My UITableViewCell is reusing a previous cells UIImage - ios

Question

I have a UITable that reuses cells. Each cell has an image dependant on a condition. The correct images are always used however when cells are reused the old image is displayed behind the new one. I have tried to remove the uiimageview before adding a new subview however it has no effect.
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *simpTableIden = #"simpTableIden";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpTableIden];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpTableIden];
}
NSUInteger row = [indexPath row];
cell.textLabel.text = [[self.achievements objectForKey:[keys objectAtIndex:row]] objectForKey:#"name"];
CGRect picFrame = CGRectMake(cell.frame.size.width-cell.frame.size.height, 0, cell.frame.size.height, cell.frame.size.height);
UIImage *greyDot = [UIImage imageNamed:#"greyDot.png"];
UIImage *whiteDot = [UIImage imageNamed:#"whiteDot.png"];
UIImageView *achievImg = [[UIImageView alloc] init];
tableView.backgroundColor = [UIColor clearColor];
achievImg.frame=picFrame;
if ([[[self.achievements objectForKey:[keys objectAtIndex:row]] objectForKey:#"achieved"] boolValue]) {
achievImg.image = whiteDot;
}
else {
achievImg.image = greyDot;
}
[achievImg removeFromSuperview];
[cell.contentView addSubview:achievImg];
return cell;
}
Any help would be greatly appreciated?

Answer 1

The problem is each time cellForRowAtIndexPath: is called you create a new imageview.
I corrected your code as follows:
Here we create an imageView once for each new new cell and replace it's image every time cellForRowAtIndexPath: is called:
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *simpTableIden = #"simpTableIden";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpTableIden];
UIImageView *achievImg = nil;
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpTableIden];
//New Cell ... Create Image view
achievImg = [[UIImageView alloc] init];
achievImg.tag = 10;
[cell.contentView addSubview:achievImg];
}
else{
//Old cell...get previously createdd imageview
achievImg = (UIImageView*)[cell.contentView viewWithTag:10];
}
NSUInteger row = [indexPath row];
cell.textLabel.text = [[self.achievements objectForKey:[keys objectAtIndex:row]] objectForKey:#"name"];
CGRect picFrame = CGRectMake(cell.frame.size.width-cell.frame.size.height, 0, cell.frame.size.height, cell.frame.size.height);
UIImage *greyDot = [UIImage imageNamed:#"greyDot.png"];
UIImage *whiteDot = [UIImage imageNamed:#"whiteDot.png"];
tableView.backgroundColor = [UIColor clearColor];
achievImg.frame=picFrame;
if ([[[self.achievements objectForKey:[keys objectAtIndex:row]] objectForKey:#"achieved"] boolValue]) {
achievImg.image = whiteDot;
}
else {
achievImg.image = greyDot;
}
//You don't need this because it doesn't have a superview in the first place..it's new
//[achievImg removeFromSuperview];
return cell;
}

Answer 2

try like this,
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *simpTableIden = #"simpTableIden";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpTableIden];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpTableIden];
NSUInteger row = [indexPath row];
cell.textLabel.text = [[self.achievements objectForKey:[keys objectAtIndex:row]] objectForKey:#"name"];
CGRect picFrame = CGRectMake(cell.frame.size.width-cell.frame.size.height, 0, cell.frame.size.height, cell.frame.size.height);
UIImage *greyDot = [UIImage imageNamed:#"greyDot.png"];
UIImage *whiteDot = [UIImage imageNamed:#"whiteDot.png"];
UIImageView *achievImg = [[UIImageView alloc] init];
tableView.backgroundColor = [UIColor clearColor];
achievImg.frame=picFrame;
if ([[[self.achievements objectForKey:[keys objectAtIndex:row]] objectForKey:#"achieved"] boolValue]) {
achievImg.image = whiteDot;
}
else {
achievImg.image = greyDot;
}
[achievImg removeFromSuperview];
[cell.contentView addSubview:achievImg];
}
return cell;
}

Answer 3

You are always adding the imageView to the contentView of the cell. If the cell is reused that will lead to multiple imageViews in cell.
You can give a tag to the imageView. Always check if there is a view will same tag in the contentView of cell. If not add the imageView.
UIImageView *achievImg = (UIImageView *)[cell.contentView viewWithTag:55];
if(!achievImg){
achievImg = [[UIImageView alloc] init];
achievImg.tag = 55;
[cell.contentView addSubView:achievImg];
}