arcengine创建network dataset

• Creating a new network dataset data element
• Adding the network sources
  • Specifying the connectivity settings for the edge source
  • Specifying the directions settings for the edge source
  • Specifying the turn source
• Adding the network attributes
  • Oneway network attribute
  • Minutes network attribute
  • Meters network attribute
  • RoadClass network attribute
  • TurnRestriction network attribute
• Specifying directions settings
  • General directions settings
• Creating and building the network dataset

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Creating a new network dataset data element

The network dataset being created is based on the Paris.gdb file geodatabase data located in: C:\Program Files\ArcGIS\DeveloperKit\SamplesNET\data\CreateNetworkDataset. First, a new network dataset data element will be created, the RoadNetwork feature dataset will be opened, and its extent and spatial reference information copied to the data element. The network dataset will be named ParisNet.

This document uses the geodatabase file, Paris.gdb, which is installed in the C:\arcgis\ArcTutor\Network_Analyst\Exercise2 folder. If you have the ArcGIS Tutorial Data installed, you can modify the OpenFromFile() call in the following code to create the network dataset in that file geodatabase instead.

[VB.NET]

' Create a new empty data element for a buildable network dataset.
Dim deND As IDENetworkDataset = New DENetworkDataset
deND.Buildable = True

' Open the feature dataset and CType to the IGeoDataset interface.
Dim gdbWSF As IWorkspaceFactory = New FileGDBWorkspaceFactory
Dim gdbFWS As IFeatureWorkspace = CType(gdbWSF.OpenFromFile("C:\Program Files\ArcGIS\DeveloperKit\SamplesNET\data\CreateNetworkDataset\Paris.gdb", 0), IFeatureWorkspace)
Dim fdsGDS As IGeoDataset = CType(gdbFWS.OpenFeatureDataset("RoadNetwork"), IGeoDataset)

' Copy the feature dataset's extent and spatial reference to the network dataset data element.
Dim deGDS As IDEGeoDataset = CType(deND, IDEGeoDataset)
deGDS.Extent = fdsGDS.Extent
deGDS.SpatialReference = fdsGDS.SpatialReference

' Specify the name of the network dataset.
Dim dataElement As IDataElement = CType(deND, IDataElement)
dataElement.Name = "ParisNet"

[C#]

// Create a new empty data element for a buildable network dataset.
IDENetworkDataset deNetworkDataset = new DENetworkDatasetClass();
deNetworkDataset.Buildable = true;

// Open the feature dataset and cast to the IGeoDataset interface.
IWorkspaceFactory workspaceFactory = new FileGDBWorkspaceFactory();
IWorkspace workspace = workspaceFactory.OpenFromFile(@
    "C:\Program Files\ArcGIS\DeveloperKit\SamplesNET\data\CreateNetworkDataset\Paris.gdb", 0);
IFeatureWorkspace featureWorkspace = (IFeatureWorkspace)workspace;
IFeatureDataset featureDataset = featureWorkspace.OpenFeatureDataset("RoadNetwork");
IGeoDataset geoDataset = (IGeoDataset)featureDataset;

// Copy the feature dataset's extent and spatial reference to the network dataset data element.
IDEGeoDataset deGeoDataset = (IDEGeoDataset)deNetworkDataset;
deGeoDataset.Extent = geoDataset.Extent;
deGeoDataset.SpatialReference = geoDataset.SpatialReference;

// Specify the name of the network dataset.
IDataElement dataElement = (IDataElement)deNetworkDataset;
dataElement.Name = "ParisNet";

 

Adding the network sources

The network dataset will be created with two network sources: Streets feature class and ParisTurns feature class. The Streets feature class will become an edge source in the network dataset, and the ParisTurns feature class will become a turn source.

 

Specifying the connectivity settings for the edge source

The Streets feature class needs to be an edge feature source in the network dataset with the appropriate connectivity and directions settings. The following is from the New Network Dataset wizard's summary for the source's connectivity settings:

 

Connectivity:
  Group 1:
    Edge Connectivity:
      Streets : Highways (End Point)
      Streets : Local Streets (Any Vertex)
      Streets : Major Roads (End Point)

 

 

The subtype values for the Streets feature class are as follows:

 

Highways = 1
Major Roads = 2
Local Streets = 3

 

The following connectivity settings will be used when creating a new EdgeFeatureSource object:

[VB.NET]

