About the Vehicle routing problem solver Sample
[C#]
frmVRPSolver.cs
//*************************************************************************************
// ArcGIS Network Analyst extension - VRP Solver Demonstration
//
// This simple code shows how to:
// 1) Open a workspace and open a Network DataSet
// 2) Create a NAContext and its NASolver
// 3) Load Orders, Routes, Depots and Breaks from Feature Classes (or Table) and create Network Locations
// 4) Set the Solver parameters
// 5) Solve a VRP problem
// 6) Read the VRP output to display the Route and Break output information
//************************************************************************************
using System;
using System.Windows.Forms;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.NetworkAnalyst;
using System.Text;
namespace VRP_CSharp
{
public partial class frmVRPSolver : Form
{
private INAContext m_NAContext;
private System.Collections.Hashtable m_unitTimeList;
private System.Collections.Hashtable m_unitDistList;
private readonly string OUTPUTCLASSNAME = "Routes";
public frmVRPSolver()
{
InitializeComponent();
Initialize();
}
/// <summary>
/// Initialize the solver by calling the ArcGIS Network Analyst extension functions.
/// </summary>
private void Initialize()
{
IFeatureWorkspace featureWorkspace = null;
INetworkDataset networkDataset = null;
try
{
// Open Geodatabase and network dataset
IWorkspace workspace = OpenWorkspace(Application.StartupPath + @"\..\..\..\..\..\Data\SanFrancisco\SanFrancisco.gdb");
networkDataset = OpenNetworkDataset(workspace, "Transportation", "Streets_ND");
featureWorkspace = workspace as IFeatureWorkspace;
}
catch (Exception ex)
{
System.Windows.Forms.MessageBox.Show("Unable to open dataset. Error Message: " + ex.Message);
this.Close();
return;
}
// Create NAContext and NASolver
m_NAContext = CreateSolverContext(networkDataset);
// Get available cost attributes from the network dataset
INetworkAttribute networkAttribute;
for (int i = 0; i < networkDataset.AttributeCount; i++)
{
networkAttribute = networkDataset.get_Attribute(i);
if (networkAttribute.UsageType == esriNetworkAttributeUsageType.esriNAUTCost)
{
string unitType = GetAttributeUnitType(networkAttribute.Units);
if (unitType == "Time")
{
comboTimeAttribute.Items.Add(networkAttribute.Name);
}
else if (unitType == "Distance")
{
comboDistanceAttribute.Items.Add(networkAttribute.Name);
}
}
}
comboTimeAttribute.SelectedIndex = 0;
comboDistanceAttribute.SelectedIndex = 0;
// Populate time field unit in comboBox
m_unitTimeList = new System.Collections.Hashtable();
m_unitTimeList.Add("Seconds", esriNetworkAttributeUnits.esriNAUSeconds);
m_unitTimeList.Add("Minutes", esriNetworkAttributeUnits.esriNAUMinutes);
foreach (System.Collections.DictionaryEntry timeUnit in m_unitTimeList)
{
comboTimeUnits.Items.Add(timeUnit.Key.ToString());
}
comboTimeUnits.SelectedIndex = 1;
// Populate distance field unit in comboBox
m_unitDistList = new System.Collections.Hashtable();
m_unitDistList.Add("Miles", esriNetworkAttributeUnits.esriNAUMiles);
m_unitDistList.Add("Meters", esriNetworkAttributeUnits.esriNAUMeters);
foreach (System.Collections.DictionaryEntry distUnit in m_unitDistList)
{
comboDistUnits.Items.Add(distUnit.Key.ToString());
}
comboDistUnits.SelectedIndex = 0;
// Populate time window importance attribute in comboBox
comboTWImportance.Items.Add("High");
comboTWImportance.Items.Add("Medium");
comboTWImportance.Items.Add("Low");
comboTWImportance.SelectedIndex = 0;
// Load locations
IFeatureClass inputFClass = featureWorkspace.OpenFeatureClass("Stores");
LoadNANetworkLocations("Orders", inputFClass as ITable);
inputFClass = featureWorkspace.OpenFeatureClass("DistributionCenter");
