void GetAllLayerName()
    {
        // 读方式打开层表对象
        McDbLayerTablePointer spLayerTabl(acdbCurDwg(),McDb::kForRead);
        if(spLayerTabl.openStatus() != Mcad::eOk)
            return;

        // 创建一个遍历器，准备遍历块表

        McDbLayerTableIterator* pIterator = NULL;
        spLayerTabl->newIterator(pIterator);

        if(pIterator == NULL)
            return;
        // 把遍历器的指针交给智能指针管理
        std::auto_ptr<McDbLayerTableIterator> spIterator(pIterator);

        // 遍历所有记录

        for(;!pIterator->done();pIterator->step())
        {
            McDbObjectId id;
            pIterator->getRecordId(id);

            // 读方式打开记录
            McDbObjectPointer<McDbLayerTableRecord> spLayerRec(id,McDb::kForRead);
            if(spLayerRec.openStatus() != Mcad::eOk)
                continue;
            LPCTSTR pszName = NULL;
            spLayerRec->getName(pszName);

            CString sT;
            sT.Format(_T("发现层名:%s"),pszName);
            AfxMessageBox(sT);
        }
    };

    void CTestCommands::TestOpenAllLayer()
    {
        AcDbLayerTablePointer spLayerTable(acdbHostApplicationServices()->workingDatabase(),
            AcDb::kForRead);
        if(spLayerTable.openStatus() != Acad::eOk)
            return;

        AcDbLayerTableIterator* pLayerIter = NULL;
        spLayerTable->newIterator(pLayerIter);
        if(pLayerIter != NULL)
        {
            for(pLayerIter->start();!pLayerIter->done();pLayerIter->step())
            {
                McDbLayerTableRecord* pRecord = NULL;
                pLayerIter->getRecord(pRecord,AcDb::kForWrite);
                if(pRecord != NULL)
                {
                    pRecord->setIsOff(false);
                    pRecord->close();
                }
            }
            delete pLayerIter;
        }
    }

void DeleteAllForLayer(McDbObjectId layerId)
{
    // 由id得到图层名.
    CString sName = MrxDbgUtils::getSymbolTableRecordName(layerId);
    if(sName.IsEmpty())
        return;

    // 设置过滤条件，把图层名当着过滤条件.
    MrxDbgRbList spFilter = Mx::mcutBuildList(8,sName,0);
    MrxDbgSelSet ss;

    // 选择指定图层上的所有实体.
    ss.allSelect(spFilter.data());

    McDbObjectIdArray aryId;
    ss.asArray(aryId);

    // 循环删除实体。

    for(int i  = 0; i < aryId.length();i++)
    {
        McDbObjectPointer<McDbEntity> spEntity(aryId[i],McDb::kForWrite);
        if(spEntity.openStatus() != Mcad::eOk)
            continue;

        spEntity->erase();
    }

}