I receive data async via a completion method.
When the completion get fired, I passing the data to a new tableviewcontroller.
But the table view controller takes too much time to load. The data is an array with up to 25 objects. So not that much.
To move to the new controller, I use a segue I created in storyboard.
This is the completion method:
{
if(receivedArray != nil)
{
searchResult = receivedArray;
[self performSegueWithIdentifier:#"searchToDisplay" sender:self];
}
}
When I debug, and set a breakpoint to the prepareForSegue:sender: method, I get there after less than one second.
here the method:
if([segue.identifier isEqualToString:#"searchToDisplay"])
{
BookingDisplayTableViewController *bookingVC = (BookingDisplayTableViewController *)segue.destinationViewController;
bookingVC.bookings = [NSArray arrayWithArray:searchResult];
}
Additionally here the viewDidLoad method of the BookingDisplayController. The viewWillAppear isn't overrided.
- (void)viewDidLoad
{
[super viewDidLoad];
UINib *nib = [UINib nibWithNibName:#"BookingCellDesign" bundle:nil];
[self.tableView registerNib:nib forCellReuseIdentifier:#"BookingCell"];
self.tableView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"tableBackground.png"]];
self.clearsSelectionOnViewWillAppear = NO;
}
And I can't get the performance problem here...
I need help. :)
Thanks!
UPDATE
So i troubleshooted the problem. It was the completion method.
I got the date via dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)... And a synchronous NSMutableRequest.
I fired the completion After I send the synchronous request. Now I put this code inside the dispath block
dispatch_async(dispatch_get_main_queue(),
^{
if(response)
{
[self removeLoadingView];
if(bookingTemp.count > 0)
completion(bookingTemp);
else
completion(nil);
}
});
And now it works great.
What I don't understand before I did this, I debugged and reached the completion block like now. But only the segue didn't start.
Thanks for help!
Related
So i am showing a model controller on top of a view controller. And i have texts in the model controller, but somehow the texts are not visible. I tried everything but somehow labels are not visible. But of you stay on the page for like 30 -40 sec the text shows up. Also this model controller is called from main view controller after a successful service(REST) call. If i call the model without making the service call then labels are visible in simulator/iPad both. But if i call it after service call inside success block then labels are not visible. I tried adding the text programmatically but still same issue. I tried debugging using Color blended layers, but the label is not at all visible in the view somehow. :(
[self.serviceManager getCustDetails:account successBlock:^(NSDictionary * successDict) {
[self hideLoadingAnimation];
NSDictionary *custData = [[successDict objectForKey:#"txnData"] objectForKey:#"custData"];
self.showCurrYear = [iraContribData objectForKey:#"showCurrYear"];
if ([self.showCurrYear isEqual: #"true"]){
[self performSegueWithIdentifier:#"CSegue" sender:self];
}
} failureBlock:^(NSDictionary * failureDict) {
[self hideLoadingAnimation];
NSLog(#"Failiure Dict %#",failureDict);
}];
And this prepareForSegue method, -
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"CSegue"]) {
CustViewController *cVC = segue.destinationViewController;
cVC.delegate = self;
[cVC setModalPresentationStyle:UIModalPresentationFormSheet];
cVC.preferredContentSize = CGSizeMake(800,750);
}
}
Below is my screen in storyboard, but in simulator the label is not visible, only continue and close button is visible.
Please help!, any suggestions are most welcome. Thanks!
It is possible that the delay is due to a user interface update not made on the main thread.
Try to make sure that your code is executed on the main thread using dispatch_async like this :
[self.serviceManager getCustDetails:account successBlock:^(NSDictionary * successDict) {
dispatch_async(dispatch_get_main_queue(), ^{
[self hideLoadingAnimation];
NSDictionary *custData = [[successDict objectForKey:#"txnData"] objectForKey:#"custData"];
self.showCurrYear = [iraContribData objectForKey:#"showCurrYear"];
if ([self.showCurrYear isEqualToString:#"true"]){
[self performSegueWithIdentifier:#"CSegue" sender:self];
}
});
} failureBlock:^(NSDictionary * failureDict) {
dispatch_async(dispatch_get_main_queue(), ^{
[self hideLoadingAnimation];
NSLog(#"Failiure Dict %#",failureDict);
});
}];
When I give a good swipe to my tableView and press the "Back" button before the tableView ended it's scrolling, my app crashes. I've tried the following:
- (void) closeViewController
{
[self killScroll];
[self.navigationController popToRootViewControllerAnimated:YES];
[self dismissViewControllerAnimated:YES completion:nil];
}
- (void)killScroll
{
CGPoint offset = sellersTableView.contentOffset;
[sellersTableView setContentOffset:offset animated:NO];
}
That didn't work, same crash. I don't see why, the error I'm getting is the following:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:'
So that means that the tableView is still requesting a cell when everything is already being deallocated. Makes no sense.