LoadNANetworkLocations("Depots", inputFClass as ITable);
inputFClass = featureWorkspace.OpenFeatureClass("Routes");
LoadNANetworkLocations("Routes", inputFClass as ITable);
ITable inputTable = featureWorkspace.OpenTable("Breaks");
LoadNANetworkLocations("Breaks", inputTable);
// Create layer for network dataset and add to ArcMap
INetworkLayer networkLayer = new NetworkLayerClass();
networkLayer.NetworkDataset = networkDataset;
ILayer layer = networkLayer as ILayer;
layer.Name = "Network Dataset";
axMapControl.AddLayer(layer, 0);
// Create a network analysis layer and add to ArcMap
INALayer naLayer = m_NAContext.Solver.CreateLayer(m_NAContext);
layer = naLayer as ILayer;
layer.Name = m_NAContext.Solver.DisplayName;
axMapControl.AddLayer(layer, 0);
}
/// <summary>
/// Call VRP solver and display the results
/// </summary>
/// <param name="sender">Sender of the event</param>
/// <param name="e">Event</param>
private void cmdSolve_Click(object sender, EventArgs e)
{
this.Cursor = Cursors.WaitCursor;
listOutput.Items.Clear();
IGPMessages gpMessages = new GPMessagesClass();
try
{
listOutput.Items.Add("Solving...");
SetSolverSettings();
// Solve
m_NAContext.Solver.Solve(m_NAContext, gpMessages, null);
// Get the VRP output
DisplayOutput();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
listOutput.Items.Add(GetGPMessagesAsString(gpMessages));
cmdSolve.Text = "Find VRP Solution";
RefreshMapDisplay();
this.Cursor = Cursors.Default;
}
/// <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();
}
/// <summary>
/// Refresh the map display
/// <summary>
public void RefreshMapDisplay()
{
// Zoom to the extent of the service areas
IGeoDataset geoDataset = m_NAContext.NAClasses.get_ItemByName(OUTPUTCLASSNAME) as IGeoDataset;
IEnvelope envelope = geoDataset.Extent;
if (!envelope.IsEmpty)
{
envelope.Expand(1.1, 1.1, true);
axMapControl.Extent = envelope;
m_NAContext.Solver.UpdateLayer(axMapControl.get_Layer(0) as INALayer);
}
axMapControl.Refresh();
}
/// <summary>
/// Get the VRP route output
/// </summary>
public void DisplayOutput()
{
// Display route information
ITable naTable = m_NAContext.NAClasses.get_ItemByName(OUTPUTCLASSNAME) as ITable;
if (naTable.RowCount(null) > 0)
{
listOutput.Items.Add("Route Name,\tOrder Count,\tTotal Cost,\tTotal Time,\tTotal Distance,\tStart Time,\tEnd Time:");
string routeName;
long orderCount;
double totalCost;
double totalTime;
double totalDistance;
string routeStart;
string routeEnd;
ICursor naCursor = naTable.Search(null, false);
IRow naRow = naCursor.NextRow();
// Display route details
while (naRow != null)
{
routeName = naRow.get_Value(naTable.FindField("Name")).ToString();
orderCount = long.Parse(naRow.get_Value(naTable.FindField("OrderCount")).ToString());
totalCost = double.Parse(naRow.get_Value(naTable.FindField("TotalCost")).ToString());
totalTime = double.Parse(naRow.get_Value(naTable.FindField("TotalTime")).ToString());
totalDistance = double.Parse(naRow.get_Value(naTable.FindField("TotalDistance")).ToString());
routeStart = Convert.ToDateTime(naRow.get_Value(naTable.FindField("StartTime")).ToString()).ToString("T");
routeEnd = Convert.ToDateTime(naRow.get_Value(naTable.FindField("EndTime")).ToString()).ToString("T");
listOutput.Items.Add(routeName + ",\t\t" + orderCount.ToString() + ",\t\t" + totalCost.ToString("#0.00") + ",\t\t" + totalTime.ToString("#0.00")
+ ",\t\t" + totalDistance.ToString("#0.00") + ",\t\t" + routeStart + ",\t\t" + routeEnd);
naRow = naCursor.NextRow();
}
}
listOutput.Items.Add("");
// Display lunch break information
ITable naBreakTable = m_NAContext.NAClasses.get_ItemByName("Breaks") as ITable;
if (naBreakTable.RowCount(null) > 0)
{
