/// <summary>/// Services the area./// </summary>/// <param name="networkDataset">The network dataset.</param>public void ServiceArea(INetworkDataset networkDataset){log.WriteLog("开始创建ServiceArea...");IWorkspaceFactory workspaceFactory = new ShapefileWorkspaceFactoryClass();IWorkspace workspace = workspaceFactory.OpenFromFile(Functions.g_WorkSpacePath, 0);IFeatureWorkspace featureWorkspace = workspace as IFeatureWorkspace;CreateSolverContext(networkDataset);if (!LoadLocations(featureWorkspace, Functions.g_Hospital)){log.WriteLog("LoadLocations失败！");}log.WriteLog("ServiceArea创建完成！");}/// <summary>/// Geodatabase function: get network dataset/// </summary>/// <param name="networkDataset">Input network dataset</param>/// <returns>DE network dataset</returns>public IDENetworkDataset GetDENetworkDataset(INetworkDataset networkDataset){// Cast from the network dataset to the DatasetComponent
IDatasetComponent dsComponent = networkDataset as IDatasetComponent;// Get the data elementreturn dsComponent.DataElement as IDENetworkDataset;}/// <summary>/// Create NASolver and NAContext/// </summary>/// <param name="networkDataset">Input network dataset</param>private void CreateSolverContext(INetworkDataset networkDataset){if (networkDataset == null) return;//Get the Data Element
IDENetworkDataset deNDS = GetDENetworkDataset(networkDataset);INASolver naSolver = new NAServiceAreaSolverClass();m_NAContext = naSolver.CreateContext(deNDS, naSolver.Name);((INAContextEdit)m_NAContext).Bind(networkDataset, new GPMessagesClass());}/// <summary>/// Loads the locations./// </summary>/// <param name="featureWorkspace">The feature workspace.</param>/// <param name="inputFacilities">The input facilities.</param>/// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>private bool LoadLocations(IFeatureWorkspace featureWorkspace, string inputFacilities){IFeatureClass inputFeatureClass = null;try{inputFeatureClass = featureWorkspace.OpenFeatureClass(inputFacilities);}catch (Exception){log.WriteLog("Specified input feature class does not exist");return false;}INamedSet classes = m_NAContext.NAClasses;INAClass naClass = classes.get_ItemByName("Facilities") as INAClass;// delete existing locations, except barriers
naClass.DeleteAllRows();// Create a NAClassLoader and set the snap tolerance (meters unit)
INAClassLoader naClassLoader = new NAClassLoaderClass();naClassLoader.Locator = m_NAContext.Locator;((INALocator3)naClassLoader.Locator).MaxSnapTolerance = 500;naClassLoader.NAClass = naClass;// Create field map to automatically map fields from input class to NAClass
INAClassFieldMap naClassFieldMap = new NAClassFieldMapClass();naClassFieldMap.CreateMapping(naClass.ClassDefinition, inputFeatureClass.Fields);naClassLoader.FieldMap = naClassFieldMap;// Avoid loading network locations onto non-traversable portions of elements
INALocator3 locator = m_NAContext.Locator as INALocator3;locator.ExcludeRestrictedElements = true;locator.CacheRestrictedElements(m_NAContext);// load network locationsint rowsIn = 0;int rowsLocated = 0;IQueryFilter qf = new QueryFilterClass();qf.WhereClause = "aaaaaaaaaaa";  naClassLoader.Load(inputFeatureClass.Search(qf, true) as ICursor, null, ref rowsIn, ref rowsLocated);if (rowsLocated <= 0){log.WriteLog("Facilities were not loaded from input feature class");return false;}// Message all of the network analysis agents that the analysis context has changed
INAContextEdit naContextEdit = m_NAContext as INAContextEdit;naContextEdit.ContextChanged();return true;}