子类化 NullFederateAmbassador 时出现链接错误答案

【问题标题】：Link error when subclassing NullFederateAmbassador子类化 NullFederateAmbassador 时出现链接错误
【发布时间】：2021-09-02 16:29:50
【问题描述】：

我正在尝试用 C++ 编写自己的 RTI 实现。

我导入了 IEEE 1516 HLA 进化 API，并创建了 NullFederateAmbassador 的子类。

我收到了 60 多个未解决的外部符号错误，附在下面。

我写过的唯一 C++ 是这样的：

#include "pch.h"
#include "RTI/RTI1516.h"
#include "RTI/NullFederateAmbassador.h"

using namespace rti1516e;

class NullFederateAmbassadorChild : public NullFederateAmbassador {

};

void Connect() {
    NullFederateAmbassadorChild c;
}

代码在 IntelliSense 中连接良好。我的 pch.h 里面什么都没有。 RTI 文件与来自 IEEE 的原始 RTI 文件完全一致。

1>CBRTILibrary.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl rti1516e::NullFederateAmbassador::NullFederateAmbassador(void)" (__imp_??0NullFederateAmbassador@rti1516e@@QEAA@XZ) referenced in function "public: __cdecl NullFederateAmbassadorChild::NullFederateAmbassadorChild(void)" (??0NullFederateAmbassadorChild@@QEAA@XZ)
1>CBRTILibrary.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __cdecl rti1516e::NullFederateAmbassador::~NullFederateAmbassador(void)" (__imp_??1NullFederateAmbassador@rti1516e@@UEAA@XZ) referenced in function "public: virtual __cdecl NullFederateAmbassadorChild::~NullFederateAmbassadorChild(void)" (??1NullFederateAmbassadorChild@@UEAA@XZ)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::announceSynchronizationPoint(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> > const &,class rti1516e::VariableLengthData const &)" (?announceSynchronizationPoint@NullFederateAmbassador@rti1516e@@UEAAXAEBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@AEBVVariableLengthData@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::attributeIsNotOwned(class rti1516e::ObjectInstanceHandle,class rti1516e::AttributeHandle)" (?attributeIsNotOwned@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@VAttributeHandle@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::attributeIsOwnedByRTI(class rti1516e::ObjectInstanceHandle,class rti1516e::AttributeHandle)" (?attributeIsOwnedByRTI@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@VAttributeHandle@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::attributeOwnershipAcquisitionNotification(class rti1516e::ObjectInstanceHandle,class std::set<class rti1516e::AttributeHandle,struct std::less<class rti1516e::AttributeHandle>,class std::allocator<class rti1516e::AttributeHandle> > const &,class rti1516e::VariableLengthData const &)" (?attributeOwnershipAcquisitionNotification@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@AEBV?$set@VAttributeHandle@rti1516e@@U?$less@VAttributeHandle@rti1516e@@@std@@V?$allocator@VAttributeHandle@rti1516e@@@4@@std@@AEBVVariableLengthData@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::attributeOwnershipUnavailable(class rti1516e::ObjectInstanceHandle,class std::set<class rti1516e::AttributeHandle,struct std::less<class rti1516e::AttributeHandle>,class std::allocator<class rti1516e::AttributeHandle> > const &)" (?attributeOwnershipUnavailable@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@AEBV?$set@VAttributeHandle@rti1516e@@U?$less@VAttributeHandle@rti1516e@@@std@@V?$allocator@VAttributeHandle@rti1516e@@@4@@std@@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::attributesInScope(class rti1516e::ObjectInstanceHandle,class std::set<class rti1516e::AttributeHandle,struct std::less<class rti1516e::AttributeHandle>,class std::allocator<class rti1516e::AttributeHandle> > const &)" (?attributesInScope@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@AEBV?$set@VAttributeHandle@rti1516e@@U?$less@VAttributeHandle@rti1516e@@@std@@V?$allocator@VAttributeHandle@rti1516e@@@4@@std@@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::attributesOutOfScope(class rti1516e::ObjectInstanceHandle,class std::set<class rti1516e::AttributeHandle,struct std::less<class rti1516e::AttributeHandle>,class std::allocator<class rti1516e::AttributeHandle> > const &)" (?attributesOutOfScope@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@AEBV?$set@VAttributeHandle@rti1516e@@U?$less@VAttributeHandle@rti1516e@@@std@@V?$allocator@VAttributeHandle@rti1516e@@@4@@std@@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::confirmAttributeOwnershipAcquisitionCancellation(class rti1516e::ObjectInstanceHandle,class std::set<class rti1516e::AttributeHandle,struct std::less<class rti1516e::AttributeHandle>,class std::allocator<class rti1516e::AttributeHandle> > const &)" (?confirmAttributeOwnershipAcquisitionCancellation@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@AEBV?$set@VAttributeHandle@rti1516e@@U?$less@VAttributeHandle@rti1516e@@@std@@V?$allocator@VAttributeHandle@rti1516e@@@4@@std@@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::confirmAttributeTransportationTypeChange(class rti1516e::ObjectInstanceHandle,class std::set<class rti1516e::AttributeHandle,struct std::less<class rti1516e::AttributeHandle>,class std::allocator<class rti1516e::AttributeHandle> >,enum rti1516e::TransportationType)" (?confirmAttributeTransportationTypeChange@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@V?$set@VAttributeHandle@rti1516e@@U?$less@VAttributeHandle@rti1516e@@@std@@V?$allocator@VAttributeHandle@rti1516e@@@4@@std@@W4TransportationType@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::confirmInteractionTransportationTypeChange(class rti1516e::InteractionClassHandle,enum rti1516e::TransportationType)" (?confirmInteractionTransportationTypeChange@NullFederateAmbassador@rti1516e@@UEAAXVInteractionClassHandle@2@W4TransportationType@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::connectionLost(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> > const &)" (?connectionLost@NullFederateAmbassador@rti1516e@@UEAAXAEBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::discoverObjectInstance(class rti1516e::ObjectInstanceHandle,class rti1516e::ObjectClassHandle,class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> > const &)" (?discoverObjectInstance@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@VObjectClassHandle@2@AEBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::discoverObjectInstance(class rti1516e::ObjectInstanceHandle,class rti1516e::ObjectClassHandle,class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> > const &,class rti1516e::FederateHandle)" (?discoverObjectInstance@NullFederateAmbassador@rti1516e@@UEAAXVObjectInstanceHandle@2@VObjectClassHandle@2@AEBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@VFederateHandle@2@@Z)
1>CBRTILibrary.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl rti1516e::NullFederateAmbassador::federationNotRestored(enum rti1516e::RestoreFailureReason)" (?federationNotRestored@NullFederateAmbassador@rti1516e@@UEAAXW4RestoreFailureReason@2@@Z)
1>mainRti.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl  . . . . . . . . etc

