How to setup, solve, and save a network analysis problem

Setting up, solving, and saving a network analysis layer

1. Set up your network dataset. This code works for a File Geodatabase. You will need to set up your network dataset slightly differently for other types of datasets.  To open other types of network datasets, see How to open a network dataset:

var workspaceFactory=Activator.CreateInstance(Type.GetTypeFromProgID(
    "esriDataSourcesGDB.FileGDBWorkspaceFactory"))as IWorkspaceFactory;
var featureWorkspace=workspaceFactory.OpenFromFile(pathToWorkspace, 0)as
    IFeatureWorkspace;
var fdExtensionContainer=featureWorkspace.OpenFeatureDataset(featureDatasetName)as
    IFeatureDatasetExtensionContainer;
var datasetContainer=fdExtensionContainer.FindExtension
    (esriDatasetType.esriDTNetworkDataset)as IDatasetContainer2;
var networkDataset=datasetContainer.get_DatasetByName
    (esriDatasetType.esriDTNetworkDataset, networkDatasetName)as INetworkDataset;
var deNetworkDataset=((IDatasetComponent)networkDataset).DataElement as
    IDENetworkDataset;

Dim workspaceFactory=TryCast(Activator.CreateInstance(Type.GetTypeFromProgID("esriDataSourcesGDB.FileGDBWorkspaceFactory")), IWorkspaceFactory)
Dim featureWorkspace=TryCast(workspaceFactory.OpenFromFile(pathToWorkspace, 0), IFeatureWorkspace)
Dim fdExtensionContainer=TryCast(featureWorkspace.OpenFeatureDataset(featureDatasetName), IFeatureDatasetExtensionContainer)
Dim datasetContainer=TryCast(fdExtensionContainer.FindExtension(esriDatasetType.esriDTNetworkDataset), IDatasetContainer2)
Dim networkDataset=TryCast(datasetContainer.get_DatasetByName(esriDatasetType.esriDTNetworkDataset, networkDatasetName), INetworkDataset)
Dim deNetworkDataset=TryCast(DirectCast(networkDataset, IDatasetComponent).DataElement, IDENetworkDataset)

var routeSolver=new NARouteSolverClass()as INASolver;
INASolverSettings naSolverSettings=routeSolver as INASolverSettings;
naSolverSettings.ImpedanceAttributeName=impedanceAttributeName;

Dim routeSolver=TryCast(New NARouteSolverClass(), INASolver)
Dim naSolverSettings As INASolverSettings=TryCast(routeSolver, INASolverSettings)
naSolverSettings.ImpedanceAttributeName=impedanceAttributeName

var context=routeSolver.CreateContext(deNetworkDataset, "Name Your Context Here")
    as INAContext;
var contextEdit=context as INAContextEdit;
IGPMessages gpMessages=new GPMessagesClass();
contextEdit.Bind(networkDataset, gpMessages);

Dim context=TryCast(routeSolver.CreateContext(deNetworkDataset, "Name Your Context Here"), INAContext)
Dim contextEdit=TryCast(context, INAContextEdit)
Dim gpMessages As IGPMessages=New GPMessagesClass()
contextEdit.Bind(networkDataset, gpMessages)

var inputStopsFClass=featureWorkspace.OpenFeatureClass(inputStopsFeatureClassName);
var cursor=inputStopsFClass.Search(null, false)as ICursor;
var classLoader=new NAClassLoaderClass()as INAClassLoader;
classLoader.NAClass=context.NAClasses.get_ItemByName("Stops")as INAClass;
classLoader.Locator=context.Locator;

// Prevent locations from being placed on restricted elements
ESRI.ArcGIS.NetworkAnalyst.INALocator3 naLocator3=classLoader.Locator as
    ESRI.ArcGIS.NetworkAnalyst.INALocator3;
naLocator3.ExcludeRestrictedElements=true;
naLocator3.CacheRestrictedElements(context);

int rowsInCursor=0;
int rowsLocated=0;
classLoader.Load(cursor, null, ref rowsInCursor, ref rowsLocated);

Dim inputStopsFClass=featureWorkspace.OpenFeatureClass(inputStopsFeatureClassName)
Dim cursor=TryCast(inputStopsFClass.Search(Nothing, False), ICursor)
Dim classLoader=TryCast(New NAClassLoaderClass(), INAClassLoader)
classLoader.NAClass=TryCast(context.NAClasses.get_ItemByName("Stops"), INAClass)
classLoader.Locator=context.Locator
' Prevent locations from being placed on restricted elements
Dim naLocator3 As ESRI.ArcGIS.NetworkAnalyst.INALocator3=TryCast(classLoader.Locator, ESRI.ArcGIS.NetworkAnalyst.INALocator3)
naLocator3.ExcludeRestrictedElements=True
naLocator3.CacheRestrictedElements(context)
Dim rowsInCursor As Integer=0
Dim rowsLocated As Integer=0
classLoader.Load(cursor, Nothing, rowsInCursor, rowsLocated)

bool partialSolution=routeSolver.Solve(context, gpMessages, null);

