ObjectARX_AcDb2dPolyline复杂实体

1遍历：访问或者编辑复杂实体也须要经过特定的方式。

AcDb2dPolyline的顶点信息不能经过AcDb2dPolyline对象直接获得，须要遍历AcDb2dPolyline所包含的AcDb2dVertex对象:

void IteratePolyline(AcDbObject plineId)
{
//打开polyline对象
AcDb2dPolyline * pPline = NULL;
acdbOpenObject(pPline,plineId,AcDb::kForRead);

//建立顶点遍历器指针
AcDbObjectIterator *pVertIter = pPline->vertexIterator();
pPline->close();
AcDb2dVertex * pVertex = NULL;
AcGePoint3d location;
AcDbObjectId vertexObjId;

//循环遍历polyline顶点
for(int i = 0; !pVertIter->done(); i++,pVertIter->step())
{
vertexObjId = pVertIter->objectId();
acdbOpenObject(pVertex ,vertexObjId ,AcDb::kForRead);
location = pVertex ->position();
pVertex->close();
acutPrintf(_T("\顶点#%d位置：")_T(":%0.3f,%0.3f,%0.3f"),vertexNumber,location[X],location[Y],location[Z]);
}
//删除遍历器
delete pVertIter;
}

2.删除：不能只是简单的删除复杂实体对象自己，还须要先依次删除包含的子实体，再删除复杂实体对象自己，才能删除完整。

先依次删除AcDb2dPolyline所包含的顶点对象，在删除AcDb2dPolyline对象：

void delete2dPolyline(AcDb2dPolyline * pPline)
{
//建立顶点遍历器
AcDbObjectIterator * pIter = pPline->vertexIterator();
AcDbEntity * pEnt = NULL;
for(;!pIter->done();)
{
//依次删除顶点
pEnt = pIter->entity();
pIter->step();
delete pEnt;
}
//删除遍历器，删除polyLine
delete pIter;
delete pPline;
}