Undefined symbols for architecture i386:
"_OBJC_CLASS_$_Possession", referenced from:
objc-class-ref in PossessionStroe.o
(maybe you meant: _OBJC_CLASS_$_PossessionStroe)
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
在网上搜了下，是相关的文件没有关联到对应的target，点击报错的类的实现文件，将其关联到target，右侧边栏的target membership