UILabel 设置行间距 && 自动计算text 的frame

 NSMutableAttributedString * attributedString1 = [[NSMutableAttributedString alloc] initWithString:testString];
 NSMutableParagraphStyle * paragraphStyle1 = [[NSMutableParagraphStyle alloc] init];
 [paragraphStyle1 setLineSpacing:15];
 [attributedString1 addAttribute:NSParagraphStyleAttributeName value:paragraphStyle1 range:NSMakeRange(0, [testString length])];
 [cLabel setAttributedText:attributedString1];

 [cLabel sizeToFit];

转自：http://blog.csdn.net/daiyelang/article/details/45840591

- (CGRect)boundingRectWithSize:(CGSize)size options:(NSStringDrawingOptions)options attributes:(NSDictionary *)attributes context:(NSStringDrawingContext *)context 

不能返回正确的size

红色的使用

- (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode

能返回正确size

- (CGRect)boundingRectWithSize:(CGSize)size options:(NSStringDrawingOptions)options attributes:(NSDictionary *)attributes
是新的函数,你需要设置attributes相关属性.例如:

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
NSDictionary *attributes = @{NSFontAttributeName:label.font, NSParagraphStyleAttributeName:paragraphStyle.copy};
        
labelSize = [someText boundingRectWithSize:CGSizeMake(207, 999) options:NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil].size;