Arcengine创建内存工作空间，要素类（InMemoryWorkspaceFactory）

1.创建内存工作空间

public static IWorkspace CreateInMemoryWorkspace(){  // Create an in-memory workspace factory.  Type factoryType = Type.GetTypeFromProgID(    "esriDataSourcesGDB.InMemoryWorkspaceFactory");  IWorkspaceFactory workspaceFactory = (IWorkspaceFactory)    Activator.CreateInstance(factoryType);  // Create an in-memory workspace.  IWorkspaceName workspaceName = workspaceFactory.Create("", "MyWorkspace",    null, 0);  // Cast for IName and open a reference to the in-memory workspace through the name object.  IName name = (IName)workspaceName;  IWorkspace workspace = (IWorkspace)name.Open();  return workspace;}

2.创建要素类

    /// <summary>        /// 在指定的数据库中创建与源要素类相同的要素类        /// </summary>        /// <param name="pWorkspace"></param>        /// <param name="pSrcFC"></param>        /// <param name="sTargetName"></param>        /// <param name="pTargetSrf"></param>        /// <param name="sOutputFields"></param>        /// <returns></returns>        public static IFeatureClass CreateFeatureClass(IWorkspace pWorkspace,            IFeatureClass pSrcFC,            string sTargetName = null,            ISpatialReference pTargetSrf = null,            string sOutputFields = null)        {            if (string.IsNullOrEmpty(sTargetName))            {                sTargetName = (pSrcFC as IDataset).Name;            }            sTargetName = GetDatasetName(sTargetName);            DeleteDataset(pWorkspace, sTargetName);            //验证字段            IFields pFields;            string sShapeFieldName;            string sError;            CheckFields(pSrcFC, pWorkspace, out pFields, out sShapeFieldName, out sError);            //根据输出字段限制，处理字段            if (!string.IsNullOrWhiteSpace(sOutputFields))            {                IFieldsEdit pFieldsEdit = pFields as IFieldsEdit;                string[] pOutputFields = sOutputFields.Split(',');                for (int i = pFields.FieldCount - 1; i >= 0; i--)                {                    IField pField = pFields.get_Field(i);                    if (pField.Type == esriFieldType.esriFieldTypeGeometry ||                        pField.Type == esriFieldType.esriFieldTypeOID)                    {                        continue;                    }                    bool bFind = false;                    foreach (string sOutputField in pOutputFields)                    {                        if (sOutputField == pField.Name)                        {                            bFind = true;                            break;                        }                    }                    if (!bFind)                    {                        pFieldsEdit.DeleteField(pField);                    }                }            }            //修改几何字段中的空间参考信息            if (pTargetSrf != null)            {                int iIndex = pFields.FindField(sShapeFieldName);                //几何定义                IGeometryDef pGeometryDef = pFields.get_Field(iIndex).GeometryDef;                IGeometryDefEdit pGeometryDefEdit = pGeometryDef as IGeometryDefEdit;                pGeometryDefEdit.SpatialReference_2 = pTargetSrf;            }            IFeatureClass pFeatureClass = CreateFeatureClass(pWorkspace, pSrcFC,                pFields, sShapeFieldName, sTargetName, null, pTargetSrf);            return pFeatureClass;        }        /// <summary>        /// 创建要素类，考虑要素类存在要素数据集中        /// </summary>        /// <param name="pWorkspace"></param>        /// <param name="pSrcFC"></param>        /// <param name="pFields"></param>        /// <param name="sShapeFieldName"></param>        /// <param name="sTargetName"></param>        /// <param name="sAlias"></param>        /// <param name="pTargetSrf"></param>        /// <returns></returns>        public static IFeatureClass CreateFeatureClass(IWorkspace pWorkspace,            IFeatureClass pSrcFC,            IFields pFields,            string sShapeFieldName,            string sTargetName = null,            string sAlias = null,            ISpatialReference pTargetSrf = null)        {            UID CLSID = new UIDClass();            CLSID.Value = "esriGeoDatabase.Feature";            if (string.IsNullOrEmpty(sTargetName))            {                sTargetName = GetDatasetName((pSrcFC as IDataset).Name);            }            IFeatureClass pFeatureClass = null;            //是否需要创建要素数据集            IFeatureDataset pTargetDataset = GetFeatureDataset(pWorkspace, pSrcFC, pTargetSrf);            try            {                if (pSrcFC.FeatureType == esriFeatureType.esriFTAnnotation)                {                    //Anno Workspace                    IFeatureWorkspaceAnno pFWSAnno = pWorkspace as IFeatureWorkspaceAnno;                    //获得AnnoFeatureClass的显示参数units和referencescale                    IAnnoClass pAnnoClass = pSrcFC.Extension as IAnnoClass;                    IGraphicsLayerScale pGraphicsLayerScale = new GraphicsLayerScaleClass();                    pGraphicsLayerScale.Units = pAnnoClass.ReferenceScaleUnits;                    pGraphicsLayerScale.ReferenceScale = pAnnoClass.ReferenceScale;                    IObjectClassDescription pOCDesc = new AnnotationFeatureClassDescription();                    pFeatureClass = pFWSAnno.CreateAnnotationClass(sTargetName, pFields, pOCDesc.InstanceCLSID,                        pOCDesc.ClassExtensionCLSID, pSrcFC.ShapeFieldName, "", pTargetDataset,                        null, pAnnoClass.AnnoProperties, pGraphicsLayerScale,                        pAnnoClass.SymbolCollection, false);                }                else                {                    if (pTargetDataset != null)                    {                        pFeatureClass = pTargetDataset.CreateFeatureClass(sTargetName, pFields, CLSID, null, pSrcFC.FeatureType, sShapeFieldName, "");                    }                    else                    {                        pFeatureClass = (pWorkspace as IFeatureWorkspace).CreateFeatureClass(sTargetName, pFields, CLSID, null, pSrcFC.FeatureType, sShapeFieldName, "");                    }                }            }            finally            {                if (pTargetDataset != null)                {                    Marshal.ReleaseComObject(pTargetDataset);                }            }            //设置要素类别名            if (string.IsNullOrWhiteSpace(sAlias))            {                sAlias = pSrcFC.AliasName;            }            AlterDatasetAlias(pFeatureClass, sAlias);            return pFeatureClass;        }