About the Service area solver Sample
[C#]
frmServiceAreaSolver.cs
using System;
using System.Windows.Forms;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.NetworkAnalyst;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geometry;
using System.Text;
namespace ServiceAreaSolver
{
public partial class frmServiceAreaSolver : Form
{
private INAContext m_NAContext;
#region Main Form Constructor and Setup
/// <summary>
/// Initialize the solver by calling the ArcGIS Network Analyst extension functions.
/// </summary>
public frmServiceAreaSolver()
{
InitializeComponent();
Initialize();
}
/// <summary>
/// Set up the default values on the form
/// </summary>
private void Initialize()
{
txtCutOff.Text = "5";
lstOutput.Items.Clear();
cbCostAttribute.Items.Clear();
ckbUseRestriction.Checked = false;
axMapControl.ClearLayers();
txtWorkspacePath.Text = Application.StartupPath + @"\..\..\..\..\..\Data\SanFrancisco\SanFrancisco.gdb";
txtNetworkDataset.Text = "Streets_ND";
txtFeatureDataset.Text = "Transportation";
txtInputFacilities.Text = "Hospitals";
gbServiceAreaSolver.Enabled = false;
}
#endregion
#region Button Clicks
/// <summary>
/// Call the Service Area solver and display the results
/// </summary>
/// <param name="sender">Sender of the event</param>
/// <param name="e">Event</param>
private void btnSolve_Click(object sender, EventArgs e)
{
this.Cursor = Cursors.WaitCursor;
lstOutput.Items.Clear();
IGPMessages gpMessages = new GPMessagesClass();
try
{
lstOutput.Items.Clear();
lstOutput.Items.Add("Solving...");
ConfigureSolverSettings();
if (m_NAContext.Solver.Solve(m_NAContext, gpMessages, null))
lstOutput.Items.Add("Partial Solve Generated.");
DisplayOutput();
}
catch (Exception ee)
{
lstOutput.Items.Add("Failure: " + ee.Message);
}
lstOutput.Items.Add(GetGPMessagesAsString(gpMessages));
RefreshMapDisplay();
this.Cursor = Cursors.Default;
}
/// <summary>
/// Open the network dataset and set up the map
/// </summary>
/// <param name="sender">Sender of the event</param>
/// <param name="e">Event</param>
private void btnLoadMap_Click(object sender, EventArgs e)
{
this.Cursor = Cursors.WaitCursor;
gbServiceAreaSolver.Enabled = false;
lstOutput.Items.Clear();
// Verify that the workspace is valid
IWorkspace workspace = OpenWorkspace(txtWorkspacePath.Text);
if (workspace != null)
{
// Open the network dataset and generate a solver/context
INetworkDataset networkDataset = OpenNetworkDataset(workspace, txtFeatureDataset.Text, txtNetworkDataset.Text);
IFeatureWorkspace featureWorkspace = workspace as IFeatureWorkspace;
CreateSolverContext(networkDataset);
if (m_NAContext != null)
{
LoadCostAttributes(networkDataset);
if (LoadLocations(featureWorkspace))
{
AddNetworkDatasetLayerToMap(networkDataset);
AddNetworkAnalysisLayerToMap();
// work around a transparency issue
IGeoDataset geoDataset = networkDataset as IGeoDataset;
axMapControl.Extent = axMapControl.FullExtent;
axMapControl.Extent = geoDataset.Extent;
if (m_NAContext != null) gbServiceAreaSolver.Enabled = true;
}
}
}
this.Cursor = Cursors.Default;
}
#endregion
#region Set up Context and Solver
/// <summary>
/// Geodatabase function: open work space
/// </summary>
/// <param name="strGDBName">Input file name</param>
/// <returns>Workspace</returns>
public IWorkspace OpenWorkspace(string strGDBName)
{
// As Workspace Factories are Singleton objects, they must be instantiated with the Activator
var workspaceFactory = System.Activator.CreateInstance(System.Type.GetTypeFromProgID("esriDataSourcesGDB.FileGDBWorkspaceFactory")) as ESRI.ArcGIS.Geodatabase.IWorkspaceFactory;
if (!System.IO.Directory.Exists(strGDBName))
{
