向UISwitch添加行为(Add behaviour to UISwitch)

 我在我的IOS应用程序的许多地方使用UISwitch 。 其中一些是库存UISwitch ，其中一些是subclassed 。 事情是在iOS 6 VS iOS 7的大小变化。 所以我写了这个方法： 
 
-(void)layoutSubviews{
    if ([[[UIDevice currentDevice]systemVersion]intValue]<7) {
        self.frame = CGRectMake(self.frame.origin.x-28, self.frame.origin.y, self.frame.size.width, self.frame.size.height);
    }
}
 
 我可以更改每个子类并添加此方法，但我不认为这是正确的方法。 如何设置此类以影响基础UISwitch类？ 

I am using UISwitch in many places of my IOS app. Some of them are stock UISwitch and some of them are subclassed. The thing is in iOS 6 VS iOS 7 the size changes. So I wrote this method :
 
-(void)layoutSubviews{
    if ([[[UIDevice currentDevice]systemVersion]intValue]<7) {
        self.frame = CGRectMake(self.frame.origin.x-28, self.frame.origin.y, self.frame.size.width, self.frame.size.height);
    }
}
 
I can change every subclass and add this method but I don't think this is the wright approach. How can I set this class to effect the base UISwitch class?

原文：https://stackoverflow.com/questions/20782200