keil编译时出现*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL

解决:包含该函数或变量的文件未添加到工程
*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL

解决:包含该函数或变量的文件未添加到工程