void我只知道如何创建一个图层如下createNewLayer(){ AcDbLayerTable *pLayerTable; acdbHostApplicationServices()->workingDatabase() ->getSymbolTable(pLayerTable, AcDb::kForWrite); AcDbLayerTableRecord *pLayerTableRecord = new AcDbLayerTableRecord; pLayerTableRecord->setName("ASDK_MYLAYER"); // Defaults are used for other properties of // the layer if they are not otherwise specified. // pLayerTable->add(pLayerTableRecord); pLayerTable->close(); pLayerTableRecord->close();}但是删除已知的空图层呢