listOutput.Items.Add("Route Name,\tBreak Start Time,\tBreak End Time:");
ICursor naCursor = naBreakTable.Search(null, false);
IRow naRow = naCursor.NextRow();
string routeName;
string startTime;
string endTime;
// Display lunch details for each route
while (naRow != null)
{
routeName = naRow.get_Value(naBreakTable.FindField("RouteName")).ToString();
startTime = Convert.ToDateTime(naRow.get_Value(naBreakTable.FindField("ArriveTime")).ToString()).ToString("T");
endTime = Convert.ToDateTime(naRow.get_Value(naBreakTable.FindField("DepartTime")).ToString()).ToString("T");
listOutput.Items.Add(routeName + ",\t\t" + startTime + ",\t\t" + endTime);
naRow = naCursor.NextRow();
}
}
listOutput.Refresh();
}
#region Geodatabase functions: open workspace and network dataset
/// <summary>
/// Geodatabase function: open workspace
/// </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">Dataset name</param>
/// <returns>Network dataset</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;
}
#endregion
#region Network analyst functions
/// <summary>
/// Create NASolver and NAContext
/// </summary>
/// <param name="networkDataset">Input network dataset</param>
/// <returns>NAContext</returns>
public INAContext CreateSolverContext(INetworkDataset networkDataset)
{
// Get the data element
IDENetworkDataset deNDS = GetDENetworkDataset(networkDataset);
INASolver naSolver = new NAVRPSolver();
INAContextEdit contextEdit = naSolver.CreateContext(deNDS, naSolver.Name) as INAContextEdit;
// Bind a context using the network dataset
contextEdit.Bind(networkDataset, new GPMessagesClass());
return contextEdit as INAContext;
}
/// <summary>
/// Load the input table and create field map to map fields from input table to NAClass
/// </summary>
/// <param name="strNAClassName">NAClass name</param>
/// <param name="inputTable">Input table</param>
public void LoadNANetworkLocations(string strNAClassName, ITable inputTable)
{
INamedSet classes = m_NAContext.NAClasses;
INAClass naClass = classes.get_ItemByName(strNAClassName) as INAClass;
// Delete existing rows from the specified NAClass
naClass.DeleteAllRows();
// Create a NAClassLoader and set the snap tolerance (meters unit)
INAClassLoader loader = new NAClassLoader();
loader.Locator = m_NAContext.Locator;
loader.Locator.SnapTolerance = 100;
loader.NAClass = naClass;
// Create field map to automatically map fields from input table to NAclass
INAClassFieldMap fieldMap = new NAClassFieldMapClass();
fieldMap.CreateMapping(naClass.ClassDefinition, inputTable.Fields);
loader.FieldMap = fieldMap;
// 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 input table
int rowsIn = 0;
int rowsLocated = 0;
loader.Load(inputTable.Search(null, true), null, ref rowsIn, ref rowsLocated);
// Message all of the network analysis agents that the analysis context has changed.
INAContextEdit naContextEdit = m_NAContext as INAContextEdit;
naContextEdit.ContextChanged();
}
/// <summary>
/// Set solver settings
/// </summary>
public void SetSolverSettings()
{
// Set VRP solver specific settings
INASolver solver = m_NAContext.Solver;
INAVRPSolver vrpSolver = solver as INAVRPSolver;
// Both orders and routes have capacity count of 2 in the input shape files. User can modify the input data and update this value accordingly.
vrpSolver.CapacityCount = 2;
// Read the time and distance unit from comboBox
vrpSolver.DistanceFieldUnits = (esriNetworkAttributeUnits)m_unitDistList[comboDistUnits.Items[comboDistUnits.SelectedIndex].ToString()];
vrpSolver.TimeFieldUnits = (esriNetworkAttributeUnits)m_unitTimeList[comboTimeUnits.Items[comboTimeUnits.SelectedIndex].ToString()];
// The value of time window violation penalty factor can be adjusted in terms of the user's preference.
