UIButton 图片文字上下对齐

UIImage *buttonImg = [button imageForState:UIControlStateNormal];
CGFloat titleWidth = [button.titleLabel.text sizeWithAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIFont boldSystemFontOfSize:18],NSFontAttributeName, nil]].width;
[button setTitleEdgeInsets:UIEdgeInsetsMake(buttonImg.size.height, -buttonImg.size.width, 0, 0)];
[button setImageEdgeInsets:UIEdgeInsetsMake(-15, 0, 0, -titleWidth)];