iOS 7状态栏半透明，具有向后兼容性

I built my app to have a translucent navbar in iOS 6. I'd like to utilize the translucent status bar in iOS 7 and keep the app as is in iOS 6, but my content is always underneath the status bar in iOS 7, with 20px missing on the bottom. I figure that I can make the very tedious code changes that check whether the device has iOS 7 and then adjust my content accordingly, but I fear that this is going to be a lot of work.I built my app to have a translucent navbar in