Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 clang: error: linker command faile
解决办法:Swift : 在Build Phases 中的compile sources中添加APPDelegate.swift文件
Objective-C :在Build Phases 中的compile sources中添加main.m文件