MessageBox.Show("The workspace: " + strGDBName + " does not exist", "Workspace Error");
return null;
}
IWorkspace workspace = null;
try
{
workspace = workspaceFactory.OpenFromFile(strGDBName, 0);
}
catch (Exception ex)
{
MessageBox.Show("Opening workspace failed: " + ex.Message, "Workspace Error");
}
return workspace;
}
/// <summary>
/// Geodatabase function: open network dataset
/// </summary>
/// <param name="workspace">Input workspace</param>
/// <param name="strNDSName">Input network dataset name</param>
/// <returns>NetworkDataset</returns>
public INetworkDataset OpenNetworkDataset(IWorkspace workspace, string featureDatasetName, string strNDSName)
{
// Obtain the dataset container from the workspace
var featureWorkspace = workspace as IFeatureWorkspace;
ESRI.ArcGIS.Geodatabase.IFeatureDataset featureDataset = featureWorkspace.OpenFeatureDataset(featureDatasetName);
var featureDatasetExtensionContainer = featureDataset as ESRI.ArcGIS.Geodatabase.IFeatureDatasetExtensionContainer;
ESRI.ArcGIS.Geodatabase.IFeatureDatasetExtension featureDatasetExtension = featureDatasetExtensionContainer.FindExtension(ESRI.ArcGIS.Geodatabase.esriDatasetType.esriDTNetworkDataset);
var datasetContainer3 = featureDatasetExtension as ESRI.ArcGIS.Geodatabase.IDatasetContainer3;
// Use the container to open the network dataset.
ESRI.ArcGIS.Geodatabase.IDataset dataset = datasetContainer3.get_DatasetByName(ESRI.ArcGIS.Geodatabase.esriDatasetType.esriDTNetworkDataset, strNDSName);
return dataset as ESRI.ArcGIS.Geodatabase.INetworkDataset;
}
/// <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 element
return 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());
}
#endregion
#region Load Form Controls
/// <summary>
/// Find and load the cost attributes into a combo box
/// <summary>
private void LoadCostAttributes(INetworkDataset networkDataset)
{
cbCostAttribute.Items.Clear();
int attrCount = networkDataset.AttributeCount;
for (int attrIndex = 0; attrIndex < attrCount; attrIndex++)
{
INetworkAttribute networkAttribute = networkDataset.get_Attribute(attrIndex);
if (networkAttribute.UsageType == esriNetworkAttributeUsageType.esriNAUTCost)
cbCostAttribute.Items.Add(networkAttribute.Name);
}
if (cbCostAttribute.Items.Count > 0)
cbCostAttribute.SelectedIndex = 0;
}
/// <summary>
/// Find and load the cost attributes into a combo box
/// <summary>
/// <param name="featureWorkspace">The workspace that holds the input feature class</param>
/// <returns>Success</returns>
private bool LoadLocations(IFeatureWorkspace featureWorkspace)
{
IFeatureClass inputFeatureClass = null;
try
{
inputFeatureClass = featureWorkspace.OpenFeatureClass(txtInputFacilities.Text);
}
catch (Exception)
{
MessageBox.Show("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 locations
int rowsIn = 0;
int rowsLocated = 0;
naClassLoader.Load(inputFeatureClass.Search(null, true) as ICursor, null, ref rowsIn, ref rowsLocated);
if (rowsLocated <= 0)
{
MessageBox.Show("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;
}
/// <summary>
/// Create a layer from the context and add it to the map
/// </summary>
private void AddNetworkAnalysisLayerToMap()
{
ILayer layer = m_NAContext.Solver.CreateLayer(m_NAContext) as ILayer;
layer.Name = m_NAContext.Solver.DisplayName;
axMapControl.AddLayer(layer);
}
/// <summary>
/// Create a layer for the network dataset and add it to the map
/// </summary>
private void AddNetworkDatasetLayerToMap(INetworkDataset networkDataset)
{
INetworkLayer networkLayer = new NetworkLayerClass();
networkLayer.NetworkDataset = networkDataset;
ILayer layer = networkLayer as ILayer;
layer.Name = "Network Dataset";
axMapControl.AddLayer(layer);
}
#endregion
#region Solver Settings
