创建简单实体

下面的示例演示如何创建一行并将其追加到模型空间块表记录，如数据库入门中所述。

AcDbObjectId createLine()
{
    AcGePoint3d startPt(4.0, 2.0, 0.0);
    AcGePoint3d endPt(10.0, 7.0, 0.0);
    AcDbLine *pLine = new AcDbLine(startPt, endPt);
    AcDbBlockTable *pBlockTable;
    acdbHostApplicationServices()->workingDatabase()
        ->getSymbolTable(pBlockTable, AcDb::kForRead);
    AcDbBlockTableRecord *pBlockTableRecord;
    pBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord,
        AcDb::kForWrite);
    pBlockTable->close();
    AcDbObjectId lineId;
    pBlockTableRecord->appendAcDbEntity(lineId, pLine);
    pBlockTableRecord->close();
    pLine->close();
    return lineId;
}