管理对iOS6和iOS7的支持的最佳方法是什么？

Question

I always have an app requirement to support both iOS6 and iOS7 . But because of iOS6 support, I can't use some feature of iOS7 .

For example, I have to do UIView bounce animation, in iOS6 I have to do it with CAKeyframeAnimation or UIView animation, but iOS7 has UIKit dynamics which provide me UIDynamicAnimator class and I can do with it.

So should I always use older methods like CAKeyframeAnimation or UIView animation because it supports both iOS6 and iOS7 or write both by checking iOS version?

Answer 1

Ruthlessly strip things from the iOS 6 version that require ios7 features to work, particularly if they are cosmetic things like bouncing animations.

When challenged about this, tell your client they can spend 80% of their dev budget supporting an ever-shrinking pool of unconcerned users, or they can get real. API compatibility is only one headache between 6 and 7. The layout issues are far harder. Any new app being written today needs a really, really good reason to support 6, particularly with 8 just round the corner.

Answer 2

I believe the best way is to check iOS version and implement both variants of code.

Yes, maybe, it's quite a lot of work but in majority of cases newest features provided in new iOS releases are more flexible and simple to understand/integrate. In most cases they are also more plain in support. They are supported by Apple with more care and there is a small possibility of their deprecation.

You can use Foundation runtime variable NSFoundationVersionNumber and NSFoundationVersionNumber_iOS_6_1 macros to divide your code:

if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_6_1) {
    // write iOS 7+ code here 
} 
else {
    // write iOS 6.1- code here 
}

Note, sometimes some recent released API can be quite raw. In such cases you should take a decision individually whether you really need the migration immediately.

Answer 3

You can use class API to check for availability of classes.

if ([UIPrintInteractionController class]) {
   // Create an instance of the class and use it.
}
else {
   // The print interaction controller is not available.
}

For more information see link below Advanced App Tricks