1.图片的拉伸效果
http://www.cnblogs.com/heyonggang/archive/2013/12/19/3482733.html
UIImage *together =[UIImage imageNamed:@"togetherGone"];
together = [together resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 15)];
self.togetherImageView.image = together;