1>C:\Dev\x64\Debug\myRTI.dll : fatal error LNK1120: 62 unresolved externals

【问题讨论】：

这能回答你的问题吗？ What is an undefined reference/unresolved external symbol error and how do I fix it?
@Frank 这是一个公共 API，应该可以解决问题。使用 API 的教程说只继承“NullFederateAmbassador”并覆盖你想要的任何东西。
这个问题很可能是您实际上没有将 API 的库添加到您的项目中，但是还有一些其他的事情可能会导致该错误。我链接的 Q/A，尤其是接受的答案，应该为您提供所需的所有详细信息。
@Frank 我的 IntelliSense 工作正常，并且我为 API 设置了包含目录（这只是 .h 文件的集合，没有 .lib 或 .dll 文件）。
哦，我明白了。这些标头是库的规范。您仍然需要提供一个实现来配合它。在谷歌上快速搜索“rti1516e 开源实现”将为您提供一些公开可用的替代方案。

标签： c++ unity3d linker-errors distributed-system high-level-architecture

【解决方案1】：

IEEE HLA 1516-2010（AKA HLA 1516 Evolved）只是 API 的定义。创建具有实际功能的 RTI 取决于开发人员。那里有几个商业 RTIs 以及少数 FOSS。我知道 Pitch 和 MaK 销售实施 1516-2010 的产品。最受欢迎的开源实现是 Portico (https://porticoproject.org/)。

一旦您拥有 RTI（或自己编写，如果您愿意），您需要编译联邦并将其链接到 RTI 提供的库。

【讨论】：