var alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: { (action) -> Void in
}))
presentViewController(alert, animated: true, completion: nil)
}
Not sure what your issue is. You could simplify the code as follows (Xcode 7b6) by eliminating the empty closure and shortening the arguments when possible. But I don't think this is your problem. Instead, you should show the code where you call this function.
var alert = UIAlertController(title: title, message: message, preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
presentViewController(alert, animated: true, completion: nil)
Related
I am getting the following error:
Attempt to present on Check5GHz: whose view is not
in the window hierarchy!
SplashViewController:
let check5ghz = Check5GHz()
check5ghz.determineIf5GHz()
Here is what Check5GHz looks like:
class Check5GHz: UIViewController {
func determineIf5GHz()-> Void{
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
So it seems like the problem is that one ViewController is trying to launch an UIAlertController found in another ViewController which it does not seem to allow. But I need to have this UIAlertController appear from many different ViewControllers. Could you recommend another way?
extension UIViewController {
func determineIf5GHz()-> Void{
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Click", style:
UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
}
Then in any of your view controllers do this:
self.determmineIf4GHz()
I'm trying to show two UIAlertController's instances continuously, which is like this code block below.
func showAlerts() {
let alertA = UIAlertController(title: "Alert A", message: "This is alert a...", preferredStyle: .alert)
let alertB = UIAlertController(title: "Alert B", message: "This is alert b...", preferredStyle: .alert)
let alertButton1 = UIAlertAction(title: "OK", style: .default, handler: nil)
let alertButton2 = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)
alertA.addAction(alertButton1)
alertA.addAction(alertButton2)
alertB.addAction(alertButton1)
alertB.addAction(alertButton2)
self.present(alertA, animated: true) {
self.present(alertB, animated: true, completion: {
debugPrint("alerts are all shown")
})
}
}
I expect this code to show each alert continuously, which means alertB shows after alertA. But alertB doesn't appear as I expect, with warnings on console saying;
Warning: Attempt to present <UIAlertController: 0x7f7ffde0ace0> on <ContinuousUIAlertController_Experiment.ViewController: 0x7f7ffdd092d0> which is already presenting <UIAlertController: 0x7f7ffde09f90>
If I remember correctly, multiple UIAlertController objects cannot be existed at the same time. So I somehow understand what the warning above tells.
So, then, how can I implement continuous alert showing using completion of UIViewController::present(_:animated:completion:) or with nearly the same logic? (I prefer not to use UIAlertAction's handler)
If there is a solution, please let me know.
I'm struggling with this problem for a few days and I've not addressed yet.
You can't show 2 uialettcontrol at 1time.
But you can show 2nd uialettcontrol on 1st one's uialeraction.
For example
let alertController = UIAlertController(title: "iOScreator", message:
"Hello, world!", preferredStyle: UIAlertControllerStyle.Alert)
alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Destructive,handler: { action in
self.pressed()
}))
func pressed()
{
print("you pressed")
}
On pressed event you can write code for 2nd uialettcontrol.
I have a UIAlertController in which the options are populated from an array and are presented to the user. The user then selects an option from the alert. After this, I have a separate alert that provides the user with a confirmation message that has an okay button.
myAlert.addAction(UIAlertAction.init(title: item, style: .Default, handler: {
(UIAlertAction) in
self.chosenBusiness.append(businessNameData[item]!)
}))
self.presentViewController(myAlert, animated: true, completion: nil)
The code above gathers the data from the array and pushes it into actions in myAlert. The code above is inside of a for loop.
After this I use a function to retrieve the topmost view controller, and then push the next alert.
let top = topMostController()
let alertController = UIAlertController(title: "Location pinned", message: "You've successfully pinned this location, good work!", preferredStyle: UIAlertControllerStyle.Alert)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.Default) {
(result : UIAlertAction) -> Void in
print("OK")
}
alertController.addAction(okAction)
self.presentViewController(myAlert, animated: true, completion: nil)
top.presentViewController(alertController, animated: true, completion: {
_ in
})
The error I receive is:
Attempting to load the view of a view controller while it is
deallocating and is not allowed and may result in undefined behavior.
UIAlertController: 0x1535b1cd0.
Can someone help me with this?
I think this is what you are looking for. The second must be called with the dismissal action of the first. Also, anytime you work with UI, It is safer to use dispatch_async(dispatch_get_main_queue()) {
\\code }
than not if you are not positive you are currently on the main queue.
let firstAlertController = UIAlertController(title: "First", message: "This is the first message.", preferredStyle: UIAlertControllerStyle.Alert)
let secondAlertController = UIAlertController(title: "Second", message: "This is the second message.", preferredStyle: UIAlertControllerStyle.Alert)
let secondDismissAction = UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default, completion: nil)
secondAlertController.addAction(secondDismissAction)
let firstDismissAction = UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default) {
UIAlertAction in
dispatch_async(dispatch_get_main_queue()) {
self.presentViewController(secondAlertController, animated: true, handler: nil)
}
}
firstAlertController.addAction(firstDismissAction)
self.presentViewController(firstAlertController, animated: true, completion: nil)
I'm trying to display a message to my users with alert controller but it wont show
let alert = UIAlertController(title: "Error", message: "Incorrect username/password", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "okay", style: UIAlertActionStyle.Default, handler: nil))
looks like you haven't presented it yet. paste this code where you want to show the alert
self.present(alert, animated: true, completion: nil)
I'm a beginning swift developer, so bear with me here.
I have a multiplayer game app, and from my server (yes, this is a background thread) I receive a signal that a match has been found. Then this snippet is executed
dispatch_async(dispatch_get_main_queue(), {
print("showing dialog")
let dialog = UIAlertController(title: "Game found", message: "You are playing with a person named "+self.player2.getName(), preferredStyle: UIAlertControllerStyle.Alert)
dialog.addAction(UIAlertAction(title: "cancel", style: UIAlertActionStyle.Cancel, handler: nil))
self.presentViewController(dialog, animated: true, completion: nil)
self.labelOpponentName.text = self.player2.getName()
})
However, I get the following error
Attempting to load the view of a view controller while it is deallocating is not allowed and may result in undefined behavior (<UIAlertController: 0x79151e00>)
Also, my labelOpponentName is not updating it's text. Why is that?
There may be another UIAlertController defined inside your function or globally.
dispatch_async(dispatch_get_main_queue(), {
print("showing dialog")
let dialog = UIAlertController(title: "Game found", message: "You are playing with a person named "+self.player2.getName(), preferredStyle: UIAlertControllerStyle.Alert)
dialog.addAction(UIAlertAction(title: "cancel", style: UIAlertActionStyle.Cancel, handler: nil))
self.presentViewController(dialog, animated: true, completion: nil)
self.labelOpponentName.text = self.player2.getName()
})