Cells disappear when scroll down in my UITableView - ios

Question

When I scroll down in my tableView some contents of cells disappear (labels and imageViews).
My code:
-(void)viewWillAppear:(BOOL)animated{
[comentarios removeAllObjects];
NSString *lookup=[NSString stringWithFormat:#"http://my.url"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:lookup]];
[request setHTTPMethod:#"GET"];
NSError *error = nil; NSURLResponse *response = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSMutableArray *jsonDict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
NSLog(#"%#",jsonDict);
for (int i=0; i<[jsonDict count]; i++) {
Comentario *come=[[Comentario alloc] init];
come.nick=[[jsonDict objectAtIndex:i] objectForKey:#"nick"];
come.comment=[[jsonDict objectAtIndex:i] objectForKey:#"content"];
come.avatar=[[jsonDict objectAtIndex:i] objectForKey:#"color"];
[comentarios addObject:come];
}
[self reloadInputViews];
[self.comentariosTableView reloadData];
}
and
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
if( cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier: CellIdentifier];
}
// Display recipe in the table cell
UIImageView *avatar = (UIImageView *)[cell viewWithTag:100];
avatar.image = [UIImage imageNamed:[[comentarios objectAtIndex:indexPath.row] avatar]];
UILabel *nick = (UILabel *)[cell viewWithTag:101];
nick.text =[[comentarios objectAtIndex:indexPath.row] nick];
UILabel *comment = (UILabel *)[cell viewWithTag:102];
comment.text = [[comentarios objectAtIndex:indexPath.row] comment];
UIButton *sinvoto = (UIButton *)[cell viewWithTag:103];
UIButton *ticket = (UIButton *)[cell viewWithTag:104];
return cell;
}
I can't see the mistake, please help me.
Thank you in advance
EDIT Nª1
just changed this
ViewController.m
#import "ViewController.h"
#import "SimpleTableCell.h"
#interface ViewController (){
NSMutableArray *comentarios;
}
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.comenatrioTableView.delegate=self;
self.comenatrioTableView.dataSource=self;
self.automaticallyAdjustsScrollViewInsets = NO;
UIImage *plus=[[UIImage imageNamed:#"megafono.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc] initWithImage:plus style:UIBarButtonItemStylePlain target:self action:#selector(comenta:)];
self.navigationController.navigationBar.barTintColor=[UIColor colorWithRed:204.0/255.0 green:0.0/255.0 blue:00.0/255.0 alpha:1.0f];
comentarios=[[NSMutableArray alloc] init];
[self reloadInputViews];
}
-(void)viewWillAppear:(BOOL)animated{
[comentarios removeAllObjects];
NSString *lookup=[NSString stringWithFormat:#"http://myURL"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:lookup]];
[request setHTTPMethod:#"GET"];
NSError *error = nil; NSURLResponse *response = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSMutableArray *jsonDict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
NSLog(#"%#",jsonDict);
for (int i=0; i<[jsonDict count]; i++) {
Comentario *come=[[Comentario alloc] init];
come.nick=[[jsonDict objectAtIndex:i] objectForKey:#"nick"];
come.comment=[[jsonDict objectAtIndex:i] objectForKey:#"content"];
come.avatar=[[jsonDict objectAtIndex:i] objectForKey:#"color"];
[comentarios addObject:come];
}
[self reloadInputViews];
}
-(void)viewDidAppear:(BOOL)animated{
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return [comentarios count];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 110;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = #"SimpleTableCell";
SimpleTableCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier forIndexPath:indexPath];
Comentario *comentario=[[Comentario alloc] init];
comentario =[comentarios objectAtIndex:indexPath.row];
cell.avatar.image=[UIImage imageNamed:[comentario avatar]];
cell.nick.text=[comentario nick];
cell.comment.text =[comentario comment];
return cell;
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
-(void)comenta:(id)sender{
[self performSegueWithIdentifier:#"goComment" sender:self];
}
#end
and ViewController.h
#import <UIKit/UIKit.h>
#import "Comentario.h"
#interface ViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>
#property (weak, nonatomic) IBOutlet UITableView *comenatrioTableView;
#end
Edit Nª3
The proble is when I scroll down, the information of cells become nil but comentarios Array have the information.
Edit Nª4
here is the project https://github.com/QuimeraKoke/BANG-

