【IT168技术文档】
arcEngine9.2中新增了一个新的特征，允许创建内存工作空间。当你需要一个这样的图层时,这个图层的属性数据或者几何数据需要频繁的更新，而又不希望因此而带来效率上的问题，你就可以考虑使用内存图层。
内存图层的创建分为五步：
1、设置属性字段
2、设置空间参考和几何字段
3、创建内存工作空间
4、在内存工作空间中创建特征类
5、创建特征图层，并将上一步创建的特征类设置为这个特征的图层的特征类
请看以下完整的示例代码
返回来的这个特征图层就是我们所需要的结果，操作这个内存图层方式和操作物理图层方式完全一样。接下要做的事情就不必我说了吧。/// <summary> /// 在内存中创建图层 /// </summary> /// <param name="DataSetName">数据集名称</param> /// <param name="AliaseName">别名</param> /// <param name="SpatialRef">空间参考</param> /// <param name="GeometryType">几何类型</param> /// <param name="PropertyFields">属性字段集合</param> /// <returns>IfeatureLayer</returns> public static IFeatureLayer CreateFeatureLayerInmemeory(string DataSetName, string AliaseName, ISpatialReference SpatialRef, esriGeometryType GeometryType, IFields PropertyFields) { IWorkspaceFactory workspaceFactory = new InMemoryWorkspaceFactoryClass(); ESRI.ArcGIS.Geodatabase.IWorkspaceName workspaceName = workspaceFactory.Create("", "MyWorkspace", null, 0); ESRI.ArcGIS.esriSystem.IName name = (IName)workspaceName; ESRI.ArcGIS.Geodatabase.IWorkspace inmemWor = (IWorkspace)name.Open(); IField oField = new FieldClass(); IFields oFields = new FieldsClass(); IFieldsEdit oFieldsEdit = null; IFieldEdit oFieldEdit = null; IFeatureClass oFeatureClass = null; IFeatureLayer oFeatureLayer = null; try { oFieldsEdit = oFields as IFieldsEdit; oFieldEdit = oField as IFieldEdit; for (int i = 0; i < PropertyFields.FieldCount; i++) { oFieldsEdit.AddField(PropertyFields.get_Field(i)); } IGeometryDef geometryDef = new GeometryDefClass(); IGeometryDefEdit geometryDefEdit = (IGeometryDefEdit)geometryDef; geometryDefEdit.AvgNumPoints_2 = 5; geometryDefEdit.GeometryType_2 = GeometryType; geometryDefEdit.GridCount_2 = 1; geometryDefEdit.HasM_2 = false; geometryDefEdit.HasZ_2 = false; geometryDefEdit.SpatialReference_2 = SpatialRef; oFieldEdit.Name_2 = "SHAPE"; oFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry; oFieldEdit.GeometryDef_2 = geometryDef; oFieldEdit.IsNullable_2 = true; oFieldEdit.Required_2 = true; oFieldsEdit.AddField(oField); oFeatureClass = (inmemWor as IFeatureWorkspace).CreateFeatureClass(DataSetName, oFields, null, null, esriFeatureType.esriFTSimple, "SHAPE", ""); (oFeatureClass as IDataset).BrowseName = DataSetName; oFeatureLayer = new FeatureLayerClass(); oFeatureLayer.Name = AliaseName; oFeatureLayer.FeatureClass = oFeatureClass; } catch { } finally { try { System.Runtime.InteropServices.Marshal.ReleaseComObject(oField); System.Runtime.InteropServices.Marshal.ReleaseComObject(oFields); System.Runtime.InteropServices.Marshal.ReleaseComObject(oFieldsEdit); System.Runtime.InteropServices.Marshal.ReleaseComObject(oFieldEdit); System.Runtime.InteropServices.Marshal.ReleaseComObject(name); System.Runtime.InteropServices.Marshal.ReleaseComObject(workspaceFactory); System.Runtime.InteropServices.Marshal.ReleaseComObject(workspaceName); System.Runtime.InteropServices.Marshal.ReleaseComObject(inmemWor); System.Runtime.InteropServices.Marshal.ReleaseComObject(oFeatureClass); } catch { } GC.Collect(); } return oFeatureLayer; }
