Cell image only appearing after scrolling - iphone

Question

I have a UITableView with method cellForRowAtIndexPath shown below, the problem is that cellImage only appears after having scrolled completely up (so no rows are visible) and then releasing. The strange thing is that I have identical code in another class for a separate table view and the image appears fine. Any ideas?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryNone;
}
[cell.textLabel setText:[items objectAtIndex:indexPath.row]];
[cell.textLabel setFont:[UIFont fontWithName:#"Helvetica" size:15.0f]];
[cell.textLabel setTextColor:[UIColor whiteColor]];
[cell setBackgroundColor:[[UIColor alloc] initWithRed:117.0/255.0 green:118.0/255.0 blue:121.0/255.0 alpha:1.0]];
[self.tableView setBackgroundView:nil];
[self.tableView setBackgroundView:[[UIView alloc] init]];
[self.view setBackgroundColor:[[UIColor alloc] initWithRed:167.0/255.0 green:169.0/255.0 blue:172.0/255.0 alpha:1.0]];
UIImageView *cellImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"next#2x.png"]];
[cell addSubview:cellImage];
[cellImage setFrame:CGRectMake(0, 0, 26, 24)];
[cellImage setCenter:CGPointMake(cell.frame.size.width - 30, cell.frame.size.height/2)];
return cell;
}

Answer 1

[self.tableView setBackgroundView:nil];
[self.tableView setBackgroundView:[[UIView alloc] init]];
The lines dont belong to the method. You call the methods every time you scroll for every cell. Put them in your viewDidLoad method, after you have created your table view.
UIImageView *cellImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"next#2x.png"]];
[cell addSubview:cellImage];
These lines are really very BAD and may cause a memory leak.
Everytime you scroll the table view you add a imageview to the cell. Table view reuses the cells. It means when cell is reused, you add a new imageview to the cell. After you scroll more times you have x times imageview on every cell, unless you remove them somewhere in you code.
Other point is, if you want to add some subview to a cell (eg. in init method of the cell) then add it to contenview of the cell like this
[cell.contentView addSubview:someView];
Otherwise your subview may overlap accessory views. And you can have problems when your cell is resized.
I advise you read the guide from the following link:
http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/tableview_iphone/TableViewCells/TableViewCells.html#//apple_ref/doc/uid/TP40007451-CH7-SW1

Answer 2

As captured in many of the comments, there are a number of issues:
Set your view and tableView background in your viewDidLoad method (or via your XIB), not in cellForRowAtIndexPath
Use the cell.imageView property to set a left icon, OR, alternatively, to build a custom cell you would use [cell.contentView addSubview:cellImage]. If you do the latter, you should also add your textLabel in the same manner as a UILabel.
To set the background of a tableview cell, use this delegate method:
-(void) tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell*)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
[cell setBackgroundColor:[[UIColor alloc] initWithRed:117.0/255.0 green:118.0/255.0 blue:121.0/255.0 alpha:1.0]];
}
though for efficiency you should instantiate this UIColor once in your viewcontroller and set it as [cell setBackgroundColor:self.cellBackground];

Answer 3

The problem you are facing is due to reuseIdentifier for cell.
Also you are creating Imageview everytime cellForRowAtIndexPath is executed.
i will suggest two solution here for you.
1st Option :- just replace this code :
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
cell.accessoryType = UITableViewCellAccessoryNone;
}
this is not proper way when you are dealing with dynamic images, means you are downloading thumbnail from server and data content is more, if it's small and static data then it's fine for you.
2nd Option :- just use this formatted code this will not create imageview everytime just use object from current cell with tag.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryNone;
UIImageView *cellImage = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 26, 24)];
cellImage.tag = 88;
[cell addSubview:cellImage];
[cellImage setCenter:CGPointMake(cell.frame.size.width - 30, cell.frame.size.height/2)];
}
[cell.textLabel setText:[items objectAtIndex:indexPath.row]];
[cell.textLabel setFont:[UIFont fontWithName:#"Helvetica" size:15.0f]];
[cell.textLabel setTextColor:[UIColor whiteColor]];
[cell setBackgroundColor:[[UIColor alloc] initWithRed:117.0/255.0 green:118.0/255.0 blue:121.0/255.0 alpha:1.0]];
[self.tableView setBackgroundView:nil];
[self.tableView setBackgroundView:[[UIView alloc] init]];
[self.view setBackgroundColor:[[UIColor alloc] initWithRed:167.0/255.0 green:169.0/255.0 blue:172.0/255.0 alpha:1.0]];
UIImageView *cellImage = (UIImageView *)[cell viewWithtag:88];
cellImage.image = [UIImage imageNamed:#"next#2x.png"];
}

Answer 4

Fixed using the following code:
UIImageView *cellImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"next#2x.png"]];
[cell setAccessoryView:cellImage];