' Create a new EdgeFeatureSource object and point it to the Streets feature class.
Dim edgeNetSource As INetworkSource = New EdgeFeatureSource
edgeNetSource.Name = "Streets"
edgeNetSource.ElementType = esriNETEdge

' Set the edge feature source's connectivity settings.
Dim edgeFS As IEdgeFeatureSource = CType(edgeNetSource, IEdgeFeatureSource)
With edgeFS
    .UsesSubtypes = True
    .SubtypeConnectivityGroup(1) = 1
    .SubtypeConnectivityPolicy(1) = esriNECPEndVertex
    .SubtypeConnectivityGroup(2) = 1
    .SubtypeConnectivityPolicy(2) = esriNECPEndVertex
    .SubtypeConnectivityGroup(3) = 1
    .SubtypeConnectivityPolicy(3) = esriNECPAnyVertex
End With

[C#]

// Create a new EdgeFeatureSource object and point it to the Streets feature class.
INetworkSource edgeNetworkSource = new EdgeFeatureSourceClass();
edgeNetworkSource.Name = "Streets";
edgeNetworkSource.ElementType = esriNetworkElementType.esriNETEdge;

// Set the edge feature source's connectivity settings.
IEdgeFeatureSource edgeFeatureSource = (IEdgeFeatureSource)edgeNetworkSource;
edgeFeatureSource.UsesSubtypes = true;
edgeFeatureSource.set_SubtypeConnectivityGroup(1, 1);
edgeFeatureSource.set_SubtypeConnectivityPolicy(1,
    esriNetworkEdgeConnectivityPolicy.esriNECPEndVertex);
edgeFeatureSource.set_SubtypeConnectivityGroup(2, 1);
edgeFeatureSource.set_SubtypeConnectivityPolicy(2,
    esriNetworkEdgeConnectivityPolicy.esriNECPEndVertex);
edgeFeatureSource.set_SubtypeConnectivityGroup(3, 1);
edgeFeatureSource.set_SubtypeConnectivityPolicy(3,
    esriNetworkEdgeConnectivityPolicy.esriNECPAnyVertex);

 

Specifying the directions settings for the edge source

The edge source also has settings used when generating driving directions and identifying the fields that contain the street names. The following is from the New Network Dataset wizard's summary for the source's directions settings:

 

Source Directions:
    Streets:
      Street Name Fields:
        Primary:
          Name: FULL_NAME

 

The following directions settings will be used when creating a new StreetNameFields object. This object will be added to the EdgeFeatureSource object created previously:

[VB.NET]

' Create a StreetNameFields object and populate its settings.
Dim snf As IStreetNameFields = New StreetNameFields
With snf
    .Priority = 1 'Priority 1 indicates the primary street name.
    .StreetNameFieldName = "FULL_NAME"
End With

' Add the StreetNameFields object to a new NetworkSourceDirections object,
' then add it to the EdgeFeatureSource created earlier.
Dim nsd As INetworkSourceDirections = New NetworkSourceDirections
Dim snfArray As IArray = New ESRI.ArcGIS.esriSystem.Array
snfArray.Add(snf)
nsd.StreetNameFields = snfArray
edgeNetSource.NetworkSourceDirections = nsd

[C#]

// Create a StreetNameFields object and populate its settings.
IStreetNameFields streetNameFields = new StreetNameFieldsClass();
streetNameFields.Priority = 1; // Indicates the primary street name.
streetNameFields.StreetNameFieldName = "FULL_NAME";

// Add the StreetNameFields object to a new NetworkSourceDirections object,
// then add it to the EdgeFeatureSource created earlier.
INetworkSourceDirections nsDirections = new NetworkSourceDirectionsClass();
IArray nsdArray = new ArrayClass();
nsdArray.Add(streetNameFields);
nsDirections.StreetNameFields = nsdArray;
edgeNetworkSource.NetworkSourceDirections = nsDirections;

 

Specifying the turn source

The network dataset will have a turn feature source referencing the ParisTurns feature class. Specify on the data element that the network dataset supports turns, then create the TurnFeatureSource object. See the following code:

[VB.NET]

deND.SupportsTurns = True

' Create a new TurnFeatureSource object and point it to the ParisTurns feature class.
Dim turnNetSource As INetworkSource = New TurnFeatureSource
turnNetSource.Name = "ParisTurns"
turnNetSource.ElementType = esriNETTurn

[C#]

deNetworkDataset.SupportsTurns = true;

