Adjust UILabel to change it's frame according to it's content

UILabel+dynamicSizeMe.h

@interface UILabel (dynamicSizeMe)

-(float)resizeToFit;
-(float)expectedHeight;

@end

UILabel+dynamicSizeMe.m

#import "UILabel+dynamicSizeMe.h"

@implementation UILabel (dynamicSizeMe)

-(float)resizeToFit{
    float height = [self expectedHeight];
    CGRect newFrame = [self frame];
    newFrame.size.height = height;
    [self setFrame:newFrame];
    return newFrame.origin.y + newFrame.size.height;
}

-(float)expectedHeight{
    [self setNumberOfLines:0];
    [self setLineBreakMode:UILineBreakModeWordWrap];

    CGSize maximumLabelSize = CGSizeMake(self.frame.size.width,9999);
    
    CGSize expectedLabelSize = [[self text] sizeWithFont:[self font] 
                                            constrainedToSize:maximumLabelSize
                                            lineBreakMode:[self lineBreakMode]]; 
    return expectedLabelSize.height;
}

@end

Shorter version:

[label sizeToFit];
or
[label sizeThatFits:maxSize];

Daniel, It's also a good idea to use prefixes on method names when you are adding a category to an existing system class. If Apple ever adds resizeToFit this is going to cause breakage.

It won't cause breakage Abizern, it will merely override the already existing method. That is the behavior of categories.

I've changed -(float)expectedHeight method to work in iOS7 and Xcode 5 without any warnings. Hope it will help someone:

-(float)expectedHeight {

[self setNumberOfLines:0];
[self setLineBreakMode:NSLineBreakByCharWrapping];

UIFont *font = [UIFont systemFontOfSize:14.0]; //Warning! It's an example, set the font, you need

NSDictionary *attributesDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                      font, NSFontAttributeName,
                                      nil];

CGSize maximumLabelSize = CGSizeMake(self.frame.size.width,9999);

CGRect expectedLabelRect = [[self text] boundingRectWithSize:maximumLabelSize
                                                     options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading)
                                                  attributes:attributesDictionary
                                                     context:nil];
CGSize *expectedLabelSize = &expectedLabelRect.size;

return expectedLabelSize->height;

}

Thanks @WingedDoom

Your answer made me create this:

    ...
    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320, 80)];
    [titleLabel setText:response[@"title"]];
    [titleLabel setFont:[UIFont fontWithName:@"HelveticaNeue-Bold" size:22]];
    [ATStringHelper setExpectedHeightForLabel:titleLabel maxHeight:80];
    [self.view addSubview: titleLabel];
}

- (void)setExpectedHeightForLabel:(UILabel *)label maxHeight:(CGFloat)maxHeight
{
    [label setNumberOfLines:0];
    [label setLineBreakMode:NSLineBreakByWordWrapping];
    CGSize currentLabelSize = CGSizeMake(label.frame.origin.x, label.frame.origin.y);

    NSDictionary *attributesDictionary = @{NSFontAttributeName:label.font};
    CGSize maximumLabelSize = CGSizeMake(label.frame.size.width, maxHeight);
    CGRect expectedLabelRect = [label.text boundingRectWithSize:maximumLabelSize options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading) attributes:attributesDictionary context:nil];
    CGSize expectedLabelSize = expectedLabelRect.size;
    [label setFrame:CGRectMake(currentLabelSize.width, currentLabelSize.height, expectedLabelSize.width, expectedLabelSize.height)];
}

i only wanted to know the size of the label reduces according to the data but it is alwaz in single line....max 45 charc