string importance = comboTWImportance.Items[comboTWImportance.SelectedIndex].ToString();
if (importance == "Low")
vrpSolver.TimeWindowViolationPenaltyFactor = 0;
else if (importance == "Medium")
vrpSolver.TimeWindowViolationPenaltyFactor = 1;
else if (importance == "High")
vrpSolver.TimeWindowViolationPenaltyFactor = 10;
// Set output line type
vrpSolver.OutputLines = esriNAOutputLineType.esriNAOutputLineStraight;
// Set generic solver settings
// Set the impedance attribute
INASolverSettings solverSettings = solver as INASolverSettings;
solverSettings.ImpedanceAttributeName = comboTimeAttribute.Text;
// Set the accumulated attribute
IStringArray accumulatedAttributes = solverSettings.AccumulateAttributeNames;
accumulatedAttributes.RemoveAll();
accumulatedAttributes.Insert(0, comboDistanceAttribute.Text);
solverSettings.AccumulateAttributeNames = accumulatedAttributes;
// Set the oneway restriction if necessary
IStringArray restrictions = solverSettings.RestrictionAttributeNames;
restrictions.RemoveAll();
if (checkUseRestriction.Checked)
restrictions.Add("oneway");
solverSettings.RestrictionAttributeNames = restrictions;
// Restrict UTurns
solverSettings.RestrictUTurns = esriNetworkForwardStarBacktrack.esriNFSBNoBacktrack;
// Set the hierarchy attribute
solverSettings.UseHierarchy = checkUseHierarchy.Checked;
if (solverSettings.UseHierarchy)
solverSettings.HierarchyAttributeName = "HierarchyMultiNet";
// Do not forget to update the context after you set your impedance
solver.UpdateContext(m_NAContext, GetDENetworkDataset(m_NAContext.NetworkDataset), new GPMessagesClass());
}
#endregion
/// <summary>
/// Check whether the attribute unit is time or distance unit.
/// </summary>
/// <param name="units">Input network attribute units</param>
/// <returns>Unit type</returns>
private string GetAttributeUnitType(esriNetworkAttributeUnits units)
{
string unitType = "";
switch (units)
{
case esriNetworkAttributeUnits.esriNAUDays:
case esriNetworkAttributeUnits.esriNAUHours:
case esriNetworkAttributeUnits.esriNAUMinutes:
case esriNetworkAttributeUnits.esriNAUSeconds:
unitType = "Time";
break;
case esriNetworkAttributeUnits.esriNAUYards:
case esriNetworkAttributeUnits.esriNAUMillimeters:
case esriNetworkAttributeUnits.esriNAUMiles:
case esriNetworkAttributeUnits.esriNAUMeters:
case esriNetworkAttributeUnits.esriNAUKilometers:
case esriNetworkAttributeUnits.esriNAUInches:
case esriNetworkAttributeUnits.esriNAUFeet:
case esriNetworkAttributeUnits.esriNAUDecimeters:
case esriNetworkAttributeUnits.esriNAUNauticalMiles:
case esriNetworkAttributeUnits.esriNAUCentimeters:
unitType = "Distance";
break;
default:
listOutput.Items.Add("Failed to find Network Attribute Units.");
break;
}
return unitType;
}
}
}
[Visual Basic .NET]
frmVRPSolver.vb
'*************************************************************************************
' ArcGIS Network Analyst extension - VRP Solver Demonstration
'
' This simple code shows how to:
' 1) Open a workspace and open a Network DataSet
' 2) Create a NAContext and its NASolver
' 3) Load Orders, Routes, Depots and Breaks from Feature Classes (or Table) and create Network Locations
' 4) Set the Solver parameters
' 5) Solve a VRP problem
' 6) Read the VRP output to display the Route and Break output information
'************************************************************************************
Imports Microsoft.VisualBasic
Imports System
Imports System.Windows.Forms
Imports ESRI.ArcGIS.Geodatabase
Imports ESRI.ArcGIS.NetworkAnalyst
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.Geometry
Partial Public Class frmVRPSolver
Inherits Form
Private m_NAContext As INAContext
Private m_unitTimeList As System.Collections.Hashtable
Private m_unitDistList As System.Collections.Hashtable
Public Sub New()
'This call is required by the Windows Form Designer.