/// <summary>
/// Prepare the solver
/// </summary>
private void ConfigureSolverSettings()
{
ConfigureSettingsSpecificToServiceAreaSolver();
ConfigureGenericSolverSettings();
UpdateContextAfterChangingSettings();
}
/// <summary>
/// Update settings that only apply to the Service Area
/// </summary>
private void ConfigureSettingsSpecificToServiceAreaSolver()
{
INAServiceAreaSolver naSASolver = m_NAContext.Solver as INAServiceAreaSolver;
naSASolver.DefaultBreaks = ParseBreaks(txtCutOff.Text);
naSASolver.MergeSimilarPolygonRanges = false;
naSASolver.OutputPolygons = esriNAOutputPolygonType.esriNAOutputPolygonSimplified;
naSASolver.OverlapLines = true;
naSASolver.SplitLinesAtBreaks = false;
naSASolver.TravelDirection = esriNATravelDirection.esriNATravelDirectionFromFacility;
naSASolver.OutputLines = esriNAOutputLineType.esriNAOutputLineNone;
}
/// <summary>
/// Update settings that apply to all solvers
/// </summary>
private void ConfigureGenericSolverSettings()
{
INASolverSettings naSolverSettings = m_NAContext.Solver as INASolverSettings;
naSolverSettings.ImpedanceAttributeName = cbCostAttribute.Text;
// set the oneway restriction, if necessary
IStringArray restrictions = naSolverSettings.RestrictionAttributeNames;
restrictions.RemoveAll();
if (ckbUseRestriction.Checked)
restrictions.Add("Oneway");
naSolverSettings.RestrictionAttributeNames = restrictions;
//naSolverSettings.RestrictUTurns = esriNetworkForwardStarBacktrack.esriNFSBNoBacktrack;
}
/// <summary>
/// When the solver has been update, the context must be updated as well
/// </summary>
private void UpdateContextAfterChangingSettings()
{
IDatasetComponent datasetComponent = m_NAContext.NetworkDataset as IDatasetComponent;
IDENetworkDataset deNetworkDataset = datasetComponent.DataElement as IDENetworkDataset;
m_NAContext.Solver.UpdateContext(m_NAContext, deNetworkDataset, new GPMessagesClass());
}
/// <summary>
/// Prepare the text string for breaks
/// </summary>
private IDoubleArray ParseBreaks(string p)
{
String[] breaks = p.Split(' ');
IDoubleArray pBrks = new DoubleArrayClass();
int firstIndex = breaks.GetLowerBound(0);
int lastIndex = breaks.GetUpperBound(0);
for (int splitIndex = firstIndex; splitIndex <= lastIndex; splitIndex++)
{
try
{
pBrks.Add(Convert.ToDouble(breaks[splitIndex]));
}
catch (FormatException)
{
MessageBox.Show("Breaks are not properly formatted. Use only digits separated by spaces");
pBrks.RemoveAll();
return pBrks;
}
}
return pBrks;
}
#endregion
#region Post-Solve
/// <summary>
/// Display analysis results in the list box
/// </summary>
private void DisplayOutput()
{
ITable table = m_NAContext.NAClasses.get_ItemByName("SAPolygons") as ITable;
if (table.RowCount(null) > 0)
{
IGPMessage gpMessage = new GPMessageClass();
lstOutput.Items.Add("FacilityID, FromBreak, ToBreak");
ICursor cursor = table.Search(null, true);
IRow row = cursor.NextRow();
while (row != null)
{
int facilityID = (int)row.get_Value(table.FindField("FacilityID"));
double fromBreak = (double)row.get_Value(table.FindField("FromBreak"));
double toBreak = (double)row.get_Value(table.FindField("ToBreak"));
lstOutput.Items.Add(facilityID.ToString() + ", " + fromBreak.ToString("#####0.00") + ", " + toBreak.ToString("#####0.00"));
row = cursor.NextRow();
}
}
}
/// <summary>
/// Refresh the map display
/// <summary>
public void RefreshMapDisplay()
{
IGeoDataset geoDataset = m_NAContext.NAClasses.get_ItemByName("SAPolygons") as IGeoDataset;
IEnvelope envelope = geoDataset.Extent;
if (!envelope.IsEmpty)
{
envelope.Expand(1.1, 1.1, true);
axMapControl.Extent = envelope;
// Call this to update the renderer for the service area polygons
// based on the new breaks.
