ArcGIS Engine检索要素集、要素类和要素

        /// <summary>        /// 获取所有要素集        /// </summary>        /// <param name="workspace">工作空间对象</param>        /// <returns>要素集列表</returns>        public static List<IFeatureDataset> GetAllFeatureClass(IWorkspace workspace)        {            IEnumDataset dataset = workspace.get_Datasets(esriDatasetType.esriDTFeatureDataset);            IFeatureDataset featureDataset = dataset.Next() as IFeatureDataset;            List<IFeatureDataset> featureDatasetList = new List<IFeatureDataset>();            while (featureDataset != null)            {                featureDatasetList.Add(featureDataset);                featureDataset = dataset.Next() as IFeatureDataset;            }            return featureDatasetList;        }

        /// <summary>        /// 获取所有要素类        /// </summary>        /// <param name="featureDataset">要素集</param>        /// <returns>要素类列表</returns>        public static List<IFeatureClass> GetAllFeatureClass(IFeatureDataset featureDataset)        {            IFeatureClassContainer featureClassContainer = (IFeatureClassContainer)featureDataset;            IEnumFeatureClass enumFeatureClass = featureClassContainer.Classes;            IFeatureClass featureClass = enumFeatureClass.Next();            List<IFeatureClass> featureClassList = new List<IFeatureClass>();            while (featureClass != null)            {                featureClassList.Add(featureClass);                featureClass = enumFeatureClass.Next();            }            return featureClassList;        }

        /// <summary>        /// 获取所有要素        /// </summary>        /// <param name="featureClass">要素类</param>        /// <returns>要素列表</returns>        public static List<IFeature> GetAllFeatureClass(IFeatureClass featureClass)        {            List<IFeature> featureList = new List<IFeature>();            IFeatureCursor featureCursor = featureClass.Search(null, false);            IFeature feature = featureCursor.NextFeature();            while (feature != null)            {                featureList.Add(feature);                feature = featureCursor.NextFeature();            }            return featureList;        }