Problems with sizes and lines in UILabel - ios

Question

I have a little question. I developed an application that automatically fills a data set obtained from a SQLite database. These data are drawn from dynamic way, and between the data I have a frame where I insert labels dynamically. I never know the exact number of labels inside these frame because I take data from different tables of my Database. The problem I have with the labels which texts within them do not fill within the width of the label. I tried to use label.linebreakmode but still makes the break. I post the code:
There I have many objects taken from previous code, like widthFormato and widthImageFormato
if([tipoVino length]!=0){
UILabel *lblFormato = [[UILabel alloc] init];
labelX = ((widthFormato-widthImageFormatos) / 2)+10;
CGRect labelFrame = lblFormato.frame;
labelFrame.size.width = widthImageFormatos;
labelFrame.origin.x = labelX;
labelFrame.origin.y = labelY+25;
lblFormato.frame = labelFrame;
lblFormato.numberOfLines = 0;
lblFormato.lineBreakMode = NSLineBreakByWordWrapping;
[lblFormato setText:[NSString stringWithFormat:#"- %#",tipoVino]];
lblFormato.textColor = [UIColor whiteColor];
labelY = lblFormato.frame.origin.y;
[formatosImageView addSubview:lblFormato];
}

Answer 1

I think that you want to create labels with flexible height (not all have the same size), and must fix the width of formatosImageView.
EDITED FOR iOS7
I was using sizeWithFont that is deprecated in iOS7, I changed it for boundingRectWithSize
Try this:
UILabel *lblFormato = [[UILabel alloc] init];
lblFormato.numberOfLines = 0;
lblFormato.lineBreakMode = NSLineBreakByWordWrapping;
[lblFormato sizeToFit];
NSString *string = [NSString stringWithFormat:#"- %#", tipoVino];
[lblFormato setText: string];
//Calculate the size of the container of the lblFormato
CGSize size = [string boundingRectWithSize:CGSizeMake(widthImageFormatos, 2000) options:NSStringDrawingUsesLineFragmentOrigin attributes:#{NSFontAttributeName: [UIFont fontWithName:#"customFont" size:fontSize]} context:nil];
lblFormato.frame = CGRectMake(labelX, labelY + 25, size.width, size.height);
and you must update the labelY with:
labelY = lblFormato.frame.size.height;
Maybe it helps you.

Answer 2

With regards #spinillos answer, for iOS 7:
NSDictionary *attributes = #{ NSFontAttributeName : [UIFont systemFontOfSize:<#fontSize#>] };
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc]
initWithString: <#string#>,
attributes:attributes];
CGRect frame = [attributedString boundingRectWithSize:CGSizeMake(<#width#>, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin context:nil];