m_NAContext.Solver.UpdateLayer(axMapControl.get_Layer(0) as INALayer);
}
axMapControl.Refresh();
}
/// <summary>
/// Gather the error/warning/informative messages from GPMessages
/// <summary>
/// <param name="gpMessages">GPMessages container</param>
/// <returns>string of all GPMessages</returns>
public string GetGPMessagesAsString(IGPMessages gpMessages)
{
// Gather Error/Warning/Informative Messages
var messages = new StringBuilder();
if (gpMessages != null)
{
for (int i = 0; i < gpMessages.Count; i++)
{
IGPMessage gpMessage = gpMessages.GetMessage(i);
string message = gpMessage.Description;
switch (gpMessages.GetMessage(i).Type)
{
case esriGPMessageType.esriGPMessageTypeError:
messages.AppendLine("Error " + gpMessage.ErrorCode + ": " + message);
break;
case esriGPMessageType.esriGPMessageTypeWarning:
messages.AppendLine("Warning: " + message);
break;
default:
messages.AppendLine("Information: " + message);
break;
}
}
}
return messages.ToString();
}
#endregion
}
}
[Visual Basic .NET]
frmServiceAreaSolver.vb
Imports Microsoft.VisualBasic
Imports System
Imports System.Windows.Forms
Imports ESRI.ArcGIS.Geodatabase
Imports ESRI.ArcGIS.NetworkAnalyst
Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Geometry
Namespace ServiceAreaSolver
Partial Public Class frmServiceAreaSolver
Inherits Form
Private m_naContext As INAContext
#Region "Main Form Constructor and Setup"
Public Sub New()
InitializeComponent()
txtCutOff.Text = "5"
lbOutput.Items.Clear()
cbCostAttribute.Items.Clear()
ckbUseRestriction.Checked = False
axMapControl.ClearLayers()
txtWorkspacePath.Text = Application.StartupPath & "\..\..\..\..\..\Data\SanFrancisco\SanFrancisco.gdb"
txtNetworkDataset.Text = "Streets_ND"
txtFeatureDataset.Text = "Transportation"
txtInputFacilities.Text = "Hospitals"
gbServiceAreaSolver.Enabled = False
End Sub
#End Region
#Region "Button Clicks"
Private Sub btnSolve_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSolve.Click
Me.Cursor = Cursors.WaitCursor
lbOutput.Items.Clear()
Dim gpMessages As IGPMessages = New GPMessagesClass()
Try
ConfigureSolverSettings()
If (Not m_naContext.Solver.Solve(m_naContext, gpMessages, Nothing)) Then
lbOutput.Items.Add("Partial Result")
End If
DisplayOutput()
Catch ex As Exception
lbOutput.Items.Add("Solve Failed: " & ex.Message)
End Try
lbOutput.Items.Add(GetGPMessagesAsString(GPMessages))
UpdateMapDisplayAfterSolve()
Me.Cursor = Cursors.Default
End Sub
'*********************************************************************************
' Gather the error/warning/informative messages from GPMessages
'*********************************************************************************
Public Function GetGPMessagesAsString(ByVal gpMessages As IGPMessages) As String
Dim messages As System.Text.StringBuilder = New System.Text.StringBuilder()
If Not gpMessages Is Nothing Then
Dim i As Integer
For i = 0 To gpMessages.Count - 1
Dim gpMessage As IGPMessage = gpMessages.GetMessage(i)
Dim message As String = gpMessage.Description
Select Case gpMessage.Type
Case esriGPMessageType.esriGPMessageTypeError
messages.AppendLine("Error " + gpMessage.ErrorCode.ToString + ": " + message)
Case esriGPMessageType.esriGPMessageTypeWarning
messages.AppendLine("Warning: " + message)
Case Else
messages.AppendLine("Information: " + message)
End Select
Next
End If
Return messages.ToString()
End Function
Private Sub btnLoadMap_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnLoadMap.Click
Me.Cursor = Cursors.WaitCursor
gbServiceAreaSolver.Enabled = False
lbOutput.Items.Clear()
' Open geodatabase and network dataset