Then I tried this:
- (void) closeViewController
{
[self.navigationController popToRootViewControllerAnimated:YES];
[self dismissViewControllerAnimated:YES completion:nil];
}
- (void)dealloc
{
sellersTableView.dataSource = nil;
sellersTableView.delegate = nil;
sellersTableView = nil;
}
Gives me the same error. Any ideas?
Update:
My delegate methods
creation
if (textField == addSellerTextField) {
sellersTableView = [[UITableView alloc] initWithFrame:CGRectMake(addSellerTextField.frame.origin.x + addSellerTextField.frame.size.width + 10, addSellerTextField.frame.origin.y - [self heightForTableView] + 35, 200, [self heightForTableView])];
sellersTableView.delegate = self;
sellersTableView.dataSource = self;
sellersTableView.backgroundColor = [[UIColor grayColor] colorWithAlphaComponent:0.05];
sellersTableView.separatorColor = [[UIColor grayColor] colorWithAlphaComponent:0.15];
sellersTableView.rowHeight = 44;
sellersTableView.layer.opacity = 0;
[self.companyView addSubview:sellersTableView];
[UIView animateWithDuration:0.3 delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{sellersTableView.layer.opacity = 1;} completion:nil];
}
cellForRowAtIndexPath
if (tableView == sellersTableView) {
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.backgroundColor = [UIColor clearColor];
if ([sellersArray count] > 0) {
cell.textLabel.text = [sellersArray objectAtIndex:indexPath.row];
} else {
UILabel *noSellersYetLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, sellersTableView.frame.size.width, [self heightForTableView])];
noSellersYetLabel.text = #"no sellers yet";
noSellersYetLabel.textAlignment = NSTextAlignmentCenter;
noSellersYetLabel.textColor = [UIColor grayColor];
[cell addSubview:noSellersYetLabel];
sellersTableView.separatorStyle = UITableViewCellSeparatorStyleNone;
}
}
removing
- (void) textFieldDidEndEditing:(UITextField *)textField
{
if (textField == addSellerTextField) {
[self updateSellers:textField];
}
}
- (void)updateSellers:(UITextField *)textField
{
[textField resignFirstResponder];
[self hideSellersTableView];
}
- (void)hideSellersTableView
{
[UIView animateWithDuration:0.3 delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{sellersTableView.layer.opacity = 0;} completion:nil];
sellersTableView.dataSource = nil;
sellersTableView.delegate = nil;
[sellersTableView removeFromSuperview];
sellersTableView = nil;
}
Solution
So apparently putting the dataSource = nil and delegate = nil into textFieldDidEndEditing fixed the problem. Thanks everybody for the answers!
It's strange behaviour of UITableView. The easiest way to resolve this issue just set the dataSource and delegate property of UITAbleView to nil before you make a call of function popToRootViewControllerAnimated. Furthermore you can use more common solution and add the code that set the properties to nil into the -dealloc method. In addition you no need the -killScroll method.
After a short research I have realized what the problem is. This unusual behaviour appeared in iOS 7. The scroll view retained by its superview may send message to delegate after the delegate is released. It happens due to -removeFromSuperview implementation UIScrollView triggers -setContentOffset: and, eventually, send message to delegate.
Just add following lines at the beginning of dealloc method:
sellersTableView.delegate = nil;
sellersTableView.dataSource = nil;
No need to use hacks like your killScroll method.
Also, I can't see why you want to call both popToRootViewController and dismissViewController.
If you dismiss a view controller which is embedded in a navigation controller, navigation controller itself as well as all contained view controllers will be released.
In your case you'll have just weird animation.
setContentOffset method won't help you, try to set
sellersTableView.dataSource = nil;
somewhere in your viewWillDisappear method.
This is not a good practice of course.
Change you closeViewController like below and see if works
(void) closeViewController
{
sellersTableView.dataSource = nil;
sellersTableView.delegate = nil;
[self.navigationController popToRootViewControllerAnimated:YES];
[self dismissViewControllerAnimated:YES completion:nil];
}
I don't think that setting the tableView (or it's delegate) to nil is the issue. You should be able to perform both dismissViewControllerAnimated or popToRootViewController individually without having to modify the tableView in this way.
