I have a UITableView which is populated by an array, I have a button on the navigaton bar which (when pressed) adds an item to the array and calls [self.tableView reloadData] in the UITableView. This results in numberOfRowsInSection being called and returning the correct number of rows (the number of items in the array) BUT doesn't call cellForRowAtIndexPath.
I have created a new navigation based application to try and find a solution but have exactly the same problem!
If anyone knows the answer it would be greatly appreciated, i've been tearing what's left of my hair out for the last day!
I have put the source for the test project up on my site at www.sofaracing.com/Downloads/Test3.zip
Works for me! ;)
In MainWindow.xib, You added an object Root View Controller (that's not part of the Navigation Controller) - Delete it, not necessary. Then connect outlet refreshFriendsList to the Bar Button of the NavigationItem of RootViewController. Wha-la, magic!
BTW: You may need to clean up the warning. And you might want to think about creating a class for your data model instead of using UIApplication sharedApplication.
I quickly debugged your test app. I couldnt't spot the root cause, but it seems that you have two different table views due some mess up in Interface Builder setup.
If you initialize original array with an item, cellForRowAtIndexPath is correctly called. If you examine self.tableView instance in this call and later in subsequent calls to refreshFriendsList, self.tableView points to a different instance.
2009-05-17 14:33:07.591 Test3[33580:20b] cellForRowAtIndexPath 0
2009-05-17 14:33:07.594 Test3[33580:20b] self.tableView: <UITableView: 0x52b9b0>
2009-05-17 14:42:36.810 Test3[33762:20b] numberOfRowsInSection: tableView <UITableView: 0x53bcd0>
Related
I have 5 view controllers, which are in a navigation controller hierarchy. When I reach my last view controller, there's a button that lets me go back to the "Home" view controller (named CardWalletViewController) which is a table view controller. Here's the method I have in my last VC (PointsResultsVC)
- (IBAction)homePressed:(id)sender {
NSArray *VCs = [self.navigationController viewControllers];
[self.navigationController popToViewController:[VCs objectAtIndex:0] animated:YES];
}
CardWalletVC's cells is being filled up by values coming from the saved instances of a Card in NSUserDefaults and it works fine.
Now, what I want is to update the value in my CardWalletViewController, which is the points of a card coming from my PointsResultsVC. Note that this points is saved in NSUserDefaults.
Upon the process of trying to update of the value shown in my CardWalletVC, I placed [self.tableView reloadData]; inside -viewDidLoad, -viewWillAppear, and -viewDidAppear of the said class. I tried placing it one by one in each of this methods, yet it doesn't seem to work.
Advice Please.
EDIT: problem solved
This one served as my guide Save data from one tab and reloadData in another tab.
And as I have discovered, -viewDidLoad of a certain class will only be called once, all throughout runtime of app. Whereas -viewWillAppear, it will be called every time the view appears.
So, I just moved the way I am loading the values saved in NSUserDefaults from -viewDidLoad to -viewWillAppear. Also, inside -viewWillAppear I placed the [self.tableView reloadData]. Then there, problem solved.
There's a lot of things that could be going wrong so you'll need to provide more info to narrow it down.
First of all, viewDidLoad will not be called so you can remove it from here. Both viewWillAppear and viewDidAppear will be called, so you only need it one of these 2 methods.
Next, you need to determine what the actual issue is.
1 - is self.tableView a proper reference to the table? Are you properly maintaining the reference?
2 - is the table actually reloading but using the old data, or is it not reloading at all? You can log the willDisplayCell method to see what is going on when the view appears.
With that info, the root cause can be narrowed down to a solvable problem.
I have an app that uses a UITablewView and in that TableView there is an NSMutableArray that holds the data to be displayed in the TabelView.
The problem is in my TableView Controller I use:
[[self tableView] reloadData]
To reload the TableView data and it works fine for a couple of times but doesn't work on the 3rd time and instead it changes the array count in a weird way.
