仅当在 Visual Studio 2019 中以 C++ 模式编译静态库时，代码链接

问：

我创建了一个链表管理器的 WIN32 静态库，我一直将其用于 C/C++ 开发。

我在 Visual Studio 2019 上编译了这个库，强制它编译为 C 代码（VS2019 首选项中的选项）。但是，我确实使用了/TC

#ifdef __cplusplus
extern "C" {
#endif

以防万一我的静态库会被 C++ 程序使用。这是标题的链接。

但是，当我在 C++ 项目中使用此静态库时，我收到链接器错误

1>quickDAQ.obj : error LNK2019: unresolved external symbol "unsigned long __cdecl cListLength(struct _cLinkedList *)" (?cListLength@@YAKPAU_cLinkedList@@@Z) referenced in function "void __cdecl quickDAQstart(void)" (?quickDAQstart@@YAXXZ)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "int __cdecl cListEmpty(struct _cLinkedList *)" (?cListEmpty@@YAHPAU_cLinkedList@@@Z) referenced in function "void __cdecl setSampleClockTiming(enum _sampling_modes,double,char *,enum _trigger_modes,unsigned __int64,bool)" (?setSampleClockTiming@@YAXW4_sampling_modes@@NPADW4_trigger_modes@@_K_N@Z)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "struct _cListElem * __cdecl cListFirstElem(struct _cLinkedList *)" (?cListFirstElem@@YAPAU_cListElem@@PAU_cLinkedList@@@Z) referenced in function "void __cdecl enumerateNIDevices(void)" (?enumerateNIDevices@@YAXXZ)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "struct _cListElem * __cdecl cListNextElem(struct _cLinkedList *,struct _cListElem *)" (?cListNextElem@@YAPAU_cListElem@@PAU_cLinkedList@@PAU1@@Z) referenced in function "void __cdecl enumerateNIDevices(void)" (?enumerateNIDevices@@YAXXZ)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "void * __cdecl cListFirstData(struct _cLinkedList *)" (?cListFirstData@@YAPAXPAU_cLinkedList@@@Z) referenced in function "void __cdecl syncSampling(void)" (?syncSampling@@YAXXZ)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "int __cdecl cListInit(struct _cLinkedList *)" (?cListInit@@YAHPAU_cLinkedList@@@Z) referenced in function "void __cdecl enumerateNIDevices(void)" (?enumerateNIDevices@@YAXXZ)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "int __cdecl cListAppend(struct _cLinkedList *,void *)" (?cListAppend@@YAHPAU_cLinkedList@@PAX@Z) referenced in function "void __cdecl enumerateNIDevices(void)" (?enumerateNIDevices@@YAXXZ)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "int __cdecl cListPrepend(struct _cLinkedList *,void *)" (?cListPrepend@@YAHPAU_cLinkedList@@PAX@Z) referenced in function "void __cdecl pinMode(unsigned int,enum _IOmodes,unsigned int)" (?pinMode@@YAXIW4_IOmodes@@I@Z)
1>quickDAQ.obj : error LNK2019: unresolved external symbol "void __cdecl cListUnlinkElem(struct _cLinkedList *,struct _cListElem *)" (?cListUnlinkElem@@YAXPAU_cLinkedList@@PAU_cListElem@@@Z) referenced in function "void __cdecl enumerateNIDevices(void)" (?enumerateNIDevices@@YAXXZ)
1>C:\Users\tyros\codebase\testingLinkedList\Debug\testingLinkedList.exe : fatal error LNK1120: 9 unresolved externals
1>Done building project "testingLinkedList.vcxproj" -- FAILED.

显然，链接器无法链接到静态库。

但是，如果我使用设置为 C++ （） 的编译为标志编译静态库，则我在其中使用此库的项目编译时不会出现上述错误。/TP

为什么会这样？