So the issue is most likely due to calling both of these methods at the same time (and with animated = YES), and in doing so asking your viewController setup to do something unnatural.
Looks like upon tapping a "close" button you are both popping to a rootViewController of a UINavigationController, as well as dismissing a modal viewController.
In doing so, you're dismissing a modal viewController which is likely presented by the topViewController of the navigationController (so top vc is holding a reference to modal vc). AND you're trying to kill the top vc via the popToRootViewController method call. And you're doing both of these things using animated = YES, which means they take some time to complete, and you can't be sure when each finishes (ie you can't be sure when dealloc will be called).
Depending on your needs you could do one of several things.
Consider adding a delegate property to your modal vc. Dismiss the modal vc, and in the completionBlock of the modal vc tell its delegate that it's finished dismissing. At that point call popToRootViewController (because at this point you can be sure that the modal is gone and scrolling wasn't interrupted).
If it's your navController that's been presented modally, then do this in the opposite order. Notifying the delegate that the pop operation has completed, and do the modal dismissal then.
I am developing an app where the user will get to confirm some action via UIAlertView, if he confirms, I call a method that handles the operation, then I prepare to pop the view I am in to go back to another view after the method has been called.
I want to show UIActivityIndicatorView if the user presses confirm for as long as it takes to execute the method and go to that other view. I used startAnimating and stopAnimating in the proper location, but i never get to see the UI UIActivityIndicatorView shown, not for a sec.
I guess its related to some UI issues due to UIAlertView, not sure if I am correct though. I just need a clue on how to use UIActivityIndicatorView properly for a method execution time.
My code:
- (void)viewDidLoad
{
[super viewDidLoad];
self.activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
self.activityIndicator.alpha = 1.0;
self.activityIndicator.hidesWhenStopped = YES;
self.activityIndicator.center = self.view.center;
[self.view addSubview:self.activityIndicator];
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if(buttonIndex == 1) {
[self.activityIndicator startAnimating];
ContactsTableViewController *contactTableView = [self getContactsTVC];
[contactTableView applyActionOnCells];
// doing some setup before poping off to the root view controller of my nav controller
[self.activityIndicator stopAnimating];
// then go to rootViewController
[self.navigationController popToRootViewControllerAnimated:YES];
}
}
I'm not 100% certain, but try to comment out the stopAnimating call and see if it shows up.
If that helps, applyActionOnCells probably blocks your main thread (where all UI stuff also happens) and the indicator never has a chance to show up before you hide it again.
In that case, try do the applyActionOnCells call in the background:
if(buttonIndex == 1) {
[self.activityIndicator startAnimating];
__block typeof(self) bself = self;
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
ContactsTableViewController *contactTableView = [bself getContactsTVC];
[contactTableView applyActionOnCells];
dispatch_async(dispatch_get_main_queue(), ^{
[bself.activityIndicator stopAnimating];
// then go to rootViewController
[bself.navigationController popToRootViewControllerAnimated:YES];
});
});
}
Edit: see also an earlier question.
I am using setNeedsDisplay on my GUI, but there update is sometimes not done. I am using UIPageControllView, each page has UIScrollView with UIView inside.
I have the following pipeline:
1) application comes from background - called applicationWillEnterForeground
2) start data download from server
2.1) after data download is finished, trigger selector
3) use dispatch_async with dispatch_get_main_queue() to fill labels, images etc. with new data
3.1) call setNeedsDisplay on view (also tried on scroll view and page controller)
Problem is, that step 3.1 is called, but changes apper only from time to time. If I swap pages, the refresh is done and I can see new data (so download works correctly). But without manual page turn, there is no update.
Any help ?
Edit: code from step 3 and 3.1 (removed _needRefresh variables pointed in comments)
-(void)FillData {
dispatch_async(dispatch_get_main_queue(), ^{
NSString *stateID = [DataManager ConvertStateToStringFromID:_activeCity.actual_weather.state];
if ([_activeCity.actual_weather.is_night boolValue] == YES)
{
self.contentBgImage.image = [UIImage imageNamed:[NSString stringWithFormat:#"bg_%#_noc", [_bgs objectForKey:stateID]]];
if (_isNight == NO)
{
_bgTransparencyInited = NO;
}
_isNight = YES;
}
else
{
self.contentBgImage.image = [UIImage imageNamed:[NSString stringWithFormat:#"bg_%#", [_bgs objectForKey:stateID]]];
if (_isNight == YES)
{
_bgTransparencyInited = NO;
}
_isNight = NO;
}
[self.contentBgImage setNeedsDisplay]; //refresh background image
[self CreateBackgroundTransparency]; //create transparent background if colors changed - only from time to time
self.contentView.parentController = self;
[self.contentView FillData]; //Fill UIView with data - set labels texts to new ones
//_needRefresh is set to YES after application comes from background
[self.contentView setNeedsDisplay]; //This do nothing ?
