UIAlertController showing with delay

Question

I'm experiencing a problem with UIAlertController on my app now migrated to iOS8 with Date Picker inside.

Below is the code.

UIAlertController *AlertView = [UIAlertController alertControllerWithTitle:title message:nil preferredStyle:UIAlertControllerStyleActionSheet];

 UIAlertAction *ok = [UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action)
{
[AlertView dismissViewControllerAnimated:YES completion:nil];
}];

 UIAlertAction *set = [UIAlertAction actionWithTitle:NSLocalizedString(@"Set to today", nil) style:UIAlertActionStyleDefault handler:^(UIAlertAction *action)
{
[self set_to_today:nil];
[AlertView dismissViewControllerAnimated:YES completion:nil];
[self.tableView reloadData];
}];

 UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action)
{
[AlertView dismissViewControllerAnimated:YES completion:nil];
}];


 UIDatePicker *datePicker = [[[UIDatePicker alloc] init] autorelease];
 datePicker.datePickerMode = UIDatePickerModeDate;
[datePicker setDate:data_appo];
[datePicker addTarget:self action:@selector(datePickerValueChanged:) forControlEvents:UIControlEventValueChanged];

[AlertView.view addSubview:datePicker];
[AlertView addAction:ok];
[AlertView addAction:set];
[AlertView addAction:cancel];
[self.view bringSubviewToFront:datePicker];
[self presentViewController:AlertView animated:YES completion:nil];

UIAlertController and Date Picker is shown when the user select a row from UITableViewController.

The problem is the following: first time the users select the row everything works fine...but if the user select "Cancel" and then select de tate again the UIAlertController takes 2-3 seconds to show up...this happens also in the simulator...

I'm getting crazy....this makes my app have a bad user experience.

Any help will be strongly appreciated Thanks

Alex

Try to replace `self` with `AlertView` in the line with `bringSubviewToFront` and call `dismissViewControllerAnimated:completion:` on `self`. — Felix, Oct 19 '14 at 13:24
If I call "dismissViewControllerAnimated:completion: on self" i get an error...not sure if i'm coding correctly...can you post a sample code? — user3197643, Oct 19 '14 at 14:36

Tomusm · Answer 1 · 2014-12-17T22:59:01.110

92

I was having the same issue with a UIAlertController presented by selecting a row from a UITableView. The first time everything worked fine, and then when the user triggered the alert again there was a few seconds delay before the alert was actually presented.

As a workaround I used GCD:

    dispatch_async(dispatch_get_main_queue(), ^{
        [self presentViewController:AlertView animated:YES completion:nil];
    });

It is probably a bug since -(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath is already executed on the main thread.

I submitted a bug report to Apple: rdar://19285091

edited Dec 17 '14 at 22:59

answered Dec 17 '14 at 22:04

Tomusm

2,208
19
20

5

Tried this, doesn't seem to fix my problem. Still takes 3 seconds to show the alert. – ninjaneer Jan 05 '15 at 00:28
6

I'm seeing the exact same problem with a table view. Thanks, your solution worked for me. – Dave Batton Jan 30 '15 at 16:58
1

still its getting delay – Patel Jigar Nov 05 '15 at 07:13
same here, alert on table view cell click... not fully solving the problem but makes it better – frangulyan Nov 08 '15 at 22:51
I also come across this problem, has not yet been solved – tianglin Nov 25 '15 at 02:58
Yeah, definitely a bug. Using iOS 9.1 and still has this issue. Using dispatch_async seemed to resolve it. Probably will create a category item. Ugly solution, but it is a solution. – Lloyd Sargent Dec 03 '15 at 17:14
Annoying bug! This solution is a gimmick, but fixed my problem successfully! (tested on iOS 8.4 and 9.1) Thanks!! – Gui Del Frate Dec 08 '15 at 06:30
This solution worked for me. Not quite sure why, since nothing should be done in the background here. Oh well... – CoBrA2168 Jan 11 '16 at 22:30
This solved me also the case dismissing a modal on didSelectItem had a delay, with this code is fixed now. Thanks! – Pau Ballada Jul 21 '16 at 08:20
my delay was like 2-3 seconds and this worked for me. thanks – sweepez Aug 18 '16 at 05:14
What the hell? Fixed my delay, how is that even possible? – thibaut noah Jan 11 '17 at 16:23
Worked Like charm. Thanks – Kashif Jilani Feb 07 '17 at 10:43
Dispatching code on main thread worked for me, but I dont know wht this problem happened, since didSelectRow is already called on main thread. – sudhanshu-shishodia Apr 26 '17 at 07:51
Worked on iOS 10.3! Thanks! – Roland T. Aug 22 '17 at 10:48
Sigh, still needed as of iOS 11.x... Very weird indeed, since setting a breakpoint and checking the call stack reveals that `didSelectRow:` is already being executed on the **main** thread... – Nicolas Miari Nov 26 '18 at 05:22
In my case, I was presenting a **custom** modal view controller using `UIViewControllerAnimatedTransitioning`, `UIViewControllerTransitioningDelegate` etc. so it took me checking my own code thoroughly before I tried replacing it with a stock, vanilla `UIAlertController` and notice the delay was still there... – Nicolas Miari Nov 26 '18 at 06:09

score 27 · Answer 2 · answered Mar 06 '17 at 07:36

27

    DispatchQueue.main.async {
        self.present(alertView, animated: true, completion:nil)
    }

Swift 3.0 version. Alternatively, setting animated: false also solved my problem.

answered Mar 06 '17 at 07:36

Mikrasya

964
12
21

UIAlertController showing with delay

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