AcDbGroup

Class Hierarchy

AcRxObject
    AcGiDrawable
        AcDbObject
            AcDbGroup

C++

class AcDbGroup : public AcDbObject;

File

dbgroup.h

Description

The AcDbGroup class represents a collection of entities referred to by a single name. All AcDbGroup objects belong to a dictionary object which can be obtained through the AcDbDatabase::getGroupDictionary() method.

Unlike a block, entities within a group can be individually manipulated.

This class contains a dynamic array of object IDs that are the objects in the group.

Remarks

AcDbGroup plants persistent reactors on its entries when the entries are added to the group. To accomplish this, it must have an objectId. When the group is added to the group dictionary, it is also added to the database, and thus it obtains an objectId. Therefore, do not attempt to add entries to a newly created group before adding the group to the group dictionary.

For example, the code for creating a group should be similar to:

AcDbGroup *pGroup = new AcDbGroup;
AcDbObjectId  groupObjectId;
AcDbDictionary  *pGroupDict = NULL;
acdbCurDwg()->getGroupDictionary(pGroupDict, AcDb::kForWrite);
pGroupDict->setAt("GroupName", pGroup, groupObjectId);
pGroupDict->close();

pGroup->append(objectId1);     // objectId1 and objectId2
                                                 // are objId's of the
pGroup->append(objectId2);     // entities which will be in the group.

pGroup->close();

In addition, AcDbGroup's pointer cannot be closed until all of its iterators have been deleted.

Links

AcDbGroup Constructor, AcDbGroup Methods