// Create a new TurnFeatureSource object and point it to the ParisTurns feature class.
INetworkSource turnNetworkSource = new TurnFeatureSourceClass();
turnNetworkSource.Name = "ParisTurns";
turnNetworkSource.ElementType = esriNetworkElementType.esriNETTurn;

 

Now that all the sources have been created, they can be added to the array, then the array can be added to the network dataset data element. See the following code:

 

 

[VB.NET]

Dim sourceArray As IArray = New ESRI.ArcGIS.esriSystem.Array
With sourceArray
    .Add(edgeNetSource)
    .Add(turnNetSource)
End With

deND.Sources = sourceArray

[C#]

IArray sourceArray = new ArrayClass();
sourceArray.Add(edgeNetworkSource);
sourceArray.Add(turnNetworkSource);

deNetworkDataset.Sources = sourceArray;

 

Adding the network attributes

The network dataset will be created with five network attributes:

• Oneway network attribute
• Minutes network attribute
• Meters network attribute
• RoadClass network attribute
• TurnRestriction network attribute

 

An empty array for the network attributes will be created, then each attribute will be created and added to the array. See the following code:

 

[VB.NET]

Dim attrArray As IArray = New ESRI.ArcGIS.esriSystem.Array

[C#]

IArray attributeArray = new ArrayClass();

 

Oneway network attribute

The following is from the New Network Dataset wizard's summary for the Oneway network attribute:

 

Oneway:
    Usage Type: Restriction
    Data Type: Boolean
    Units Type: Unknown
    Use by Default: True
    Source Attribute Evaluators:
      Streets (From-To): Field -
          Prelogic:
            restricted = False
            Select Case UCase([Oneway])
              Case "N", "TF", "T": restricted = True
            End Select
          Expression: restricted
      Streets (To-From): Field -
          Prelogic:
            restricted = False
            Select Case UCase([Oneway])
              Case "N", "FT", "F": restricted = True
            End Select
          Expression: restricted
    Default Attribute Evaluators:
      Default Edges: Constant - Traversable
      Default Junctions: Constant - Traversable
      Default Turns: Constant - Traversable

 

See the following code:

 

[VB.NET]

' Create a new EvaluatedNetworkAttribute object and populate its settings.
Dim evalNetAttr As IEvaluatedNetworkAttribute = New EvaluatedNetworkAttribute
Dim netAttr2 As INetworkAttribute2 = CType(evalNetAttr, INetworkAttribute2)
With netAttr2
    .Name = "Oneway"
    .UsageType = esriNAUTRestriction
    .DataType = esriNADTBoolean
    .Units = esriNAUUnknown
    .UseByDefault = True
End With

' Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
Dim netFieldEval As INetworkFieldEvaluator = New NetworkFieldEvaluator
netFieldEval.SetExpression("restricted", _
                           "restricted = False" & vbNewLine & _
                           "Select Case UCase([Oneway])" & vbNewLine & _
                           "  Case ""N"", ""TF"", ""T"": restricted = True" & vbNewLine & _
                           "End Select")
evalNetAttr.Evaluator(edgeNetSource, esriNEDAlongDigitized) = netFieldEval

netFieldEval = New NetworkFieldEvaluator
netFieldEval.SetExpression("restricted", _
                           "restricted = False" & vbNewLine & _
                           "Select Case UCase([Oneway])" & vbNewLine & _
                           "  Case ""N"", ""FT"", ""F"": restricted = True" & vbNewLine & _
                           "End Select")
evalNetAttr.Evaluator(edgeNetSource, esriNEDAgainstDigitized) = netFieldEval

Dim netConstEval As INetworkConstantEvaluator = New NetworkConstantEvaluator
netConstEval.ConstantValue = False 'False means Traversable (that is, not restricted).
evalNetAttr.DefaultEvaluator(esriNETEdge) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETJunction) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETTurn) = netConstEval

' Add the attribute to the array.
attrArray.Add(evalNetAttr)

[C#]

// Create a new EvaluatedNetworkAttribute object and populate its settings.
IEvaluatedNetworkAttribute oneWayAttribute = new EvaluatedNetworkAttributeClass();
INetworkAttribute2 oneWayNetworkAttribute2 = (INetworkAttribute2)oneWayAttribute;
oneWayNetworkAttribute2.Name = "Oneway";
oneWayNetworkAttribute2.UsageType =
    esriNetworkAttributeUsageType.esriNAUTRestriction;
oneWayNetworkAttribute2.DataType = esriNetworkAttributeDataType.esriNADTBoolean;
oneWayNetworkAttribute2.Units = esriNetworkAttributeUnits.esriNAUUnknown;
oneWayNetworkAttribute2.UseByDefault = true;

// Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
INetworkFieldEvaluator oneWayToFromNetworkFieldEvaluator = new
    NetworkFieldEvaluatorClass();
INetworkEvaluator oneWayToFromNetworkEvaluator = (INetworkEvaluator)
    oneWayToFromNetworkFieldEvaluator;
oneWayToFromNetworkFieldEvaluator.SetExpression("restricted", 
    "restricted = False\n\rSelect Case UCase([Oneway])\n\r Case \"N\", \"TF\", \"T\": restricted = True\n\rEnd Select");
oneWayAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAlongDigitized, oneWayToFromNetworkEvaluator);

INetworkFieldEvaluator oneWayFromToNetworkFieldEvaluator = new
    NetworkFieldEvaluatorClass();
INetworkEvaluator oneWayFromToNetworkEvaluator = (INetworkEvaluator)
    oneWayFromToNetworkFieldEvaluator;
oneWayFromToNetworkFieldEvaluator.SetExpression("restricted", 
    "restricted = False\n\rSelect Case UCase([Oneway])\n\r Case \"N\", \"FT\", \"F\": restricted = True\n\rEnd Select");
oneWayAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAgainstDigitized, oneWayFromToNetworkEvaluator);

INetworkConstantEvaluator oneWayNetworkConstantEvaluator = new
    NetworkConstantEvaluatorClass();
INetworkEvaluator oneWayConstantNetworkEvaluator = (INetworkEvaluator)
    oneWayNetworkConstantEvaluator;
oneWayNetworkConstantEvaluator.ConstantValue = false; // False = traversable
oneWayAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETEdge,
    oneWayConstantNetworkEvaluator);
oneWayAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETJunction,
    oneWayConstantNetworkEvaluator);
oneWayAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETTurn,
    oneWayConstantNetworkEvaluator);

// Add the attribute to the array.
attributeArray.Add(oneWayAttribute);

 

Minutes network attribute

The following is from the New Network Dataset wizard's summary for the Minutes network attribute:

 

Minutes:
    Usage Type: Cost
    Data Type: Double
    Units Type: Minutes
    Use by Default: True
    Source Attribute Evaluators:
      Streets (From-To): Field - [FT_Minutes]
      Streets (To-From): Field - [TF_Minutes]
    Default Attribute Evaluators:
      Default Edges: Constant - 0
      Default Junctions: Constant - 0
      Default Turns: Constant - 0

 

See the following code:

[VB.NET]

' Create a new EvaluatedNetworkAttribute object and populate its settings.
evalNetAttr = New EvaluatedNetworkAttribute
netAttr2 = CType(evalNetAttr, INetworkAttribute2)
With netAttr2
    .Name = "Minutes"
    .UsageType = esriNAUTCost
    .DataType = esriNADTDouble
    .Units = esriNAUMinutes
    .UseByDefault = True
End With

' Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
netFieldEval = New NetworkFieldEvaluator
netFieldEval.SetExpression("[FT_Minutes]", "")
evalNetAttr.Evaluator(edgeNetSource, esriNEDAlongDigitized) = netFieldEval

netFieldEval = New NetworkFieldEvaluator
netFieldEval.SetExpression("[TF_Minutes]", "")
evalNetAttr.Evaluator(edgeNetSource, esriNEDAgainstDigitized) = netFieldEval

netConstEval = New NetworkConstantEvaluator
netConstEval.ConstantValue = 0
evalNetAttr.DefaultEvaluator(esriNETEdge) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETJunction) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETTurn) = netConstEval

' Add the attribute to the array.
attrArray.Add(evalNetAttr)

[C#]

// Create a new EvaluatedNetworkAttribute object and populate its settings.
IEvaluatedNetworkAttribute minutesAttribute = new EvaluatedNetworkAttributeClass();
INetworkAttribute2 minutesNetworkAttribute2 = (INetworkAttribute2)minutesAttribute;
minutesNetworkAttribute2.Name = "Minutes";
minutesNetworkAttribute2.UsageType = esriNetworkAttributeUsageType.esriNAUTCost;
minutesNetworkAttribute2.DataType = esriNetworkAttributeDataType.esriNADTDouble;
minutesNetworkAttribute2.Units = esriNetworkAttributeUnits.esriNAUMinutes;
minutesNetworkAttribute2.UseByDefault = true;

// Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
INetworkFieldEvaluator ftMinutesNetworkFieldEvaluator = new
    NetworkFieldEvaluatorClass();
INetworkEvaluator ftMinutesNetworkEvaluator = (INetworkEvaluator)
    ftMinutesNetworkFieldEvaluator;
ftMinutesNetworkFieldEvaluator.SetExpression("[FT_Minutes]", "");
minutesAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAlongDigitized, ftMinutesNetworkEvaluator);

INetworkFieldEvaluator tfMinutesNetworkFieldEvaluator = new
    NetworkFieldEvaluatorClass();
INetworkEvaluator tfMinutesNetworkEvaluator = (INetworkEvaluator)
    tfMinutesNetworkFieldEvaluator;
tfMinutesNetworkFieldEvaluator.SetExpression("[TF_Minutes]", "");
minutesAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAgainstDigitized, tfMinutesNetworkEvaluator);

INetworkConstantEvaluator minutesNetworkConstantEvaluator = new
    NetworkConstantEvaluatorClass();
INetworkEvaluator minutesConstantNetworkEvaluator = (INetworkEvaluator)
    minutesNetworkConstantEvaluator;
minutesNetworkConstantEvaluator.ConstantValue = 0;
minutesAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETEdge,
    minutesConstantNetworkEvaluator);
minutesAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETJunction,
    minutesConstantNetworkEvaluator);
minutesAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETTurn,
    minutesConstantNetworkEvaluator);

// Add the attribute to the array.
attributeArray.Add(minutesAttribute);

 

Meters network attribute

The following is from the New Network Dataset wizard's summary for the Meters network attribute:

 

Meters:
    Usage Type: Cost
    Data Type: Double
    Units Type: Meters
    Use by Default: False
    Source Attribute Evaluators:
      Streets (From-To): Field - [Meters]
      Streets (To-From): Field - [Meters]
    Default Attribute Evaluators:
      Default Edges: Constant - 0
      Default Junctions: Constant - 0
      Default Turns: Constant - 0

 

See the following code:

[VB.NET]

' Create a new EvaluatedNetworkAttribute object and populate its settings.
evalNetAttr = New EvaluatedNetworkAttribute
netAttr2 = CType(evalNetAttr, INetworkAttribute2)
With netAttr2
    .Name = "Meters"
    .UsageType = esriNAUTCost
    .DataType = esriNADTDouble
    .Units = esriNAUMeters
    .UseByDefault = False
End With

' Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
netFieldEval = New NetworkFieldEvaluator
netFieldEval.SetExpression("[Meters]", "")
evalNetAttr.Evaluator(edgeNetSource, esriNEDAlongDigitized) = netFieldEval
evalNetAttr.Evaluator(edgeNetSource, esriNEDAgainstDigitized) = netFieldEval

netConstEval = New NetworkConstantEvaluator
netConstEval.ConstantValue = 0
evalNetAttr.DefaultEvaluator(esriNETEdge) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETJunction) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETTurn) = netConstEval

' Add the attribute to the array.
attrArray.Add(evalNetAttr)

[C#]

// Create a new EvaluatedNetworkAttribute object and populate its settings.
IEvaluatedNetworkAttribute metersAttribute = new EvaluatedNetworkAttributeClass();
INetworkAttribute2 metersNetworkAttribute2 = (INetworkAttribute2)metersAttribute;
metersNetworkAttribute2.Name = "Meters";
metersNetworkAttribute2.UsageType = esriNetworkAttributeUsageType.esriNAUTCost;
metersNetworkAttribute2.DataType = esriNetworkAttributeDataType.esriNADTDouble;
metersNetworkAttribute2.Units = esriNetworkAttributeUnits.esriNAUMeters;
metersNetworkAttribute2.UseByDefault = false;

// Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
INetworkFieldEvaluator metersNetworkFieldEvaluator = new NetworkFieldEvaluatorClass()
    ;
INetworkEvaluator metersNetworkEvaluator = (INetworkEvaluator)
    metersNetworkFieldEvaluator;
metersNetworkFieldEvaluator.SetExpression("[Meters]", "");
metersAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAlongDigitized, metersNetworkEvaluator);
metersAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAgainstDigitized, metersNetworkEvaluator);