Dim featureWorkspace As IFeatureWorkspace = Nothing
Dim networkDataset As INetworkDataset = Nothing
Try
Dim workspace As IWorkspace = OpenWorkspace(Application.StartupPath & "\..\..\..\..\..\Data\SanFrancisco\SanFrancisco.gdb")
networkDataset = OpenNetworkDataset(workspace, "Transportation", "Streets_ND")
featureWorkspace = TryCast(workspace, IFeatureWorkspace)
Catch ex As Exception
Windows.Forms.MessageBox.Show("Unable to open dataset. Error Message: " + ex.Message)
Me.Cursor = Cursors.Default
Return
End Try
CreateContextAndSolver(networkDataset)
If m_naContext Is Nothing Then
Me.Cursor = Cursors.Default
Return
End If
LoadCostAttributes(networkDataset)
If (Not LoadLocations(featureWorkspace)) Then
Me.Cursor = Cursors.Default
Return
End If
AddNetworkDatasetLayerToMap(networkDataset)
AddNetworkAnalysisLayerToMap()
' work around a transparency issue
Dim geoDataset As IGeoDataset = TryCast(networkDataset, IGeoDataset)
axMapControl.Extent = axMapControl.FullExtent
axMapControl.Extent = geoDataset.Extent
If m_naContext IsNot Nothing Then
gbServiceAreaSolver.Enabled = True
End If
Me.Cursor = Cursors.Default
End Sub
#End Region
#Region "Set up Context and Solver"
'*********************************************************************************
' Geodatabase functions
'*********************************************************************************
Public Function OpenWorkspace(ByVal strGDBName As String) As IWorkspace
' As Workspace Factories are Singleton objects, they must be instantiated with the Activator
Dim workspaceFactory As IWorkspaceFactory = TryCast(Activator.CreateInstance(Type.GetTypeFromProgID("esriDataSourcesGDB.FileGDBWorkspaceFactory")), IWorkspaceFactory)
Return workspaceFactory.OpenFromFile(strGDBName, 0)
End Function
'*********************************************************************************
' Open the network dataset
'*********************************************************************************
Public Function OpenNetworkDataset(ByVal workspace As IWorkspace, ByVal featureDatasetName As String, ByVal strNDSName As String) As INetworkDataset
' Obtain the dataset container from the workspace
Dim featureWorkspace As IFeatureWorkspace = TryCast(workspace, IFeatureWorkspace)
Dim featureDataset As IFeatureDataset = featureWorkspace.OpenFeatureDataset(featureDatasetName)
Dim featureDatasetExtensionContainer As IFeatureDatasetExtensionContainer = TryCast(featureDataset, IFeatureDatasetExtensionContainer)
Dim featureDatasetExtension As IFeatureDatasetExtension = featureDatasetExtensionContainer.FindExtension(ESRI.ArcGIS.Geodatabase.esriDatasetType.esriDTNetworkDataset)
Dim datasetContainer3 As IDatasetContainer3 = TryCast(featureDatasetExtension, IDatasetContainer3)
' Use the container to open the network dataset
Dim dataset As Object = datasetContainer3.DatasetByName(ESRI.ArcGIS.Geodatabase.esriDatasetType.esriDTNetworkDataset, strNDSName)
Return TryCast(dataset, INetworkDataset)
End Function
Private Sub CreateContextAndSolver(ByVal networkDataset As INetworkDataset)
If networkDataset Is Nothing Then
Return
End If
Dim datasetComponent As IDatasetComponent = TryCast(networkDataset, IDatasetComponent)
Dim deNetworkDataset As IDENetworkDataset = TryCast(datasetComponent.DataElement, IDENetworkDataset)
Dim naSolver As INASolver = New NAServiceAreaSolverClass()
m_naContext = naSolver.CreateContext(deNetworkDataset, "ServiceArea")
Dim naContextEdit As INAContextEdit = TryCast(m_naContext, INAContextEdit)
naContextEdit.Bind(networkDataset, New GPMessagesClass())
End Sub
#End Region
#Region "Load Form Controls"
