// 计算文字的宽高
NSDictionary *attributesDic = @{NSFontAttributeName: self.labelView.font};
CGRect textRect = [text boundingRectWithSize:CGSizeMake(200, 100) options:NSStringDrawingUsesLineFragmentOriginattributes:attributesDic context:nil];
原文：http://www.cnblogs.com/yangmx/p/3800404.html