INetworkConstantEvaluator metersNetworkConstantEvaluator = new
    NetworkConstantEvaluatorClass();
INetworkEvaluator metersConstantNetworkEvaluator = (INetworkEvaluator)
    metersNetworkConstantEvaluator;
metersNetworkConstantEvaluator.ConstantValue = 0;
metersAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETEdge,
    metersConstantNetworkEvaluator);
metersAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETJunction,
    metersConstantNetworkEvaluator);
metersAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETTurn,
    metersConstantNetworkEvaluator);

// Add the attribute to the array.
attributeArray.Add(metersAttribute);

 

RoadClass network attribute

The following is from the New Network Dataset wizard's summary for the RoadClass network attribute:

 

RoadClass:
    Usage Type: Descriptor
    Data Type: Integer
    Units Type: Unknown
    Use by Default: False
    Source Attribute Evaluators:
      Streets (From-To): Field -
          Prelogic:
            rc = 1          'Local road
            Select Case UCase([CFCC])
              Case "A10", "A11", "A12", "A13", "A14", "A15", "A16", "A17", "A18", "A19"
                rc = 2          'Highway
              Case "A60", "A63"
                rc = 3          'Ramp
              Case "A65", "A66", "A68", "A69"
                rc = 4          'Ferry
              Case "A62"
                rc = 5          'Roundabout
            End Select
          Expression: rc
      Streets (To-From): Field -
          Prelogic:
            rc = 1          'Local road
            Select Case UCase([CFCC])
              Case "A10", "A11", "A12", "A13", "A14", "A15", "A16", "A17", "A18", "A19"
                rc = 2          'Highway
              Case "A60", "A63"
                rc = 3          'Ramp
              Case "A65", "A66", "A68", "A69"
                rc = 4          'Ferry
              Case "A62"
                rc = 5          'Roundabout
            End Select
          Expression: rc
    Default Attribute Evaluators:
      Default Edges: Constant - 0
      Default Junctions: Constant - 0
      Default Turns: Constant - 0

 

See the following code:

[VB.NET]

' Create a new EvaluatedNetworkAttribute object and populate its settings.
evalNetAttr = New EvaluatedNetworkAttribute
netAttr2 = CType(evalNetAttr, INetworkAttribute2)
With netAttr2
    .Name = "RoadClass"
    .UsageType = esriNAUTDescriptor
    .DataType = esriNADTInteger
    .Units = esriNAUUnknown
    .UseByDefault = False
End With

' Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
netFieldEval = New NetworkFieldEvaluator
netFieldEval.SetExpression("rc", _
                           "rc = 1          'Local road" & vbNewLine & _
                           "Select Case UCase([CFCC])" & vbNewLine & _
                           "  Case ""A10"", ""A11"", ""A12"", ""A13"", ""A14"", ""A15"", ""A16"", ""A17"", ""A18"", ""A19""" & vbNewLine & _
                           "    rc = 2          'Highway" & vbNewLine & _
                           "  Case ""A60"", ""A63""" & vbNewLine & _
                           "    rc = 3          'Ramp" & vbNewLine & _
                           "  Case ""A65"", ""A66"", ""A68"", ""A69""" & vbNewLine & _
                           "    rc = 4          'Ferry" & vbNewLine & _
                           "  Case ""A62""" & vbNewLine & _
                           "    rc = 5          'Roundabout" & vbNewLine & _
                           "End Select")
evalNetAttr.Evaluator(edgeNetSource, esriNEDAlongDigitized) = netFieldEval
evalNetAttr.Evaluator(edgeNetSource, esriNEDAgainstDigitized) = netFieldEval

netConstEval = New NetworkConstantEvaluator
netConstEval.ConstantValue = 0
evalNetAttr.DefaultEvaluator(esriNETEdge) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETJunction) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETTurn) = netConstEval

' Add the attribute to the array.
attrArray.Add(evalNetAttr)

[C#]

// Create a new EvaluatedNetworkAttribute object and populate its settings.
IEvaluatedNetworkAttribute roadClassAttribute = new EvaluatedNetworkAttributeClass();
INetworkAttribute2 roadClassNetworkAttribute2 = (INetworkAttribute2)
    roadClassAttribute;
roadClassNetworkAttribute2.Name = "RoadClass";
roadClassNetworkAttribute2.UsageType =
    esriNetworkAttributeUsageType.esriNAUTDescriptor;
roadClassNetworkAttribute2.DataType = esriNetworkAttributeDataType.esriNADTInteger;
roadClassNetworkAttribute2.Units = esriNetworkAttributeUnits.esriNAUUnknown;
roadClassNetworkAttribute2.UseByDefault = false;

// Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
INetworkFieldEvaluator roadClassNetworkFieldEvaluator = new
    NetworkFieldEvaluatorClass();
INetworkEvaluator roadClassNetworkEvaluator = (INetworkEvaluator)
    roadClassNetworkFieldEvaluator;
roadClassNetworkFieldEvaluator.SetExpression("rc", 
    "rc = 1 'Local road\n\rSelect Case UCase([CFCC])\n\r" + 
    " Case \"A10\", \"A11\", \"A12\", \"A13\", \"A14\", \"A15\", \"A16\", \"A17\", \"A18\", \"A19\"\n\r" + " rc = 2 'Highway\n\r" + " Case \"A60\", \"A63\"\n\r" + " rc = 3 'Ramp\n\r" + " Case \"A65\", \"A66\", \"A68\", \"A69\"\n\r" + " rc = 4 'Ferry\n\r" + " Case \"A62\"\n\r" + " rc = 5 'Roundabout\n\r" + "End Select");
roadClassAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAlongDigitized, roadClassNetworkEvaluator);
roadClassAttribute.set_Evaluator(edgeNetworkSource,
    esriNetworkEdgeDirection.esriNEDAgainstDigitized, roadClassNetworkEvaluator);

INetworkConstantEvaluator roadClassNetworkConstantEvaluator = new
    NetworkConstantEvaluatorClass();
INetworkEvaluator roadClassConstantNetworkEvaluator = (INetworkEvaluator)
    roadClassNetworkConstantEvaluator;
roadClassNetworkConstantEvaluator.ConstantValue = 0;
roadClassAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETEdge,
    roadClassConstantNetworkEvaluator);
roadClassAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETJunction,
    roadClassConstantNetworkEvaluator);
roadClassAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETTurn,
    roadClassConstantNetworkEvaluator);

// Add the attribute to the array.
attributeArray.Add(roadClassAttribute);

 

TurnRestriction network attribute

The following is from the New Network Dataset wizard's summary for the TurnRestriction network attribute:

 

TurnRestriction:
    Usage Type: Restriction
    Data Type: Boolean
    Units Type: Unknown
    Use by Default: True
    Source Attribute Evaluators:
      ParisTurns: Constant - Restricted
    Default Attribute Evaluators:
      Default Edges: Constant - Traversable
      Default Junctions: Constant - Traversable
      Default Turns: Constant - Traversable 

 

See the following code:

[VB.NET]

' Create a new EvaluatedNetworkAttribute object and populate its settings.
evalNetAttr = New EvaluatedNetworkAttribute
netAttr2 = CType(evalNetAttr, INetworkAttribute2)
With netAttr2
    .Name = "TurnRestriction"
    .UsageType = esriNAUTRestriction
    .DataType = esriNADTBoolean
    .Units = esriNAUUnknown
    .UseByDefault = True
End With

' Create evaluator objects and set them on the EvaluatedNetworkAttribute object.
netConstEval = New NetworkConstantEvaluator
netConstEval.ConstantValue = True 'True means Restricted.
evalNetAttr.Evaluator(turnNetSource, esriNEDNone) = netConstEval

netConstEval = New NetworkConstantEvaluator
netConstEval.ConstantValue = False 'False means Traversable (that is, not restricted).
evalNetAttr.DefaultEvaluator(esriNETEdge) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETJunction) = netConstEval
evalNetAttr.DefaultEvaluator(esriNETTurn) = netConstEval

' Add the attribute to the array.
attrArray.Add(evalNetAttr)

[C#]

// Create a new EvaluatedNetworkAttribute object and populate its settings.
IEvaluatedNetworkAttribute turnAttribute = new EvaluatedNetworkAttributeClass();
INetworkAttribute2 turnNetworkAttribute2 = (INetworkAttribute2)turnAttribute;
turnNetworkAttribute2.Name = "TurnRestriction";
turnNetworkAttribute2.UsageType = esriNetworkAttributeUsageType.esriNAUTDescriptor;
turnNetworkAttribute2.DataType = esriNetworkAttributeDataType.esriNADTInteger;
turnNetworkAttribute2.Units = esriNetworkAttributeUnits.esriNAUUnknown;
turnNetworkAttribute2.UseByDefault = false;

