Undefined symbols for architecture x86_64:的一种解决办法

Undefined symbols for architecture x86_64:

  "_iconv_open", referenced from:

      _main in main.o

  "_iconv", referenced from:

      _main in main.o

  "_iconv_close", referenced from:

      _main in main.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

后来发现xcode就算使用系统自带的头文件也需要导入lib（sqlite和iconv，Mac都自带），也就是说，单单包含头文件是不够的，还需要加入lib或Framework，具体方法如下：

加上以后，一切正常。