1:Undefined symbols for architecture arm64: "OBJC_CLASS$_类名", referenced from
报错: Undefined symbols for architecture arm64: “OBJC_CLASS$_类名”, referenced from : Objc-class-ref in 类名.o
错误原因为错失了红色箭头所指类名的文件
添加确是文件如下图所示
选中工程TARGETa工程名 - Build Phases - Compile Sources - 添加所缺失的类.m
如图所示: