iOS Undefined symbols for architecture arm64解决办法

Undefined symbols for architecture arm64:
  "_OBJC_CLASS_$_YYCache", referenced from:
      objc-class-ref in LFNetworking.o
  "_OBJC_CLASS_$_AFHTTPRequestSerializer", referenced from:
      objc-class-ref in LFNetworking.o
  "_OBJC_CLASS_$_AFJSONResponseSerializer", referenced from:
      objc-class-ref in LFNetworking.o
  "_OBJC_CLASS_$_AFHTTPSessionManager", referenced from:
      objc-class-ref in LFNetworking.o
ld: symbol(s) not found for architecture arm64

出现这种错误有多种可能：

1.Build Setting->Architectures查看是否包含arm64指令集

2.如果用CocoaPods导入的库，Build Setting->Linking->Other Linker Flags，添加$(inherited)

3.该类只有@interface，没有@implementation

暂时列出这几种，以后遇到了再补充