[_grad display]; //refresh gradient
});
}
And here is selector called after data download (in MainViewController)
-(void)FinishDownload:(NSNotification *)notification
{
dispatch_async(dispatch_get_main_queue(), ^{
[_activeViewController FillData]; //call method shown before
//try call some more refresh - also useless
[self.pageControl setNeedsDisplay];
//[self reloadInputViews];
[self.view setNeedsDisplay];
});
}
In AppDelegate I have this for application comes from background:
-(void)applicationWillEnterForeground:(UIApplication *)application
{
MainViewController *main = (MainViewController *)[(SWRevealViewController *)self.window.rootViewController frontViewController];
[main UpdateData];
}
In MainViewController
-(void)UpdateData
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(FinishForecastDownload:) name:#"FinishDownload" object:nil]; //create selector
[[DataManager SharedManager] DownloadForecastDataWithAfterSelector:#"FinishDownload"]; //trigger download
}
try this:
[self.view performSelectorOnMainThread:#selector(setNeedsLayout) withObject:nil waitUntilDone:NO];
or check this link:
http://blackpixel.com/blog/2013/11/performselectoronmainthread-vs-dispatch-async.html
setNeedsDisplay triggers drawRect: and is used to "redraw the pixels" of the view , not to configure the view or its subviews.
You could override drawRect: and modify your labels, etc. there but that's not what it is made for and neither setNeedsLayout/layoutSubviews is.
You should create your own updateUI method where you use your fresh data to update the UI and not rely on specialized system calls meant for redrawing pixels (setNeedsDisplay) or adjusting subviews' frames (drawRect:).
You should set all your label.text's, imageView.image's, etc in the updateUI method. Also it is a good idea to try to only set those values through this method and not directly from any method.
None of proposed solutions worked. So at the end, I have simply remove currently showed screen from UIPageControllView and add this screen again. Something like changing the page there and back again programatically.
Its a bit slower, but works fine.
I created a method that sets the title of a button based on a value.
This method needs to be called when opening the viewController and maybe refreshed when the controller appears again.
So i created the method and I called that method in viewDidLoad and viewDidApper but it seems to be called only when I change page and turn back to the view controller.
Why?
My code is
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
[self controlloRichieste];
......
}
-(void)viewDidAppear:(BOOL)animated{
[self controlloRichieste];
}
-(void)controlloRichieste{
//Numero richieste di contatto
NSString *numeroRichieste = #"1";
if([numeroRichieste isEqual:#"0"]){
[_labelRequestNumber setTitle:#"Nessuna" forState:UIControlStateNormal];
} else {
_labelRequestNumber.titleLabel.text = numeroRichieste;
_labelRequestNumber.tintColor = [UIColor redColor];
}
//Fine Numero richieste di contatto
}
You can also move that code to viewWillAppear so that it gets called each time it appears.
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self controlloRichieste];
}
I see the problem now, try the other way around
-(void)controlloRichieste{
//Numero richieste di contatto
NSString *numeroRichieste = #"1";
if([numeroRichieste isEqual:#"0"]){
[_labelRequestNumber setTitle:#"Nessuna" forState:UIControlStateNormal];
} else {
_labelRequestNumber.tintColor = [UIColor redColor];
[[_labelRequestNumber titleLabel]setText:numeroRichieste];
}
//Fine Numero richieste di contatto
}
Change set the button color, before you change its titleLabel's text
I created a demo PROJECT for you, hope it's helpful!
When you open view first time the viewDidLoad is called and the viewDidAppeare.
The viewDidAppeare is called every time when the view is opened, when you push or present other view controller and go back to the maine one viewDidAppeare is called.
You should call:
[super viewDidAppear:animated];
The viewDidLoad is called just when the view is loaded and after that when it's deallocated and it needs to be allocated again. So mostly when you push or present other view controller and go back to the maine one viewDidLoad is not called.