Dim partialSolution As Boolean=routeSolver.Solve(context, gpMessages, Nothing)

var routesClass=context.NAClasses.get_ItemByName("Routes")as IFeatureClass;

Dim routesClass=TryCast(context.NAClasses.get_ItemByName("Routes"), IFeatureClass)

try
{
    INALayer3 naLayer=routeSolver.CreateLayer(context)as INALayer3;
    ILayerFile layerfile=new LayerFileClass();
    layerfile.New(outputFile);
    layerfile.ReplaceContents(naLayer as ILayer);
    layerfile.Save();
    layerfile.Close();
}

catch (Exception e)
{
    // Check here if there was an error when saving your layer file.
}

Try
Dim naLayer As INALayer3=TryCast(routeSolver.CreateLayer(context), INALayer3)
Dim layerfile As ILayerFile=New LayerFileClass()
layerfile.[New](outputFile)
layerfile.ReplaceContents(TryCast(naLayer, ILayer))
layerfile.Save()
layerfile.Close()
Catch e As Exception
' Check here if there was an error when saving your layer file.
End Try

public void SimpleRouteSetupSolveAndSaveWorkflow(string pathToWorkspace, string
    featureDatasetName, string networkDatasetName, string inputStopsFeatureClassName,
    string impedanceAttributeName, string outputFile)
{
    // Set up your network dataset.
    // This works for a FileGDB. You will need to set up your network dataset slightly differently for other types of datasets.
    // There is a document about how to open network datasets. Find that for how to open other types.
    var workspaceFactory=Activator.CreateInstance(Type.GetTypeFromProgID(
        "esriDataSourcesGDB.FileGDBWorkspaceFactory"))as IWorkspaceFactory;
    var featureWorkspace=workspaceFactory.OpenFromFile(pathToWorkspace, 0)as
        IFeatureWorkspace;
    var fdExtensionContainer=featureWorkspace.OpenFeatureDataset
        (featureDatasetName)as IFeatureDatasetExtensionContainer;
    var datasetContainer=fdExtensionContainer.FindExtension
        (esriDatasetType.esriDTNetworkDataset)as IDatasetContainer2;
    var networkDataset=datasetContainer.get_DatasetByName
        (esriDatasetType.esriDTNetworkDataset, networkDatasetName)as INetworkDataset;
    var deNetworkDataset=((IDatasetComponent)networkDataset).DataElement as
        IDENetworkDataset;

    // Set up your solver.
    var routeSolver=new NARouteSolverClass()as INASolver;
    INASolverSettings naSolverSettings=routeSolver as INASolverSettings;
    naSolverSettings.ImpedanceAttributeName=impedanceAttributeName;

    // Set up your context by creating it, then binding it to a network dataset.
    var context=routeSolver.CreateContext(deNetworkDataset, 
        "Name Your Context Here")as INAContext;
    var contextEdit=context as INAContextEdit;
    IGPMessages gpMessages=new GPMessagesClass();
    contextEdit.Bind(networkDataset, gpMessages);

    // Load new stops using the input feature class and a NAClassLoader.
    // This assumes that your input stops are from the same workspace.
    // There is also a document showing how to accomplish different kinds of loading in the SDK.
    // Check that document for information on single input and batch loading, load settings, and polygon and polyline loading.
    var inputStopsFClass=featureWorkspace.OpenFeatureClass
        (inputStopsFeatureClassName);
    var cursor=inputStopsFClass.Search(null, false)as ICursor;
    var classLoader=new NAClassLoaderClass()as INAClassLoader;
    classLoader.NAClass=context.NAClasses.get_ItemByName("Stops")as INAClass;
    classLoader.Locator=context.Locator;
    int rowsInCursor=0;
    int rowsLocated=0;
    classLoader.Load(cursor, null, ref rowsInCursor, ref rowsLocated);

    // Solve the route using current settings.
    // If you are getting an exception, put a Try-Catch around the Solve call and look at the 
    // GPMessages for specific information as to the cause of the failure.
    // You can also check the GPMessages after a successful solve to see if there are any warning or informational messages.
    bool partialSolution=routeSolver.Solve(context, gpMessages, null);

    // Get the FeatureClass containing the route results.
    // Iterate over the route class features' attribute values to examine the results.
    var routesClass=context.NAClasses.get_ItemByName("Routes")as IFeatureClass;

