Question

I have a class with a tableView. I get no build errors, but when I try to run the app, after I add a new item, nothing appears to happen. Here’s the code:

In .h

@interface entriesViewController : UIViewController <UITableViewDelegate>

@property (weak, nonatomic) IBOutlet UITableView *TableView;


-(IBAction)startEditing:(id)sender;
-(IBAction)newItem:(id)sender;
@end

In .m

#import "entriesViewController.h"
#import "LEItemStore.h"
#import "LEItem.h"

@interface entriesViewController ()

@end

@implementation entriesViewController
@synthesize TableView;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
        [TableView setDelegate:self];
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    [TableView reloadData];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


-(IBAction)startEditing:(id)sender {

    if ([TableView isEditing])
    {
        [TableView setEditing:NO animated:YES];


    }
    else
    {
        [TableView setEditing:YES animated:YES];
    }
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [[[LEItemStore sharedStore] allItems] count];
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UITableViewCell"];

    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"UITableViewCell"];
    }

    LEItem *p = [[[LEItemStore sharedStore] allItems]objectAtIndex:[indexPath row]];

    [[cell textLabel] setText:[p description]];

    return cell;
}

-(IBAction)newItem:(id)sender {
    LEItem *newItem = [[LEItemStore sharedStore] createItem];
    [TableView reloadData];
}


-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete)
    {
        LEItemStore *ps = [LEItemStore sharedStore];
        NSArray *items = [ps allItems];
        LEItem *p = [items objectAtIndex:[indexPath row]];
        [ps removeItem:p];

        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
    }
}

-(void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
    [[LEItemStore sharedStore] moveItemAtIndex:[sourceIndexPath row] toIndex:[destinationIndexPath row]];
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{


    //NSArray *items = [[LEItemStore sharedStore] allItems];
    //BNRItem *selectedItem = [items objectAtIndex:[indexPath row]];
}

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [[self TableView]reloadData];
}

It would appear as if the TableView isn’t reloading it’s data. By the way, all connections have been made. Absolutely nothing appears. Just my Toolbar, the TableView does not change even after I added an item.

Answer 1

Ok so after clearing this in the comments, your problem is that you haven’t set the data source (you can also do this with an array controller).
So you set the delegate and the data source:

[TableView setDelegate:self];
[TableView setdataSource: self];

Then you declare the class to also implement the UITableViewDataSource protocol.
And you provide the two fondamental methods (also optional methods are welcome):

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section;

This is an example of a simple data source implementation that just has one label saying hello:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell* cell=[[UITableViewCell alloc]init];
    UILabel* label= cell.textLabel;
    label.text= @"Hello";
    return cell;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 1;
}

But now you know how to provide a more complex data source: if you have an array you can read the index path and then set the label using the objectAtIndex method.