Private Sub LoadCostAttributes(ByVal networkDataset As INetworkDataset)
cbCostAttribute.Items.Clear()
Dim attrCount As Integer = networkDataset.AttributeCount
For attrIndex As Integer = 0 To attrCount - 1
Dim networkAttribute As INetworkAttribute = networkDataset.Attribute(attrIndex)
If networkAttribute.UsageType = esriNetworkAttributeUsageType.esriNAUTCost Then
cbCostAttribute.Items.Add(networkAttribute.Name)
End If
Next attrIndex
If cbCostAttribute.Items.Count > 0 Then
cbCostAttribute.SelectedIndex = 0
End If
End Sub
Private Function LoadLocations(ByVal featureWorkspace As IFeatureWorkspace) As Boolean
Dim inputFeatureClass As IFeatureClass = Nothing
Try
inputFeatureClass = featureWorkspace.OpenFeatureClass(txtInputFacilities.Text)
Catch e1 As Exception
MessageBox.Show("Specified input feature class does not exist")
Return False
End Try
Dim classes As INamedSet = m_naContext.NAClasses
Dim naClass As INAClass = TryCast(classes.ItemByName("Facilities"), INAClass)
' delete existing locations, except barriers
naClass.DeleteAllRows()
' Create a NAClassLoader and set the snap tolerance (meters unit)
Dim naClassLoader As INAClassLoader = New NAClassLoaderClass()
naClassLoader.Locator = m_naContext.Locator
naClassLoader.Locator.SnapTolerance = 100
naClassLoader.NAClass = naClass
' Create field map to automatically map fields from input class to NAClass
Dim naClassFieldMap As INAClassFieldMap = New NAClassFieldMapClass()
naClassFieldMap.CreateMapping(naClass.ClassDefinition, inputFeatureClass.Fields)
naClassLoader.FieldMap = naClassFieldMap
' Avoid loading network locations onto non-traversable portions of elements
Dim locator As INALocator3 = TryCast(m_naContext.Locator, INALocator3)
locator.ExcludeRestrictedElements = True
locator.CacheRestrictedElements(m_naContext)
' load network locations
Dim rowsIn As Integer = 0
Dim rowsLocated As Integer = 0
naClassLoader.Load(TryCast(inputFeatureClass.Search(Nothing, True), ICursor), Nothing, rowsIn, rowsLocated)
If rowsLocated <= 0 Then
MessageBox.Show("Facilities were not loaded from input feature class")
Return False
End If
' Message all of the network analysis agents that the analysis context has changed
Dim naContextEdit As INAContextEdit = TryCast(m_naContext, INAContextEdit)
naContextEdit.ContextChanged()
Return True
End Function
Private Sub AddNetworkAnalysisLayerToMap()
Dim layer As ILayer = TryCast(m_naContext.Solver.CreateLayer(m_naContext), ILayer)
layer.Name = m_naContext.Solver.DisplayName
axMapControl.AddLayer(layer)
End Sub
Private Sub AddNetworkDatasetLayerToMap(ByVal networkDataset As INetworkDataset)
Dim networkLayer As INetworkLayer = New NetworkLayerClass()
networkLayer.NetworkDataset = networkDataset
Dim layer As ILayer = TryCast(networkLayer, ILayer)
layer.Name = "Network Dataset"
axMapControl.AddLayer(layer)
End Sub
#End Region
#Region "Solver Settings"
Private Sub ConfigureSolverSettings()
ConfigureSettingsSpecificToServiceAreaSolver()
ConfigureGenericSolverSettings()
UpdateContextAfterChangingSettings()
End Sub
Private Sub ConfigureSettingsSpecificToServiceAreaSolver()
Dim naSASolver As INAServiceAreaSolver = TryCast(m_naContext.Solver, INAServiceAreaSolver)
naSASolver.DefaultBreaks = ParseBreaks(txtCutOff.Text)
naSASolver.MergeSimilarPolygonRanges = False
naSASolver.OutputPolygons = esriNAOutputPolygonType.esriNAOutputPolygonSimplified
naSASolver.OverlapLines = True
naSASolver.SplitLinesAtBreaks = False
naSASolver.TravelDirection = esriNATravelDirection.esriNATravelDirectionFromFacility
naSASolver.OutputLines = esriNAOutputLineType.esriNAOutputLineNone
End Sub
