objectarx二次开发自定义实体，实体数据是一个结构体tag，结构体tag中包含另外一个结构体map、一个类指针Class*、一个bool,而结构体map保存的是一个long long int数据和一个vector<wstring>.类指针class中有一个vector<class2*>, class2是个基类,使用时会根据class中的int型的参数判断强制转换成不同子类进行绘制，子类中的数据也不相同，class2中包含了vector<AcGePoint3D>以及字符串、int等数据，请问如何保存读取这些数据到dwg

为了保存自定义实体及其数据到DWG文件中，您需要使用AutoCAD提供的ObjectARX API进行开发。下面是大致的步骤： 1. 定义自定义实体类，其中包含tag结构体、Class类指针、bool变量等成员变量。 ```cpp class MyEntity : public AcDbEntity { public: ACDB_DECLARE_MEMBERS(MyEntity); MyEntity(); virtual ~MyEntity(); // Overridden methods from AcDbEntity virtual Adesk::Boolean subWorldDraw(AcGiWorldDraw* pWd); virtual Acad::ErrorStatus dwgOutFields(AcDbDwgFiler* pFiler) const; virtual Acad::ErrorStatus dwgInFields(AcDbDwgFiler* pFiler); private: tag m_tag; Class* m_pClass; bool m_bFlag; }; ``` 2. 在实体类中实现`dwgOutFields`和`dwgInFields`方法，用于保存和读取实体数据到DWG文件中。 ```cpp Acad::ErrorStatus MyEntity::dwgOutFields(AcDbDwgFiler* pFiler) const { Acad::ErrorStatus es = AcDbEntity::dwgOutFields(pFiler); if (es != Acad::eOk) return es; // Write tag data pFiler->writeInt32(m_tag.map.size()); for (auto it = m_tag.map.begin(); it != m_tag.map.end(); ++it) { pFiler->writeInt64(it->first); pFiler->writeInt32(it->second.size()); for (const auto& str : it->second) { pFiler->writeBChunk(str.c_str(), str.size() * sizeof(wchar_t)); } } pFiler->writeInt64(reinterpret_cast<AcDbUIntPtr>(m_tag.ClassPtr)); pFiler->writeBool(m_tag.bFlag); // Write Class data pFiler->writeInt32(m_pClass->vec2.size()); for (const auto& pClass2 : m_pClass->vec2) { pFiler->writeInt32(pClass2->getType()); // Save type information pFiler->writeBChunk(&pClass2->ptVec[0], pClass2->ptVec.size() * sizeof(AcGePoint3d)); pFiler->writeBChunk(pClass2->str.c_str(), pClass2->str.size() * sizeof(wchar_t)); pFiler->writeInt32(pClass2->n); } return pFiler->filerStatus(); } Acad::ErrorStatus MyEntity::dwgInFields(AcDbDwgFiler* pFiler) { Acad::ErrorStatus es = AcDbEntity::dwgInFields(pFiler); if (es != Acad::eOk) return es; // Read tag data int nSize = 0; pFiler->readInt32(&nSize); for (int i = 0; i < nSize; ++i) { long long llKey = 0; pFiler->readInt64(&llKey); int nVecSize = 0; pFiler->readInt32(&nVecSize); std::vector<std::wstring> vecStr; for (int j = 0; j < nVecSize; ++j) { char* pBuf = nullptr; int nLen = 0; pFiler->readBChunk(&pBuf, &nLen); vecStr.emplace_back(reinterpret_cast<wchar_t*>(pBuf), nLen / sizeof(wchar_t)); acutDelString(pBuf); } m_tag.map[llKey] = vecStr; } AcDbUIntPtr nPtr = 0; pFiler->readInt64(reinterpret_cast<AcDbUIntPtr*>(&nPtr)); m_tag.ClassPtr = reinterpret_cast<Class*>(nPtr); pFiler->readBool(&m_tag.bFlag); // Read Class data pFiler->readInt32(&nSize); for (int i = 0; i < nSize; ++i) { int nType = 0; pFiler->readInt32(&nType); class2* pClass2 = nullptr; if (nType == 1) { pClass2 = new class2A; } else if (nType == 2) { pClass2 = new class2B; } else { // Unknown type, skip continue; } char* pBuf = nullptr; int nLen = 0; pFiler->readBChunk(&pClass2->ptVec[0], pClass2->ptVec.size() * sizeof(AcGePoint3d)); pFiler->readBChunk(&pBuf, &nLen); pClass2->str = std::wstring(reinterpret_cast<wchar_t*>(pBuf), nLen / sizeof(wchar_t)); acutDelString(pBuf); pFiler->readInt32(&pClass2->n); m_pClass->vec2.emplace_back(pClass2); } return pFiler->filerStatus(); } ``` 3. 在自定义实体的构造函数中初始化成员变量。 ```cpp MyEntity::MyEntity() { m_tag.ClassPtr = nullptr; m_tag.bFlag = false; m_pClass = new Class; } ``` 4. 在实体类中实现`subWorldDraw`方法，用于绘制实体。 ```cpp Adesk::Boolean MyEntity::subWorldDraw(AcGiWorldDraw* pWd) { // Draw entity using OpenGL // ... // Draw Class data for (const auto& pClass2 : m_pClass->vec2) { if (auto pClass2A = dynamic_cast<class2A*>(pClass2)) { // Draw class2A using OpenGL // ... } else if (auto pClass2B = dynamic_cast<class2B*>(pClass2)) { // Draw class2B using OpenGL // ... } else { // Unknown type, skip continue; } } return Adesk::kTrue; } ``` 在AutoCAD中使用自定义实体时，可以使用下列代码进行创建并添加到当前图形数据库中： ```cpp MyEntity* pEnt = new MyEntity; AcDbObjectId objId; Acad::ErrorStatus es = acdbHostApplicationServices()->workingDatabase()->addAcDbEntity(objId, pEnt); if (es == Acad::eOk) { // Set entity properties // ... // Add entity to current space AcDbBlockTableRecord* pBTR = nullptr; es = acdbHostApplicationServices()->workingDatabase()->getModelSpace(pBTR, AcDb::kForWrite); if (es == Acad::eOk) { es = pBTR->appendAcDbEntity(objId, pEnt); pBTR->close(); } } else { delete pEnt; } ``` 当从DWG文件中读取自定义实体时，可以使用下列代码进行获取： ```cpp AcDbObjectIdArray objIds; acdbGetObjectsOfType(objIds, MyEntity::desc()); for (const auto& objId : objIds) { MyEntity* pEnt = nullptr; Acad::ErrorStatus es = acdbOpenAcDbEntity(reinterpret_cast<AcDbEntity*&>(pEnt), objId, AcDb::kForRead); if (es == Acad::eOk) { // Get entity properties // ... pEnt->close(); } } ```