1.sizeWithFont.(7.0废除) - > sizeWithAttributes
CGSize size = CGSizeZero;
size = [title sizeWithFont:[UIFont systemFontOfSize:15]]; -->
size = [title sizeWithAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15]}];
2.
原文：http://www.cnblogs.com/Ganggang888/p/7262284.html