Private Sub ConfigureGenericSolverSettings()
Dim naSolverSettings As INASolverSettings = TryCast(m_naContext.Solver, INASolverSettings)
naSolverSettings.ImpedanceAttributeName = cbCostAttribute.Text
' set the oneway restriction, if necessary
Dim restrictions As IStringArray = naSolverSettings.RestrictionAttributeNames
restrictions.RemoveAll()
If ckbUseRestriction.Checked Then
restrictions.Add("oneway")
End If
naSolverSettings.RestrictionAttributeNames = restrictions
naSolverSettings.RestrictUTurns = esriNetworkForwardStarBacktrack.esriNFSBNoBacktrack
End Sub
Private Sub UpdateContextAfterChangingSettings()
Dim datasetComponent As IDatasetComponent = TryCast(m_naContext.NetworkDataset, IDatasetComponent)
Dim deNetworkDataset As IDENetworkDataset = TryCast(datasetComponent.DataElement, IDENetworkDataset)
m_naContext.Solver.UpdateContext(m_naContext, deNetworkDataset, New GPMessagesClass())
End Sub
Private Function ParseBreaks(ByVal p As String) As IDoubleArray
Dim breaks() As String = p.Split(" "c)
Dim pBrks As IDoubleArray = New DoubleArrayClass()
Dim firstIndex As Integer = breaks.GetLowerBound(0)
Dim lastIndex As Integer = breaks.GetUpperBound(0)
For splitIndex As Integer = firstIndex To lastIndex
Try
pBrks.Add(Convert.ToDouble(breaks(splitIndex)))
Catch e1 As FormatException
MessageBox.Show("Breaks are not properly formatted. Use only digits separated by spaces")
pBrks.RemoveAll()
Return pBrks
End Try
Next splitIndex
Return pBrks
End Function
#End Region
#Region "Post-Solve"
Private Sub LoadListboxAfterPartialSolve(ByVal gpMessages As IGPMessages)
lbOutput.Items.Add("Partial Solve Generated.")
For msgIndex As Integer = 0 To gpMessages.Messages.Count - 1
Dim errorText As String = ""
Select Case gpMessages.GetMessage(msgIndex).Type
Case esriGPMessageType.esriGPMessageTypeError
errorText = "Error " & gpMessages.GetMessage(msgIndex).ErrorCode.ToString() & " " & gpMessages.GetMessage(msgIndex).Description
Case esriGPMessageType.esriGPMessageTypeWarning
errorText = "Warning " & gpMessages.GetMessage(msgIndex).ErrorCode.ToString() & " " & gpMessages.GetMessage(msgIndex).Description
Case Else
errorText = "Information " & gpMessages.GetMessage(msgIndex).Description
End Select
lbOutput.Items.Add(errorText)
Next msgIndex
End Sub
Private Sub DisplayOutput()
Dim table As ITable = TryCast(m_naContext.NAClasses.ItemByName("SAPolygons"), ITable)
If table.RowCount(Nothing) > 0 Then
Dim gpMessage As IGPMessage = New GPMessageClass()
lbOutput.Items.Add("FacilityID, FromBreak, ToBreak")
Dim cursor As ICursor = table.Search(Nothing, True)
Dim row As IRow = cursor.NextRow()
Do While row IsNot Nothing
Dim facilityID As Integer = CInt(Fix(row.Value(table.FindField("FacilityID"))))
Dim fromBreak As Double = CDbl(row.Value(table.FindField("FromBreak")))
Dim toBreak As Double = CDbl(row.Value(table.FindField("ToBreak")))
lbOutput.Items.Add(facilityID.ToString() & ", " & fromBreak.ToString("#####0.00") & ", " & toBreak.ToString("#####0.00"))
row = cursor.NextRow()
Loop
End If
End Sub
Private Sub UpdateMapDisplayAfterSolve()
' Zoom to the extent of the service areas
Dim geoDataset As IGeoDataset = TryCast(m_naContext.NAClasses.ItemByName("SAPolygons"), IGeoDataset)
Dim envelope As IEnvelope = geoDataset.Extent
If (Not envelope.IsEmpty) Then
envelope.Expand(1.1, 1.1, True)
axMapControl.Extent = envelope
' Call this to update the renderer for the service area polygons
' based on the new breaks.
m_naContext.Solver.UpdateLayer(TryCast(axMapControl.get_Layer(0), INALayer))
End If
axMapControl.Refresh()
End Sub
#End Region
End Class
End Namespace