Question

I read that because of the dequeueReusableCellWithIdentifier method grabbing an oldCell if there is one available to use rather than creating a new one, if I have special views to show, like images or checkmarks, that I want to explicitly say, show = YES or show = NO for the cell so the cell doesn’t end up using a cell with an old graphic on it and I end up getting an image I don’t want on my view.

So in this case, I have a UITableView inside a popover. It is a grouped table. The groups have 2-4 cells depending on the data. I am using the UITableViewCellStyleValue2 like the contacts application. I want to add an image to the right side of the cell on the first cell in the group only depending on the data. It works, however, once I scroll the table, it picks up a dequeued cell and then I’ll get one of the images on the right hand side for a cell that is not even the first cell. I did not create a UITableViewCell subclass, and am unsure if I need to add this point so I have control over the imageView I’m adding to the cell.

So here’s the important part of the cellForRowAtIndexPath method:

if (row == 0) {
    UIImage *dot;
    if (aTarget.importance == TargetImportanceHigh) {
        dot = [UIImage imageNamed:@"dot_red.png"];
    }
    else if (aTarget.importance == TargetImportanceLow) {
        dot = [UIImage imageNamed:@"dot_yellow.png"];
    }
    else {
        dot = [UIImage imageNamed:@"dot_black.png"];
    }
    UIImageView *imgView = [[UIImageView alloc] initWithImage:dot];
    imgView.frame = CGRectMake(cell.frame.size.width - 50, cell.frame.size.height / 2 - 7.5, 15, 15);
    [cell.contentView addSubview:imgView];
    [imgView release];

    cell.textLabel.text = @"Location
    cell.detailTextLabel.text = [NSString stringWithFormat:@"%i", aTarget.location];
}
else if (row == 1) {
    cell.textLabel.text = @"Coordinate";
    cell.detailTextLabel.text = [NSString stringWithFormat:@"%@", aTarget.coordinate];
}
return cell;

Answer 1

You should do this via a UITableViewCell subclass, and then you can clear your second UIImageView in prepareForReuse

e.g.

@implementation MyTableViewCellSubclass


// other methods
// ...

- (void)prepareForReuse {
    [super prepareForReuse];

    self.otherImageView.image = nil;
}

@end