    // Save your solved route as a layer file.
    // Be sure that your output file ends with the extension .lyr.
    try
    {
        INALayer3 naLayer=routeSolver.CreateLayer(context)as INALayer3;
        ILayerFile layerfile=new LayerFileClass();
        layerfile.New(outputFile);
        layerfile.ReplaceContents(naLayer as ILayer);
        layerfile.Save();
        layerfile.Close();
    }
    catch (Exception e)
    {
        // Check here if there was an error when saving your layer file.
    }
}

Public Sub SimpleRouteSetupSolveAndSaveWorkflow(ByVal pathToWorkspace As String, ByVal featureDatasetName As String, ByVal networkDatasetName As String, ByVal inputStopsFeatureClassName As String, ByVal impedanceAttributeName As String, ByVal outputFile As String)
    ' Set up your network dataset.
    ' This works for a FileGDB. You will need to set up your network dataset slightly differently for other types of datasets.
    ' There is a document about how to open network datasets. Find that for how to open other types.
    Dim workspaceFactory=TryCast(Activator.CreateInstance(Type.GetTypeFromProgID("esriDataSourcesGDB.FileGDBWorkspaceFactory")), IWorkspaceFactory)
    Dim featureWorkspace=TryCast(workspaceFactory.OpenFromFile(pathToWorkspace, 0), IFeatureWorkspace)
    Dim fdExtensionContainer=TryCast(featureWorkspace.OpenFeatureDataset(featureDatasetName), IFeatureDatasetExtensionContainer)
    Dim datasetContainer=TryCast(fdExtensionContainer.FindExtension(esriDatasetType.esriDTNetworkDataset), IDatasetContainer2)
    Dim networkDataset=TryCast(datasetContainer.get_DatasetByName(esriDatasetType.esriDTNetworkDataset, networkDatasetName), INetworkDataset)
    Dim deNetworkDataset=TryCast(DirectCast(networkDataset, IDatasetComponent).DataElement, IDENetworkDataset)
    
    ' Set up your solver.
    Dim routeSolver=TryCast(New NARouteSolverClass(), INASolver)
    Dim naSolverSettings As INASolverSettings=TryCast(routeSolver, INASolverSettings)
    naSolverSettings.ImpedanceAttributeName=impedanceAttributeName
    
    ' Set up your context by creating it, then binding it to a network dataset.
    Dim context=TryCast(routeSolver.CreateContext(deNetworkDataset, "Name Your Context Here"), INAContext)
    Dim contextEdit=TryCast(context, INAContextEdit)
    Dim gpMessages As IGPMessages=New GPMessagesClass()
    contextEdit.Bind(networkDataset, gpMessages)
    
    ' Load new stops using the input feature class and a NAClassLoader.
    ' This assumes that your input stops are from the same workspace.
    ' There is also a document showing how to accomplish different kinds of loading in the SDK.
    ' Check that document for information on single input and batch loading, load settings, and polygon and polyline loading.
    Dim inputStopsFClass=featureWorkspace.OpenFeatureClass(inputStopsFeatureClassName)
    Dim cursor=TryCast(inputStopsFClass.Search(Nothing, False), ICursor)
    Dim classLoader=TryCast(New NAClassLoaderClass(), INAClassLoader)
    classLoader.NAClass=TryCast(context.NAClasses.get_ItemByName("Stops"), INAClass)
    classLoader.Locator=context.Locator
    Dim rowsInCursor As Integer=0
    Dim rowsLocated As Integer=0
    classLoader.Load(cursor, Nothing, rowsInCursor, rowsLocated)
    
    ' Solve the route using current settings.
    ' If you are getting an exception, put a Try-Catch around the Solve call and look at the
    ' GPMessages for specific information as to the cause of the failure.
    ' You can also check the GPMessages after a successful solve to see if there are any warning or informational messages.
    Dim partialSolution As Boolean=routeSolver.Solve(context, gpMessages, Nothing)
    
    ' Get the FeatureClass containing the route results.
    ' Iterate over the route class features' attribute values to examine the results.
    Dim routesClass=TryCast(context.NAClasses.get_ItemByName("Routes"), IFeatureClass)
    
    ' Save your solved route as a layer file.
    ' Be sure that your output file ends with the extension .lyr.
    Try
    Dim naLayer As INALayer3=TryCast(routeSolver.CreateLayer(context), INALayer3)
    Dim layerfile As ILayerFile=New LayerFileClass()
    layerfile.[New](outputFile)
    layerfile.ReplaceContents(TryCast(naLayer, ILayer))
    layerfile.Save()
    layerfile.Close()
    Catch e As Exception
    ' Check here if there was an error when saving your layer file.
    End Try
End Sub

See Also:

• ESRI.ArcGIS.Carto
• ESRI.ArcGIS.NetworkAnalyst
• ESRI.ArcGIS.Geodatabase
• ESRI.ArcGIS.System (ESRI.ArcGIS.esriSystem)