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I'm trying to populate a simple uitableview in XCode 4.1.

Here is MessagesInbox.h:

#import <UIKit/UIKit.h> @interface MessagesInbox : UITableViewController <UITableViewDelegate,UITableViewDataSource>{ NSMutableArray *listData; IBOutlet UITableView *table; } @property (nonatomic,retain) UITableView *table; @property (nonatomic, retain) NSArray *listData; @end

Here is MessagesInbox.m:

#import "MessagesInbox.h" @implementation MessagesInbox @synthesize listData,table; - (void)loadView{ } - (id)initWithStyle:(UITableViewStyle)style { self = [super initWithStyle:style]; if (self) { // Custom initialization } return self; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } #pragma mark - View lifecycle - (void)viewDidLoad { [super viewDidLoad]; self.listData = [[NSArray alloc] initWithObjects:@"Red", @"Green", @"Blue", @"Indigo", @"Violet", nil]; } - (void)viewDidUnload { self.listData = nil; [super viewDidUnload]; // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; } - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; } - (void)viewDidDisappear:(BOOL)animated { [super viewDidDisappear:animated]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationPortrait); } #pragma mark - Table view data source - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 0; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{ return [self.listData count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } // Configure the cell... cell.textLabel.text = [listData objectAtIndex:indexPath.row]; return cell; } /* // Override to support conditional editing of the table view. - (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath { // Return NO if you do not want the specified item to be editable. return YES; } */ /* // Override to support editing the table view. - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { if (editingStyle == UITableViewCellEditingStyleDelete) { // Delete the row from the data source [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; } else if (editingStyle == UITableViewCellEditingStyleInsert) { // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view } } */ /* // Override to support rearranging the table view. - (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath { } */ /* // Override to support conditional rearranging of the table view. - (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath { // Return NO if you do not want the item to be re-orderable. return YES; } */ #pragma mark - Table view delegate - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Navigation logic may go here. Create and push another view controller. /* <#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil]; // ... // Pass the selected object to the new view controller. [self.navigationController pushViewController:detailViewController animated:YES]; [detailViewController release]; */ } - (void)dealloc { [listData release]; [super dealloc]; } @end

No matter what I do, I keep getting a white screen...

I've connected the tableview's delegate and datasource to file's owner.

Any help greatly appreciated,

Edit-------------------

Here are my connections:

enter image description here

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4
  • What is the count of listData when numberOfRowsInSection is called? Is cellForRowAtIndexPath ever called? Commented Sep 20, 2011 at 19:06
  • Just a note, if your controller is a UITableViewController then you do not need to implement the UITableView protocols. Commented Sep 20, 2011 at 19:07
  • I'm using a UINavigationController. What effect does this have? Commented Sep 20, 2011 at 19:10
  • Your UITableView should belong to a UITableViewController. That controller in turns should be pushed onto your UINavigationController stack. Commented Sep 20, 2011 at 19:13

5 Answers 5

Reset to default
5

You're returning zero sections - you should have at least one.

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; }
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4 Comments

A white screen or a screen with an empty table view (some horizontal lines)? Show me the code where you're adding the view controller's view to your window or whatever.
A white screen (with the navigation bar and back button on top)... No lines whatsoever
I cannot see where your UITableView would get connected to the one you're referencing in your controller. Plus there is an empty loadView: - where would the UITableView come from?
Hooray! Just don't forget the other issue with the 0 sections! :-)
3

You're returning 0 as the number of sections! You should return at least 1 section if you want to display any table data.

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2

You're overriding the -loadView method, which prevents your base class (UITableViewController) from loading the actual UITableView.

Remove that method and you'll see your table view.

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1

I see two strange things here:

[1] sections returned are 0; you must define at least 1 section to work

[2] you're using another table on top of the "tableView" property defined by the UITableViewController class. You must check if this two tables are not conflicting in some way (sincerely I never tried to put another table over the "standard" table of the controller). Just do this extra check other than the solution at [1].

This is a snapshot from Apple docs as reference:

If a nib file is specified via the initWithNibName:bundle: method (which is declared by the superclass UIViewController), UITableViewController loads the table view archived in the nib file. Otherwise, it creates an unconfigured UITableView object with the correct dimensions and autoresize mask. You can access this view through the tableView property. If a nib file containing the table view is loaded, the data source and delegate become those objects defined in the nib file (if any). If no nib file is specified or if the nib file defines no data source or delegate, UITableViewController sets the data source and the delegate of the table view to self. When the table view is about to appear the first time it’s loaded, the table-view controller reloads the table view’s data. It also clears its selection (with or without animation, depending on the request) every time the table view is displayed. The UITableViewController class implements this in the superclass method viewWillAppear:. You can disable this behavior by changing the value in the clearsSelectionOnViewWillAppear property. When the table view has appeared, the controller flashes the table view’s scroll indicators. The UITableViewController class implements this in the superclass method viewDidAppear:. It implements the superclass method setEditing:animated: so that if a user taps an Edit|Done button in the navigation bar, the controller toggles the edit mode of the table. You create a custom subclass of UITableViewController for each table view that you want to manage. When you initialize the controller in initWithStyle:, you must specify the style of the table view (plain or grouped) that the controller is to manage. Because the initially created table view is without table dimensions (that is, number of sections and number of rows per section) or content, the table view’s data source and delegate—that is, the UITableViewController object itself—must provide the table dimensions, the cell content, and any desired configurations (as usual). You may override loadView or any other superclass method, but if you do be sure to invoke the superclass implementation of the method, usually as the first method call.

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0

The other answers are correct.

  1. You shouldn't override loadView w/o calling [super loadView].

  2. You need to return > 0 for the number of sections in numberOfSectionsInTableView. You should need your iVar table. The tableView iVar is defined by UITableViewController.

  3. You also have a memory leak where you alloc listData.

    self.listData = [[NSArray alloc] initWithObjects:@"Red", @"Green", @"Blue", @"Indigo", @"Violet", nil];

The code above will retain the array twice. You should change to one of:

self.listData = [NSArray arrayWithObjects:@"Red", @"Green", @"Blue", @"Indigo", @"Violet", nil];

or

listData = [[NSArray alloc] initWithObjects:@"Red", @"Green", @"Blue", @"Indigo", @"Violet", nil];

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2 Comments

according to the documentation you should not call [super loadView]
From the UITableViewController docs. You may override loadView or any other superclass method, but if you do be sure to invoke the superclass implementation of the method, usually as the first method call.

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