问题
I have two frameworks in my Xcode project that both define a class with the same name (B.framework and C.framework both have a class named MyClass), resulting in a couple warnings like so:
Duplicate symbol _OBJC_METACLASS_$_MyClass originally in B.framework/B(MyClass.o) now lazily loaded from C.framework/C(MyClass.o)
Duplicate symbol _OBJC_CLASS_$_MyClass originally in B.framework/B(MyClass.o) now lazily loaded from C.framework/C(MyClass.o)
Then at run time only one of the implementations is loaded, and trying to use the other one will result in a "unrecognized selector sent to instance" because they are totally different classes (even though they have the same name).
I use one of the MyClass implementations directly in my code, but the other framework only uses its MyClass internally and I have no idea why its even exported (its not even mentioned in the frameworks header files, i used nm to view the symbols).
How can I make both frameworks work?
回答1:
There's no such thing as "exported" classes in Obj-C. Or rather, there's no such thing as "non-exported" classes. This problem is precisely why the use of 2- or 3-letter prefixes on classes is strongly recommended for all Obj-C code. Your only solution (besides not using these frameworks) is to edit one (or both) of the frameworks to change the class name, or if you don't have access to the source, then you need to contact the vendor and ask them to make that change.
来源：https://stackoverflow.com/questions/8827348/two-frameworks-with-the-same-symbol