InitializeComponent()
'Add any initialization after the InitializeComponent() call
Initialize()
End Sub
''' <summary>
''' Initialize the solver by calling the ArcGIS Network Analyst extension functions.
''' </summary>
Private Sub Initialize()
Dim featureWorkspace As IFeatureWorkspace = Nothing
Dim networkDataset As INetworkDataset = Nothing
' Open network dataset
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
System.Windows.Forms.MessageBox.Show("Unable to open dataset. Error Message: " & ex.Message)
Me.Close()
Return
End Try
' Create NAContext and NASolver
m_NAContext = CreateSolverContext(networkDataset)
' Get available cost attributes from the network dataset
Dim networkAttribute As INetworkAttribute
For i As Integer = 0 To networkDataset.AttributeCount - 1
networkAttribute = networkDataset.Attribute(i)
If networkAttribute.UsageType = esriNetworkAttributeUsageType.esriNAUTCost Then
Dim unitType As String = GetAttributeUnitType(networkAttribute.Units)
If unitType = "Time" Then
comboTimeAttribute.Items.Add(networkAttribute.Name)
ElseIf unitType = "Distance" Then
comboDistanceAttribute.Items.Add(networkAttribute.Name)
End If
End If
Next i
comboTimeAttribute.SelectedIndex = 0
comboDistanceAttribute.SelectedIndex = 0
' Populate time field unit in comboBox
m_unitTimeList = New System.Collections.Hashtable()
m_unitTimeList.Add("Seconds", esriNetworkAttributeUnits.esriNAUSeconds)
m_unitTimeList.Add("Minutes", esriNetworkAttributeUnits.esriNAUMinutes)
For Each timeUnit As System.Collections.DictionaryEntry In m_unitTimeList
comboTimeUnits.Items.Add(timeUnit.Key.ToString())
Next timeUnit
comboTimeUnits.SelectedIndex = 1
' Populate distance field unit in comboBox
m_unitDistList = New System.Collections.Hashtable()
m_unitDistList.Add("Miles", esriNetworkAttributeUnits.esriNAUMiles)
m_unitDistList.Add("Meters", esriNetworkAttributeUnits.esriNAUMeters)
For Each distUnit As System.Collections.DictionaryEntry In m_unitDistList
comboDistUnits.Items.Add(distUnit.Key.ToString())
Next distUnit
comboDistUnits.SelectedIndex = 0
' Populate time window importance attribute in comboBox
comboTWImportance.Items.Add("High")
comboTWImportance.Items.Add("Medium")
comboTWImportance.Items.Add("Low")
comboTWImportance.SelectedIndex = 0
' Load locations
Dim inputFClass As IFeatureClass = featureWorkspace.OpenFeatureClass("Stores")
LoadNANetworkLocations("Orders", TryCast(inputFClass, ITable))
inputFClass = featureWorkspace.OpenFeatureClass("DistributionCenter")
LoadNANetworkLocations("Depots", TryCast(inputFClass, ITable))
inputFClass = featureWorkspace.OpenFeatureClass("Routes")
LoadNANetworkLocations("Routes", TryCast(inputFClass, ITable))
Dim inputTable As ITable = featureWorkspace.OpenTable("Breaks")
LoadNANetworkLocations("Breaks", inputTable)
' Create layer for network dataset and add to ArcMap
Dim networkLayer As INetworkLayer = New NetworkLayerClass()
networkLayer.NetworkDataset = networkDataset
Dim layer As ILayer = TryCast(networkLayer, ILayer)
layer.Name = "Network Dataset"
AxMapControl.AddLayer(layer, 0)
' Create a network analysis layer and add to ArcMap
Dim naLayer As INALayer = m_NAContext.Solver.CreateLayer(m_NAContext)
layer = TryCast(naLayer, ILayer)
layer.Name = m_NAContext.Solver.DisplayName
AxMapControl.AddLayer(layer, 0)
End Sub
''' <summary>
''' Call VRP solver and display the results
''' </summary>
''' <param name="sender">Sender of the event</param>
''' <param name="e">Event</param>
Private Sub cmdSolve_Click(ByVal sender As Object, ByVal e As EventArgs) Handles cmdSolve.Click
Dim gpMessages As IGPMessages = New GPMessagesClass()
Try
listOutput.Items.Clear()
cmdSolve.Text = "Solving..."
