此处的问题是，包含类别的库无法在早期版本的Xcode中正确加载.从4.6开始，它们应该正在加载，并且您应该只能使用链接器标志"-ObjC"，该标志告诉链接器检查此类库.

The problem here is that libraries containing categories did not properly load in earlier versions of Xcode. As of 4.6 they should be loading, and you should be able to just use the linker flag "-ObjC", which tells the linker to examine the libraries for such things.

如果由于某种原因-ObjC标志不起作用，则强制加载的语法为"

If for some reason the -ObjC flag does not work, the syntax for the force load is"

-force_load $(BUILT_PRODUCTS_DIR)/libxyz.a