UITableViewCell from cellForRowAtIndexPath has subview not updating - iphone

Question

In my cellForRowAtIndexPath, I'm doing some custom formatting on a subview for when that cell is selected. The complete function is:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UIView *left;
UIImageView *leftImage;
UILabel *label;
ArticleButton *btn;
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:#"UITableViewCell"];
if (!cell)
{
cell = [[[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:#"UITableViewCell"] autorelease];
left = [[[UIView alloc] initWithFrame:CGRectMake(0, 2, 155, 139)] autorelease];
leftImage = [[[UIImageView alloc] initWithFrame:CGRectMake(7,9,141,77)] autorelease];
label = [[[UILabel alloc] initWithFrame:CGRectMake(6,87,141,48)] autorelease];
btn = [[[ArticleButton alloc] initWithFrame:CGRectMake(0,2,155,139)] autorelease];
left.tag = 0;
leftImage.tag = 1;
label.tag = 2;
btn.tag = 3;
[btn addTarget:self action:#selector(selectArticle:) forControlEvents:UIControlEventTouchUpInside];
[cell.contentView addSubview:left];
[cell.contentView addSubview:leftImage];
[cell.contentView addSubview:label];
[cell.contentView addSubview:btn];
}
else
{
left = (UIView*)[cell viewWithTag:0];
leftImage = (UIImageView*)[cell viewWithTag:1];
label = (UILabel*)[cell viewWithTag:2];
btn = (ArticleButton*)[cell viewWithTag:3];
}
...load *entry
NSURL *url = [NSURL URLWithString:[entry imageUrl]];
FeedEntry* selectedEntry = [detailViewController detailItem];
NSString* selectedTitle = selectedEntry.title;
if ([selectedTitle isEqualToString:entry.title])
{
[left setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"cellbackground_sel.png"]]]; <-- PROBLEM IS THIS IMAGE NEVER CHANGES
NSLog(#"selected row %#", selectedTitle);
}
else{
[left setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"cellbackground2.png"]]];
}
[left setNeedsDisplay];
[leftImage setImageWithURL:url placeholderImage:[UIImage imageNamed:#"placeholder.gif"]];
[leftImage setContentMode:UIViewContentModeScaleAspectFill];
leftImage.clipsToBounds = YES;
[label setBackgroundColor:[UIColor clearColor]];
label.textColor = [UIColor whiteColor];
label.text = [entry.title stringByAppendingString:#"\n\n"];
label.numberOfLines = 3;
label.lineBreakMode = UILineBreakModeClip;
label.font = [UIFont fontWithName:#"Arial-BoldMT" size:12];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
}
The problem I'm having is with this section:
if ([selectedTitle isEqualToString:entry.title])
{
[left setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"cellbackground_sel.png"]]];
NSLog(#"selected row %#", selectedTitle);
}
else{
[left setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"cellbackground2.png"]]];
}
Everything else works, but although I'm logging that it gets called, but the background of my subview to indicate that the row in question is a selected row, never changes. I've tried calling setNeedsDisplay, I've tried scrolling up and down trying to get the cells to dequeue and get recreated, it just never users the other image, even though it logs that the row being drawn was a selected row.
(Once I get this working, I need to implement the "right" section to have two "cells" in the one row and only one will be selected. That's why I'm doing it this way with subviews in the cell).
What am I doing wrong?

Answer 1

I think it is a problem to set the tag to zero. The documentation says:
viewWithTag:
Return Value
The view in the receiver’s hierarchy whose tag property matches the value in the tag parameter.
Discussion
This method searches the current view and all of its subviews for the specified view.
If think that most views tag is zero, even that of the current cell's view. I think that you dont get the correct view out of it. Try not to use 0 as a tag to work with.

Answer 2

Whenever a particular UITableViewCell is selected, this particular delegate is called -
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
Try to see if your button taps are being first responded by this delegate rather than going to selectArticle: selector you have defined...

Answer 3

Instead of setting this in tableview:cellForRowAtIndexPath:, try doing it in the tableview:willSelectRowAtIndexPath:
See the protocol reference for further details.