SetSolverSettings()
' Solve
m_NAContext.Solver.Solve(m_NAContext, gpMessages, Nothing)
' Get the VRP output
DisplayOutput()
' Zoom to the extent of the routes
Dim gDataset As IGeoDataset = TryCast(m_NAContext.NAClasses.ItemByName("Routes"), IGeoDataset)
Dim envelope As IEnvelope = gDataset.Extent
If (Not envelope.IsEmpty) Then
envelope.Expand(1.1, 1.1, True)
axMapControl.Extent = envelope
End If
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
cmdSolve.Text = "Find VRP Solution"
End Try
listOutput.Items.Add(GetGPMessagesAsString(GPMessages))
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
''' <summary>
''' Get the VRP route output
''' </summary>
Public Sub DisplayOutput()
' Display route information
Dim naTable As ITable = TryCast(m_NAContext.NAClasses.ItemByName("Routes"), ITable)
If naTable.RowCount(Nothing) > 0 Then
listOutput.Items.Add("Route Name," & Constants.vbTab & "Order Count," & Constants.vbTab & "Total Cost," & Constants.vbTab & "Total Time," & Constants.vbTab & "Total Distance," & Constants.vbTab & "Start Time," & Constants.vbTab & "End Time:")
Dim routeName As String
Dim orderCount As Long
Dim totalCost As Double
Dim totalTime As Double
Dim totalDistance As Double
Dim routeStart As String
Dim routeEnd As String
Dim naCursor As ICursor = naTable.Search(Nothing, False)
Dim naRow As IRow = naCursor.NextRow()
' Display route details
Do While Not naRow Is Nothing
routeName = naRow.Value(naTable.FindField("Name")).ToString()
orderCount = Long.Parse(naRow.Value(naTable.FindField("OrderCount")).ToString())
totalCost = Double.Parse(naRow.Value(naTable.FindField("TotalCost")).ToString())
totalTime = Double.Parse(naRow.Value(naTable.FindField("TotalTime")).ToString())
totalDistance = Double.Parse(naRow.Value(naTable.FindField("TotalDistance")).ToString())
routeStart = Convert.ToDateTime(naRow.Value(naTable.FindField("StartTime")).ToString()).ToString("T")
routeEnd = Convert.ToDateTime(naRow.Value(naTable.FindField("EndTime")).ToString()).ToString("T")
listOutput.Items.Add(routeName & "," & Constants.vbTab + Constants.vbTab + orderCount.ToString() & "," & Constants.vbTab + Constants.vbTab + totalCost.ToString("#0.00") & "," & Constants.vbTab + Constants.vbTab + totalTime.ToString("#0.00") & "," & Constants.vbTab + Constants.vbTab + totalDistance.ToString("#0.00") & "," & Constants.vbTab + Constants.vbTab & routeStart & "," & Constants.vbTab + Constants.vbTab & routeEnd)
naRow = naCursor.NextRow()
Loop
End If
listOutput.Items.Add("")
' Display lunch break information
Dim naBreakTable As ITable = TryCast(m_NAContext.NAClasses.ItemByName("Breaks"), ITable)
If naBreakTable.RowCount(Nothing) > 0 Then
listOutput.Items.Add("Route Name," & Constants.vbTab & "Break Start Time," & Constants.vbTab & "Break End Time:")
Dim naCursor As ICursor = naBreakTable.Search(Nothing, False)
Dim naRow As IRow = naCursor.NextRow()
Dim routeName As String
Dim startTime As String
Dim endTime As String
' Display lunch details for each route
Do While Not naRow Is Nothing
routeName = naRow.Value(naBreakTable.FindField("RouteName")).ToString()
startTime = Convert.ToDateTime(naRow.Value(naBreakTable.FindField("ArriveTime")).ToString()).ToString("T")