Now I read similar question here and most likely I have 2 instances of the TableView or the TableViewController but I can't figure out how to troubleshoot this? How to detect if there are 2 instances of the object and fix that?
EDIT: Here is a pic how my navigation goes
So the 1st round of going from ScrollView to TableView things show up correctly. Then I go to UIView and back to TableView and it's working fine. So I go back all the way to ScrollView and back again to TableView and it's good.
But when I go to the UIView for this time then back to TableView this problem happens. TableView doesn't display the changes. So I put a breakpoint just before [[self tableView] reloadData] and found out that the array _displayedObjetcs gets its count changed. -1 actually. see the following screen shots b4 and after I step over the reloadData
and then
My immediate thought is that your array is not being retained properly, by your application. Your "weird" count is probably a number like 234791..., which is highly indicative of an array that has been released incorrectly. Therefore, I would check how your are retaining and releasing this array.
However, without more posted code, it is impossible to help you further.
I have an navigation-based app with three view controllers. The first has categories of information, the second has a list of items from that category and the third has detail on a specific item.
I populate view controllers 1 and 2 using an NSXMLParser which gets called on viewWillAppear. In the forward (VC1 to VC2 to VC3) direction, everything is fine, the parser gets called and the views are populated.
Unfortunately when the user chooses the back button on the navigation bar, the same process happens in reverse (VC3 to VC2 to VC1) as viewWillAppear is called again and so the parser is also called, even though it just fetches the same data.
I want to ensure that the parser is only called in the forward direction. Any ideas how I might structure this?
Thanks, Phil
Could you do something as simple as having a BOOL ivar called goingForward on VC2 that gets set to YES by VC1 prior to -pushViewController:animated: call and set to NO by VC3 prior to -popViewControllerAnimated: ... and then check goingForward in VC2's -viewWillAppear?
I am sure that there are more elegant ways of doing this (and look forward to reading about them) - but this should work, don't you think?
I am attempting to use NSKeyedArchiver to store the state of my UITabBarController. Inside the tabs are UINavigationControllers which contain UITableViewControllers.
The archiving appears to work without any problem.
When unarchiving I am running into strange problems with my UITableViewControllers. initWithCoder: is called correctly, and the first thing I am doing inside there is calling [super initWithCoder:]
The tableView appears to be correctly recreated, and has a delegate and dataSource property already set. If my initWithCoder: does nothing but call super and return self then my table view ends up empty and my delegate methods are not called. If I hookup the delegate and dataSource properties of self.tableView I see my content correctly, but didSelectRowAtIndexPath is not called upon selecting, and in one instance I am unable to scroll until the tableView is reloaded.
If in initWithCoder: I create a new UITableView everything works but I don't believe I should need to do this.
Am I doing something I shouldn't be in attempting this, or am I missing something obvious that I need to add to get things working correctly?
Update: setting self.tableView = [decoder decodeObjectForKey:#"tableView"] inside my controller seems to solve the scroll/select problem, but the resulting tableView is always UITableViewStylePlain and still seems like the wrong thing to do as the property is already set.
Your design pattern is certainly unusual. Normally, you wouldn't try to archive the table view, just the data used to create it. Then when you need the table view again, you would recreate it from those data, using the same code you used to create it in the first place.
I have a tab bar application which loads a UITableView when one of it's buttons are selected. It seems to load the view controller however it doesn't seem to be populating the data. I have tried setting the cell.text = #"cell" (while setting the number of rows > 0) and an NSLog in the CellForRowAtIndexPath proves that in fact the function is not being called. The same NSLog output to the console in the viewDidLoad function also generates no output so it seems as though its not getting called.
Any suggestions?
Try and call [tableView reloadData] from your -(void)viewWillAppear:(BOOL)animated; method. This should be called each time the user navigates to that tab and should set off the delegate callbacks that aren't currently being called. If they still aren't called make sure you have set the table delegate to self.
EDIT: Actually make sure you have set your table view's delegate and datasource to self;