在ArcEngine中建立記憶體圖層

在ArcEngine中建立記憶體圖層[轉] 2008-04-29 10:43

arcEngine9.2中新增了一個新的特征，允許建立記憶體工作空間。當你需要一個這樣的圖層時,這個圖層的屬性資料或者幾何資料需要頻繁的更新，而又不希望是以而帶來效率上的問題，你就可以考慮使用記憶體圖層。         記憶體圖層的建立分為五步：       1、設定屬性字段       2、設定空間參考和幾何字段       3、建立記憶體工作空間       4、在記憶體工作空間中建立特征類       5、建立特征圖層，并将上一步建立的特征類設定為這個特征的圖層的特征類 請看以下完整的示例代碼         /// <summary>         /// 在記憶體中建立圖層         /// </summary>         /// <param name="DataSetName">資料集名稱</param>         /// <param name="AliaseName">别名</param>         /// <param name="SpatialRef">空間參考</param>         /// <param name="GeometryType">幾何類型</param>         /// <param name="PropertyFields">屬性字段集合</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;         }       傳回來的這個特征圖層就是我們所需要的結果，操作這個記憶體圖層方式和操作實體圖層方式完全一樣。接下要做的事情就不必我說了吧。 聯結：http://hi.baidu.com/murphy1314/blog/item/b4cdfa113710847bca80c42c.html