endTime = Convert.ToDateTime(naRow.Value(naBreakTable.FindField("DepartTime")).ToString()).ToString("T")
listOutput.Items.Add(routeName & "," & Constants.vbTab + Constants.vbTab & startTime & "," & Constants.vbTab + Constants.vbTab & endTime)
naRow = naCursor.NextRow()
Loop
End If
listOutput.Refresh()
End Sub
#Region "Network analyst functions"
''' <summary>
''' Create NASolver and NAContext
''' </summary>
''' <param name="networkDataset">Input network dataset</param>
''' <returns>NAContext</returns>
Public Function CreateSolverContext(ByVal networkDataset As INetworkDataset) As INAContext
' Get the data element
Dim deNDS As IDENetworkDataset = GetDENetworkDataset(networkDataset)
Dim naSolver As INASolver = New NAVRPSolver()
Dim contextEdit As INAContextEdit = TryCast(naSolver.CreateContext(deNDS, naSolver.Name), INAContextEdit)
' Bind a context using the network dataset
contextEdit.Bind(networkDataset, New GPMessagesClass())
Return TryCast(contextEdit, INAContext)
End Function
''' <summary>
''' Load the input table and create field map to map fields from input table to NAClass
''' </summary>
''' <param name="strNAClassName">NAClass name</param>
''' <param name="inputTable">Input table</param>
Public Sub LoadNANetworkLocations(ByVal strNAClassName As String, ByVal inputTable As ITable)
Dim classes As INamedSet = m_NAContext.NAClasses
Dim naClass As INAClass = TryCast(classes.ItemByName(strNAClassName), INAClass)
' Delete existing rows from the specified NAClass
naClass.DeleteAllRows()
' Create a NAClassLoader and set the snap tolerance (meters unit)
Dim loader As INAClassLoader = New NAClassLoader()
loader.Locator = m_NAContext.Locator
loader.Locator.SnapTolerance = 100
loader.NAClass = naClass
' Create field map to automatically map fields from input table to NAclass
Dim fieldMap As INAClassFieldMap = New NAClassFieldMapClass()
fieldMap.CreateMapping(naClass.ClassDefinition, inputTable.Fields)
loader.FieldMap = fieldMap
' 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 input table
Dim rowsIn As Integer = 0
Dim rowsLocated As Integer = 0
loader.Load(inputTable.Search(Nothing, True), Nothing, rowsIn, rowsLocated)
' Message all of the network analysis agents that the analysis context has changed.
Dim naContextEdit As INAContextEdit = TryCast(m_NAContext, INAContextEdit)
naContextEdit.ContextChanged()
End Sub
''' <summary>
''' Set solver settings
''' </summary>
Public Sub SetSolverSettings()
' Set VRP solver specific settings
Dim solver As INASolver = m_NAContext.Solver
Dim vrpSolver As INAVRPSolver = TryCast(solver, INAVRPSolver)
' Both orders and routes have capacity count of 2 in the input shape files. User can modify the input data and update this value accordingly.
vrpSolver.CapacityCount = 2
' Read the time and distance unit from comboBox
vrpSolver.DistanceFieldUnits = CType(m_unitDistList(comboDistUnits.Items(comboDistUnits.SelectedIndex).ToString()), esriNetworkAttributeUnits)
vrpSolver.TimeFieldUnits = CType(m_unitTimeList(comboTimeUnits.Items(comboTimeUnits.SelectedIndex).ToString()), esriNetworkAttributeUnits)
' The value of time window violation penalty factor can be adjusted in terms of the user's preference.
