//计算文本的高度 commentLabel定义的成员变量
int version=[[UIDevice currentDevice].systemVersion intValue];
NSLog(@"当前系统的版本:%d",version);
//评论Label的适配
NSString *commendStr=[NSString stringWithFormat:@"%d条评论",[model.comments intValue]];
if (version>7) {
//根据内容的多少调整label的大小(新的API，用来替换下面的)
CGSize size=[commendStr boundingRectWithSize:CGSizeMake(MAXFLOAT, self.commentLabel.frame.size.height) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:self.commentLabel.font} context:nil].size;
self.commentLabel.text=commendStr;
self.commentLabel.frame=CGRectMake(self.commentLabel.x, self.commentLabel.y,size.width, self.commentLabel.height);
NSLog(@"版本大于7.0");
}else{
//根据内容的多少调整label的大小(老的API)
CGSize size=[commendStr sizeWithFont:_commentLabel.font constrainedToSize:CGSizeMake(MAXFLOAT, _commentLabel.frame.size.height) lineBreakMode:NSLineBreakByWordWrapping];
_commentLabel.text=commendStr;
_commentLabel.frame=CGRectMake(_commentLabel.x, _commentLabel.y, size.width, _commentLabel.height);
NSLog(@"版本较低");
}