iOS编译报错 "_OBJC_CLASS_$_Test", referenced from:objc-class-ref in ViewController.o

先贴一下错误：

Undefined symbols for architecture x86_64:
  "_OBJC_CLASS_$_Test", referenced from:
      objc-class-ref in ViewController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

1、新建工程引入Test这个类，首先targets不勾选

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然后在viewController里面创建这个Test对象

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此时编译就会报这个错误

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解决：

29AD4C9A-02FD-4685-9F6C-E4D125BE8758.png

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因为在编译过程中，compile sources不存在这个类，所以会报错，
此时再次编译一下OK