Answer 1

I have a couple of other suggestions that will improve your code.
You have to call super in viewDidAppear and viewWillAppear methods:
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:YES];
}
Instead of using:
Comentario *comentario = [[Comentario alloc] init];
comentario = [comentarios objectAtIndex:indexPath.row];
with:
Comentario *comentario = [comentarios objectAtIndex:indexPath.row];
Finally, you should check your dataSource:
for (int i=0; i<[jsonDict count]; i++) {
Comentario *come = [[Comentario alloc] init];
come.nick = [[jsonDict objectAtIndex:i] objectForKey:#"nick"];
come.comment = [[jsonDict objectAtIndex:i] objectForKey:#"content"];
come.avatar = [[jsonDict objectAtIndex:i] objectForKey:#"color"];
[comentarios addObject:come];
NSLog(#"nick = %#, comment = %#, avatar = %#", come.nick, come.comment, come.avatar);
}
EDIT:
Instead of using:
#interface Comentario : NSObject
#property (weak,nonatomic) NSString *nick;
#property (weak,nonatomic) NSString *comment;
#property (weak,nonatomic) NSString *avatar;
#end
you should use:
#interface Comentario : NSObject
#property (copy,nonatomic) NSString *nick;
#property (copy,nonatomic) NSString *comment;
#property (copy,nonatomic) NSString *avatar;
#en
Your problem has been resolved.
Copy
copy is required when the object is mutable. Use this if you need the
value of the object as it is at this moment, and you don't want that
value to reflect any changes made by other owners of the object. You
will need to release the object when you are finished with it because
you are retaining the copy.
Weak
weak is similar to strong except that it won't increase the reference
count by 1. It does not become an owner of that object but just holds
a reference to it. If the object's reference count drops to 0, even
though you may still be pointing to it here, it will be deallocated
from memory.
This is a good website to learn about strong and weak for iOS 5.
http://www.raywenderlich.com/5677/beginning-arc-in-ios-5-part-1
In addition to the above problem，your constrains of the SimpleTableCell is also incorrect:
You should go to the Main.storyboard and check it.(In Interface Builder Select the Compact Width and Compact Height Size Class)

Answer 2

The tableView:cellForRowAtIndexPath: code you're using is pretty old.
I'd suggest creating a custom UITableViewCell class, with properties for your labels, image, and buttons.
#interface MyTableViewCell : UITableViewCell
#property (nonatomic, weak) IBOutlet UILabel *nick;
#property (nonatomic, weak) IBOutlet UILabel *comment;
#property (nonatomic, weak) IBOutlet UIImageView *avatar;
#property (nonatomic, weak) IBOutlet UIButton *sinvoto;
#property (nonatomic, weak) IBOutlet UIButton *ticket;
#end
In your storyboard, set that cell's class to your custom tableViewCell, and connect its IBOutlets to the storyboard cell's labels, image, and buttons. This will eliminate having to use tags.
Change the dequeueReusableCellWithIdentifier: call to:
MyTableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
This will always return a cell, so you will never have to check for nil.
Now you can directly set the cell's properties:
cell.avatar.image = [UIImage imageNamed:[[comentarios objectAtIndex:indexPath.row] avatar]];
cell.nick.text =[[comentarios objectAtIndex:indexPath.row] nick];
cell.comment.text = [[comentarios objectAtIndex:indexPath.row] comment];
Update:
This line (has to do with changing the keyboard) is unnecessary and can be removed:
[self reloadInputViews];
Is there a reason why you are using a UIViewController (with a tableView that you added), instead of simply using a UITableViewController?
The UITableViewController knows how to adjust its insets to account for top and bottom bars (and you would set its automaticallyAdjustsScrollViewInsets to YES).
After making the changes that Banning suggests, you may be ok. I can't see any other reason why the cells would be blank after scrolling.
If it's still happening, you should post your Comentario class, so we can see if an issue with that code is affecting the stored data.