Question

I am a novice programmer. Already night trying to solve the problem, but did not work. I’m trying to dynamically change the size of a cell based on the content of information. Do by example, but my program startup dies. With the error:

 'Terminating app due to uncaught exception 'NSInvalidArgumentException', 
reason: '-[__NSDictionaryI sizeWithFont:constrainedToSize:lineBreakMode:]"     

What am I doing wrong? Here is my code:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] ;
    }

    NSDictionary *newsItem = [news objectAtIndex:indexPath.row];

    cell.textLabel.text = [newsItem objectForKey:@"title"];

    cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
    cell.textLabel.numberOfLines = 0;

    cell.detailTextLabel.text = [newsItem objectForKey:@"pubDate"];
    return cell;
}


- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *cellText = [news objectAtIndex:indexPath.row];
    UIFont *cellFont = [UIFont fontWithName:@"Helvetica-Bold" size:20.0f];
    CGSize constraintSize = CGSizeMake(320.0f, MAXFLOAT);

    CGSize labelSize = [cellText sizeWithFont:cellFont
                            constrainedToSize:constraintSize
                                lineBreakMode:UILineBreakModeWordWrap];

    return labelSize.height + 20.0f;
}

Answer 1

It appears that your news array has dictionaries in it, not strings. So in tableView:heightForRowAtIndexPath: your NSString* cellText is actually a NSDictionary*.

You just need to add an objectForKey: call after objectAtIndex: like so:

NSString *cellText = [[news objectAtIndex:indexPath.row] objectForKey:@"title"];