Question

I have an application designed for iPhone OS 2.0 and I am adding some new 3.x functionality to it. My idea is to maintain compatibility with older versions.

I have managed so far, to test for deprecated functions using “if respondToSelector…”. This is just fine for calls inside a method but how to deal with method name changes? For example, the OS 2.x method

-imagePickerController:didFinishPickingImage:editingInfo:

changed in OS 3.x to

-imagePickerController:didFinishPickingMediaWithInfo:

How can I test for the OS version and direct the application to the proper method in this case?

thanks for any help.

Answer 1

You can use NSObject’s -respondsToSelector method to dynamically determine if the method exists, then call it. You might also want to use -performSelector:withObject: to call the methods, so you don’t get compiler warnings.