未解决的虚函数链接错误

Question

我为一些虚拟功能得到了一个未解决的链接错误。 我有一个接口IFieldManager，我使用ImplFieldManager实现它。

所以我有两个需要实现的功能FieldToArea()和FieldToPoi()。已经实施。

完整的错误消息：

Severity    Code    Description Project File    Line    Suppression State
Error   LNK2001 unresolved external symbol "public: virtual bool __thiscall ImplFieldManager::FieldToArea(struct S3W::IField const &,struct S3W::IArea &)" (?FieldToArea@ImplFieldManager@@UAE_NABUIField@S3W@@AAUIArea@3@@Z)   Schiebel3DWorld (Libraries\Schiebel3DWorld\Schiebel3DWorld) D:\andre\OSGEarthLib_VS2015-build\Schiebel3DWorld\src\ImplIConnection.obj   1

我的代码：

#include "Schiebel3DWorld/include/IArea.h"
#include "Schiebel3DWorld/include/IField.h"
#include "Schiebel3DWorld/include/IPoi.h"
namespace S3W
{
    struct IFieldManager
    {
        IFieldManager() {}
        virtual ~IFieldManager() {}
        virtual bool FieldToArea(const IField& areas, IArea& manager) = 0;
        virtual bool FieldToPoi(const IField& areas, IPoi& manager) = 0;
    };
}


namespace S3W
{
struct IFieldManager;

struct IServerConnection : public CImplRefPtr, virtual public IRefPtr
{  


   virtual IFieldManager* GetFieldManager() = 0;
};

}

namespace S3W
{

struct ImplConnection : public S3W::IServerConnection, public SNet::SThread

{
    // Inherited via IServerConnection
    virtual S3W::IFieldManager * GetFieldManager() override;

};

}


#include "Schiebel3DWorld/include/IFieldManager.h"

struct ImplFieldManager : public S3W::IFieldManager
{
    ImplFieldManager(){}
    ~ImplFieldManager() {}

    // Inherited via IFieldManager
    virtual bool FieldToArea(const S3W::IField & areas, S3W::IArea & manager) override;
    virtual bool FieldToPoi(const  S3W::IField & areas, S3W::IPoi & manager) override;
};


S3W::IFieldManager * S3W::ImplConnection::GetFieldManager()
{
    return new ImplFieldManager();
}



#include "ImplFieldManager.h"


bool ImplFieldManager::FieldToArea(const  S3W::IField & areas, S3W::IArea & manager)
{
    return false;
}

bool ImplFieldManager::FieldToPoi(const  S3W::IField & areas, S3W::IPoi & manager)
{
    return false;
}