Navigating to ViewController containing ScrollView Going too Slow

Question

This is how am pushing from ViewController A to ViewController B

UIStoryboard *mainStory = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
ListingViewController *listView = [mainStory instantiateViewControllerWithIdentifier:@"listing"];

[self.navigationController pushViewController:listView animated:YES];

and i've tried this way as well using a segue in StoryBoard

[self performSegueWithIdentifier:@"Associate3" sender:sender];

Pushing to this ViewController for the first time freezes (around 4 sec) before start pushing, knowing that VC B contains UIScrollView Object in its XIB,

Did this happened to any of you, any one knows how to solve this delay?

EDIT:

i've already commented all webservice calling methods, nothing Changed! I think its an allocating delay, am using the storyboard initiating with identifier to push VC B, but when i used allocating method: VC *B = [[VC alloc] init], then pushing to this view works without delay, but the issue that i don't need to use the allocating method!!

yes am calling httprequest after the view did load to read JSON, — samir, Jan 18 '16 at 07:58
but am doing the same when am pushing to other views (HttpRequest) that don't contain ScrollView, its just pushing fine, except this one that has ScrollView in its IB !! — samir, Jan 18 '16 at 08:01
@Samir please call your webservice in viewDidAppear instead of viewDidLoad. I hope you will get your solution. — Dharmbir Singh, Jan 18 '16 at 08:02
unfortunately, i've tried to do so, but the same result, as i told, am sure its something related by the ScrollView that is added in the IB of VC B — samir, Jan 18 '16 at 08:13
This time profiler thing can't solve my problem, i hate these encrypted stuff :@ — samir, Jan 19 '16 at 07:09

score 2 · Accepted Answer · answered Jan 22 '16 at 09:15

Finally found the issue, it was the custom font that am using in the labels of the VC B, just set them back to System Font instead of Roboto solved my problem, i think the system takes time to find the Font with specific name. Hope this would be useful for others

score 0 · Answer 2 · answered Jan 18 '16 at 08:05

0

It seems you are performing some heavy operation on main thread in ViewWillAppear or ViewDidLoad of ViewController B

Comment whole code of both above mentioned methods and then run your application which verifies problem in app.

So if its verified then you must move your heavy operation from main thread to background thread.

answered Jan 18 '16 at 08:05

Aamir

16,329
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59
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Tried to do so, the same result, am sure its all about the ScrollView object that i added in the IB of VC B – samir Jan 18 '16 at 08:14
ok then remove ScrollView from IB and then share your results. – Aamir Jan 18 '16 at 08:18
Again, nothing changed .. thats making me crazy!! – samir Jan 18 '16 at 08:31
well it showing that ScrollView has nothing to do with it, now remove all items and try with single UILabel in it. – Aamir Jan 18 '16 at 08:33
left label only in the IB, its taking the same time ! – samir Jan 18 '16 at 08:43
is it possible that using @property (strong, nonatomic) for instance has something related by this problem – samir Jan 18 '16 at 08:46

score 0 · Answer 3 · answered Jan 18 '16 at 08:12

This might be because pushing is executed in different thread. Try pushing the viewController in main thread. i.e.,replace your push controller code with

dispatch_async(dispatch_get_main_queue(), ^{
    UIStoryboard *mainStory = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    ListingViewController *listView = [mainStory instantiateViewControllerWithIdentifier:@"listing"];

    [self.navigationController pushViewController:listView animated:YES];
});

score 0 · Answer 4 · answered Jan 18 '16 at 10:45

0

Try to change in ListingViewController class viewDidLoad method to call async

- (void)viewDidLoad {
  [super viewDidLoad];

  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
  //move your code here
  // if you need to do something on ui (reload table view e.t.c) - call async in main thread
    dispatch_async(dispatch_get_main_queue(), ^{
      //Your UI code
    });
  });
}

answered Jan 18 '16 at 10:45

Sandr

189
9

the same result, nothing changed, its supposed to take an action directly after tapping on the button, but its freezing around 3 sec before taking this action !!!! – samir Jan 19 '16 at 07:08
Do you have something in viewWillDisappear ? – Sandr Jan 19 '16 at 07:11
It would be better if you show us your code, where you are calling web service. – Sandr Jan 19 '16 at 09:19
Dear, i've already commented all webservice calling methods, nothing Changed! I think its an allocating delay, am using the storyboard initiating with identifier to push VC B, but when i used allocating method: VC *B = [[VC alloc] init], then pushing to this view it works without delay, but the issue that i don't need to use the allocating method!! – samir Jan 19 '16 at 14:29

score 0 · Answer 5 · answered Jan 19 '16 at 16:20

0

You can use 'Instruments-Time Profiler', a developer tool with Xcode. It can check the time expense. Then, I think you will find you problem.

answered Jan 19 '16 at 16:20

Peike Luo

1
2

i dont think am able to understand its results, if u have any quick tutorial it would be great – samir Jan 20 '16 at 12:16
1. Open Xcode. 2. Choose Xcode > Open Developer Tool > Instruments. 3. Open Time Profiler. – Peike Luo Jan 21 '16 at 15:22

Navigating to ViewController containing ScrollView Going too Slow

5 Answers5