c++ - 当用户定义的 dll 引用另一个用户定义的 dll 时出现链接器错误

Question

我试图使用协议(protocol)层设计模式来实现协议(protocol)栈: http://www.eventhelix.com/realtimemantra/patterncatalog/protocol_layer.htm

在我们的项目中，我将所有层都作为单独的 dll。我拥有的图层是:

1. 应用层dll

2. LLC层dll

3. MAC 层 dll

4. 物理层dll

我在同一个解决方案中有另一个项目实现了设计模式和具有协议(protocol)层的一般功能的实现。我所有的层都继承自协议(protocol)层基类。之间的依赖项目如下:协议(protocol)层设计模式 dll:无依赖物理层dll:协议(protocol)设计模式dllMAC层dll:协议(protocol)设计模式dll和物理层dllLLC层dll:协议(protocol)设计模式dll和MAC层dll应用层dll:协议(protocol)设计模式dll和LLC层dll

基于设计模式，我们的每一层都有指向其上下层的指针。我们设计的流程是这样的:在应用层构造函数中，我们创建了一个对象 LLC 层然后 LLC 层创建 Mac 层，MAC 层又创建物理层。它们都是相连的使用指针。

我的协议(protocol)设计模式项目 dll 和物理层 dll 构建正确。但是其他 dll 构建正在提供链接器错误。对底层的构造函数说 Unresolved external 问题。这些是我遇到的错误。

==================================

1. 1>phLayer.obj : error LNK2019: unresolved external symbol "public:
   virtual __thiscall CProtocolLayer::~CProtocolLayer(void)"
   (??1CProtocolLayer@@UAE@XZ) referenced in function
   __unwindfunclet$??0CPhysicalLayer@@QAE@PAVCProtocolLayer@@@Z$0 1>phLayer.obj : error LNK2019: unresolved external symbol "public:
   __thiscall CReceiveProtocolHandler::CReceiveProtocolHandler(class CProtocolLayer *)"
   (??0CReceiveProtocolHandler@@QAE@PAVCProtocolLayer@@@Z) referenced in function "public: __thiscall CPhysicalLayer::CPhysicalLayer(class CProtocolLayer *)" (??0CPhysicalLayer@@QAE@PAVCProtocolLayer@@@Z) 1>phLayer.obj : error LNK2019: unresolved external symbol "public: __thiscall CTransmitProtocolHandler::CTransmitProtocolHandler(class CProtocolLayer *)"
   (??0CTransmitProtocolHandler@@QAE@PAVCProtocolLayer@@@Z) referenced in function "public: __thiscall CPhysicalLayer::CPhysicalLayer(class CProtocolLayer *)" (??0CPhysicalLayer@@QAE@PAVCProtocolLayer@@@Z)
   1>phLayer.obj : error LNK2019: unresolved external symbol "public:
   __thiscall CProtocolLayer::CProtocolLayer(class CProtocolLayer *,class CProtocolLayer *)" (??0CProtocolLayer@@QAE@PAV0@0@Z) referenced in function "public: __thiscall
   CPhysicalLayer::CPhysicalLayer(class CProtocolLayer *)"
   (??0CPhysicalLayer@@QAE@PAVCProtocolLayer@@@Z) 1>phLayer.obj : error LNK2019: unresolved external symbol "public: int __thiscall
   CProtocolPacket::getBodyLength(void)"
   (?getBodyLength@CProtocolPacket@@QAEHXZ) referenced in function
   "public: virtual void __thiscall CPhysicalLayer::Data_req(class
   CProtocolPacket *)"
   (?Data_req@CPhysicalLayer@@UAEXPAVCProtocolPacket@@@Z) 1>phLayer.obj : error LNK2019: unresolved external symbol "public: void __thiscall CReceiveProtocolHandler::Handle_Receive(class CProtocolPacket *)"
   (?Handle_Receive@CReceiveProtocolHandler@@QAEXPAVCProtocolPacket@@@Z) referenced in function "private: void __thiscall
   CPhysicalLayer::dataRead(void)" (?dataRead@CPhysicalLayer@@AAEXXZ)
   1>phLayer.obj : error LNK2019: unresolved external symbol "public:
   void __thiscall CProtocolPacket::AddTrailer(int,char *)"
   (?AddTrailer@CProtocolPacket@@QAEXHPAD@Z) referenced in function
   "private: class CProtocolPacket __thiscall
   CPhysicalLayer::convertToProtocolPacket(class
   std::basic_string,class
   std::allocator >)"
   (?convertToProtocolPacket@CPhysicalLayer@@AAE?AVCProtocolPacket@@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) 1>phLayer.obj : error LNK2019: unresolved external symbol "public:
   void __thiscall CProtocolPacket::AddHeader(int,char *)"
   (?AddHeader@CProtocolPacket@@QAEXHPAD@Z) referenced in function
   "private: class CProtocolPacket __thiscall
   CPhysicalLayer::convertToProtocolPacket(class
   std::basic_string,class
   std::allocator >)"
   (?convertToProtocolPacket@CPhysicalLayer@@AAE?AVCProtocolPacket@@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)

Answer 1

你是如何构建 exe 的？我看到了，您只面临链接器问题。您必须以错误的顺序链接，或者一定有什么地方出错了。尝试以正确的顺序链接它们。这应该可以解决问题。如果没有，请提供更多信息。