Dim importance As String = comboTWImportance.Items(comboTWImportance.SelectedIndex).ToString()
If importance = "Low" Then
vrpSolver.TimeWindowViolationPenaltyFactor = 0
ElseIf importance = "Medium" Then
vrpSolver.TimeWindowViolationPenaltyFactor = 1
ElseIf importance = "High" Then
vrpSolver.TimeWindowViolationPenaltyFactor = 10
End If
' Set output line type
vrpSolver.OutputLines = esriNAOutputLineType.esriNAOutputLineStraight
' Set generic solver settings
' Set the impedance attribute
Dim solverSettings As INASolverSettings = TryCast(solver, INASolverSettings)
solverSettings.ImpedanceAttributeName = comboTimeAttribute.Text
' Set the accumulated attribute
Dim accumulatedAttributes As IStringArray = solverSettings.AccumulateAttributeNames
accumulatedAttributes.RemoveAll()
accumulatedAttributes.Insert(0, comboDistanceAttribute.Text)
solverSettings.AccumulateAttributeNames = accumulatedAttributes
' Set the oneway restriction if necessary
Dim restrictions As IStringArray = solverSettings.RestrictionAttributeNames
restrictions.RemoveAll()
If checkUseRestriction.Checked Then
restrictions.Add("oneway")
End If
solverSettings.RestrictionAttributeNames = restrictions
' Restrict UTurns
solverSettings.RestrictUTurns = esriNetworkForwardStarBacktrack.esriNFSBNoBacktrack
' Set the hierarchy attribute
solverSettings.UseHierarchy = checkUseHierarchy.Checked
If solverSettings.UseHierarchy Then
solverSettings.HierarchyAttributeName = "HierarchyMultiNet"
End If
' Do not forget to update the context after you set your impedance
solver.UpdateContext(m_NAContext, GetDENetworkDataset(m_NAContext.NetworkDataset), New GPMessagesClass())
End Sub
#End Region
#Region "Geodatabase functions: open workspace and network dataset"
''' <summary>
''' Geodatabase function: open workspace
''' </summary>
''' <param name="strGDBName">File name</param>
''' <returns>Workspace</returns>
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
''' <summary>
''' Geodatabase function: open network dataset
''' </summary>
''' <param name="workspace">Work space</param>
''' <param name="strNDSName">Dataset name</param>
''' <returns>Network dataset</returns>
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
''' <summary>
''' Geodatabase function: get network dataset
''' </summary>
''' <param name="networkDataset">Input network dataset</param>
''' <returns>DE network dataset</returns>
Public Function GetDENetworkDataset(ByVal networkDataset As INetworkDataset) As IDENetworkDataset
' Cast from the network dataset to the DatasetComponent
Dim dsComponent As IDatasetComponent = TryCast(networkDataset, IDatasetComponent)
' Get the data element
Return TryCast(dsComponent.DataElement, IDENetworkDataset)
End Function
#End Region
''' <summary>
''' Check whether the attribute unit is time or distance unit.
''' </summary>
''' <param name="units">Input network attribute units</param>
''' <returns>Unit type</returns>
Private Function GetAttributeUnitType(ByVal units As esriNetworkAttributeUnits) As String
Dim unitType As String = ""
Select Case units
Case esriNetworkAttributeUnits.esriNAUDays, esriNetworkAttributeUnits.esriNAUHours, esriNetworkAttributeUnits.esriNAUMinutes, esriNetworkAttributeUnits.esriNAUSeconds
unitType = "Time"
Case esriNetworkAttributeUnits.esriNAUYards, esriNetworkAttributeUnits.esriNAUMillimeters, esriNetworkAttributeUnits.esriNAUMiles, esriNetworkAttributeUnits.esriNAUMeters, esriNetworkAttributeUnits.esriNAUKilometers, esriNetworkAttributeUnits.esriNAUInches, esriNetworkAttributeUnits.esriNAUFeet, esriNetworkAttributeUnits.esriNAUDecimeters, esriNetworkAttributeUnits.esriNAUNauticalMiles, esriNetworkAttributeUnits.esriNAUCentimeters
unitType = "Distance"
Case Else
listOutput.Items.Add("Failed to find Network Attribute Units.")
End Select
Return unitType
End Function
End Class