INetworkConstantEvaluator turnTrueNetworkConstantEvaluator = new
    NetworkConstantEvaluatorClass();
INetworkEvaluator turnTrueNetworkEvaluator = (INetworkEvaluator)
    turnTrueNetworkConstantEvaluator;
turnTrueNetworkConstantEvaluator.ConstantValue = true;
turnAttribute.set_Evaluator(turnNetworkSource, esriNetworkEdgeDirection.esriNEDNone,
    turnTrueNetworkEvaluator);

INetworkConstantEvaluator turnFalseNetworkConstantEvaluator = new
    NetworkConstantEvaluatorClass();
INetworkEvaluator turnFalseNetworkEvaluator = (INetworkEvaluator)
    turnFalseNetworkConstantEvaluator;
turnFalseNetworkConstantEvaluator.ConstantValue = false;
turnAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETEdge,
    turnFalseNetworkEvaluator);
turnAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETJunction,
    turnFalseNetworkEvaluator);
turnAttribute.set_DefaultEvaluator(esriNetworkElementType.esriNETTurn,
    turnFalseNetworkEvaluator);

// Add the attribute to the array.
attributeArray.Add(turnAttribute);

 

Now that all the attributes have been added to the array, the array to the network dataset data element can be added. See the following code:

 

[VB.NET]

deND.Attributes = attrArray

[C#]

deNetworkDataset.Attributes = attributeArray;

 

Specifying directions settings

The network dataset has settings for generating driving directions. The source-specific settings were specified when the EdgeFeatureSource was created. Next, the general settings will be specified.

 

General directions settings

The following is from the New Network Dataset wizard's summary for the General Directions settings:

 

  General Directions:
    Display Length Units: Miles
    Length Attribute: Meters
    Time Attribute: Minutes
    Road Class Attribute: RoadClass

 

These directions settings will be used when creating a new NetworkDirections object, then the object will be added to the network dataset data element object. See the following code:

 

[VB.NET]

' Create a NetworkDirections object and populate its settings.
Dim netDirections As INetworkDirections = New NetworkDirections
With netDirections
    .DefaultOutputLengthUnits = esriNAUMiles
    .LengthAttributeName = "Meters"
    .TimeAttributeName = "Minutes"
    .RoadClassAttributeName = "RoadClass"
End With

' Add the NetworkDirections object to the network dataset data element.
deND.Directions = netDirections

[C#]

// Create a NetworkDirections object and populate its settings.
INetworkDirections networkDirections = new NetworkDirectionsClass();
networkDirections.DefaultOutputLengthUnits = esriNetworkAttributeUnits.esriNAUMeters;
networkDirections.LengthAttributeName = "Meters";
networkDirections.TimeAttributeName = "Minutes";
networkDirections.RoadClassAttributeName = "RoadClass";

// Add the NetworkDirections object to the network dataset data element.
deNetworkDataset.Directions = networkDirections;

 

Creating and building the network dataset

All the network dataset settings are now included on the data element, and the network dataset can be created. A network dataset is created through the Network Dataset Feature Dataset extension. Once the network dataset is created, build it using the INetworkBuild interface. See the following code:

[VB.NET]

' Get the feature dataset extension and create the network dataset based on the data element.
Dim fdxc As IFeatureDatasetExtensionContainer = CType(fdsGDS, IFeatureDatasetExtensionContainer)
Dim fdx As IFeatureDatasetExtension = fdxc.FindExtension(esriDTNetworkDataset)
Dim dsc2 As IDatasetContainer2 = CType(fdx, IDatasetContainer2)
Dim netDataset As INetworkDataset = CType(dsc2.CreateDataset(deND), INetworkDataset)

' Once the network dataset is created, build it.
Dim netBuild As INetworkBuild = CType(netDataset, INetworkBuild)
netBuild.BuildNetwork(fdsGDS.Extent)

[C#]

// Get the feature dataset extension and create the network dataset based on the data element.
IFeatureDatasetExtensionContainer fdxContainer = (IFeatureDatasetExtensionContainer)
    featureDataset;
IFeatureDatasetExtension fdExtension = fdxContainer.FindExtension
    (esriDatasetType.esriDTNetworkDataset);
IDatasetContainer2 datasetContainer2 = (IDatasetContainer2)fdExtension;
IDEDataset deDataset = (IDEDataset)deNetworkDataset;
INetworkDataset networkDataset = (INetworkDataset)datasetContainer2.CreateDataset
    (deDataset);

// Once the network dataset is created, build it.
INetworkBuild networkBuild = (INetworkBuild)networkDataset;
networkBuild.BuildNetwork(geoDataset.Extent);