public override void BeginRead() { try { IUniversalVectorDataReader udr = VectorDataReaderFactory.GetUniversalDataReader(_fileUrl); _reader = udr as IVectorFeatureDataReader; _reader.SetArgsOfLeveling(_argOfLeveling); _readIsFinished = false; } finally { if (GlobalCacher.VectorDataGlobalCacher != null && GlobalCacher.VectorDataGlobalCacher.IsEnabled && GlobalCacher.VectorDataGlobalCacher.IsGllPrjOfActiveViewer) { GlobalCacher.VectorDataGlobalCacher.Request(_fileUrl); } } }