AcDbObjectId PostToModelSpace(AcDbEntity *pEnt)
{
    //定义块表
    AcDbBlockTable *pBlk;
    acdbHostApplicationServices()->workingDatabase()->getSymbolTable(pBlk,AcDb::kForRead);
    //定义块表记录
    AcDbBlockTableRecord *pBlkTblRcd;
    pBlk->getAt(ACDB_MODEL_SPACE,pBlkTblRcd,AcDb::kForWrite);
    pBlk->close();
    //定义ID
    AcDbObjectId id;
    pBlkTblRcd->appendAcDbEntity(id,pEnt);
    pEnt->close();
    return id;
}