How to: Implement a Route Calculator Using GIS Providers

• Nov 13, 2018
• 6 minutes to read

This example demonstrates how to create a calculating routes application using GIS services.

Follow the steps below.

• Add an ImageTilesLayer object to the MapControl.Layers collection and assign an instance of the BingMapDataProvider class to the ImageLayer.DataProvider property. Specify the valid Bing key using the BingMapDataProvider.BingKey property.
• Add an InformationLayer object to the MapControl.Layers collection and assign an instance of the BingSearchDataProvider to the InformationLayer.DataProvider property. Set the LayerBase.Name property of the layer to SearchLayer.
• Add an InformationLayer object to the MapControl.Layers collection and assign an instance of the BingGeocodeDataProvider to the InformationLayer.DataProvider property. Set the LayerBase.Name property of the layer to GeocodeLayer.
• Add an InformationLayer object to the MapControl.Layers collection and assign an instance of the BingRouteDataProvider to the InformationLayer.DataProvider property. Set the LayerBase.Name property of the layer to RouteLayer.
• For each information layers’ data provider, specify the valid Bing key using the BingMapDataProviderBase.BingKey property and set the InformationDataProviderBase.GenerateLayerItems property value to false.

• Create a helper, which allows you to convert MapPushpin objects to RouteWaypoint and store the route using a MapPolyline object.

  Form1.cs

  class RoutingHelper {
      List<MapPushpin> pushpins = new List<MapPushpin>();
      MapPolyline route = new MapPolyline() {
          StrokeWidth = 4,
          SelectedStrokeWidth = 4,
          Stroke = Color.FromArgb(0xFF, 0xFE, 0x72, 0xFF)
      };
      List<RouteWaypoint> waypoints = new List<RouteWaypoint>();
      char currentLatter = 'A';
  
      public List<MapPushpin> Pushpins { get { return pushpins; } }
      public List<RouteWaypoint> Waypoints { get { return waypoints; } }
      public MapPolyline Route { get { return route; } set { route = value; } }
      public int Count { get { return pushpins.Count; } }
  
      public void BuildRoute(IEnumerable<GeoPoint> points) {
          route.Points.Clear();
          foreach (GeoPoint point in points)
              route.Points.Add(point);
      }
  
      public void AddItem(MapPushpin pushpin) {
          pushpins.Add(pushpin);
          waypoints.Add(new RouteWaypoint(
              ((LocationInformation)pushpin.Information).DisplayName,
              (GeoPoint)pushpin.Location)
          );
          pushpin.Text = (currentLatter++).ToString();
      }
  
      public void Clear() {
          route.Points.Clear();
          pushpins.Clear();
          waypoints.Clear();
          currentLatter = 'A';
      }
  }
  

  Form1.vb

  Friend Class RoutingHelper
  
      Private pushpins_Renamed As New List(Of MapPushpin)()
  
      Private route_Renamed As New MapPolyline() With {.StrokeWidth = 4, .SelectedStrokeWidth = 4, .Stroke = Color.FromArgb(&HFF, &HFE, &H72, &HFF)}
  
      Private waypoints_Renamed As New List(Of RouteWaypoint)()
      Private currentLatter As Char = "A"c
  
      Public ReadOnly Property Pushpins() As List(Of MapPushpin)
          Get
              Return pushpins_Renamed
          End Get
      End Property
      Public ReadOnly Property Waypoints() As List(Of RouteWaypoint)
          Get
              Return waypoints_Renamed
          End Get
      End Property
      Public Property Route() As MapPolyline
          Get
              Return route_Renamed
          End Get
          Set(ByVal value As MapPolyline)
              route_Renamed = value
          End Set
      End Property
      Public ReadOnly Property Count() As Integer
          Get
              Return pushpins_Renamed.Count
          End Get
      End Property
  
      Public Sub BuildRoute(ByVal points As IEnumerable(Of GeoPoint))
          route_Renamed.Points.Clear()
          For Each point As GeoPoint In points
              route_Renamed.Points.Add(point)
          Next point
      End Sub
  
      Public Sub AddItem(ByVal pushpin As MapPushpin)
          pushpins_Renamed.Add(pushpin)
          waypoints_Renamed.Add(New RouteWaypoint(CType(pushpin.Information, LocationInformation).DisplayName, CType(pushpin.Location, GeoPoint)))
          pushpin.Text = (currentLatter).ToString()
          currentLatter = ChrW(AscW(currentLatter) + 1)
      End Sub
  
      Public Sub Clear()
          route_Renamed.Points.Clear()
          pushpins_Renamed.Clear()
          waypoints_Renamed.Clear()
          currentLatter = "A"c
      End Sub
  End Class
  

• Prepare properties and members of the form class as follows.

  Form1.cs

  InformationLayer SearchLayer { get { return (InformationLayer)mapControl1.Layers["SearchLayer"]; } }
  BingSearchDataProvider SearchProvider { get { return (BingSearchDataProvider)SearchLayer.DataProvider; } }
  
  InformationLayer GeocodeLayer { get { return (InformationLayer)mapControl1.Layers["GeocodeLayer"]; } }
  BingGeocodeDataProvider GeocodeProvider { get { return (BingGeocodeDataProvider)GeocodeLayer.DataProvider; } }
  
  InformationLayer RouteLayer { get { return (InformationLayer)mapControl1.Layers["RouteLayer"]; } }
  BingRouteDataProvider RouteProvider { get { return (BingRouteDataProvider)RouteLayer.DataProvider; } }
  
  VectorItemsLayer ItemsLayer { get { return (VectorItemsLayer)mapControl1.Layers["ItemsLayer"]; } }
  MapItemStorage Storage { get { return (MapItemStorage)ItemsLayer.Data; } }
  
  RoutingHelper helper = new RoutingHelper();
  

  Form1.vb

  Private ReadOnly Property SearchLayer() As InformationLayer
      Get
          Return CType(mapControl1.Layers("SearchLayer"), InformationLayer)
      End Get
  End Property
  Private ReadOnly Property SearchProvider() As BingSearchDataProvider
      Get
          Return CType(SearchLayer.DataProvider, BingSearchDataProvider)
      End Get
  End Property
  
  Private ReadOnly Property GeocodeLayer() As InformationLayer
      Get
          Return CType(mapControl1.Layers("GeocodeLayer"), InformationLayer)
      End Get
  End Property
  Private ReadOnly Property GeocodeProvider() As BingGeocodeDataProvider
      Get
          Return CType(GeocodeLayer.DataProvider, BingGeocodeDataProvider)
      End Get
  End Property
  
  Private ReadOnly Property RouteLayer() As InformationLayer
      Get
          Return CType(mapControl1.Layers("RouteLayer"), InformationLayer)
      End Get
  End Property
  Private ReadOnly Property RouteProvider() As BingRouteDataProvider
      Get
          Return CType(RouteLayer.DataProvider, BingRouteDataProvider)
      End Get
  End Property
  
  Private ReadOnly Property ItemsLayer() As VectorItemsLayer
      Get
          Return CType(mapControl1.Layers("ItemsLayer"), VectorItemsLayer)
      End Get
  End Property
  Private ReadOnly Property Storage() As MapItemStorage
      Get
          Return CType(ItemsLayer.Data, MapItemStorage)
      End Get
  End Property
  
  Private helper As New RoutingHelper()
  

• Handle BingSearchDataProvider.SearchCompleted, BingGeocodeDataProvider.LocationInformationReceived and BingRouteDataProvider.RouteCalculated events.

  Form1.cs

      SearchProvider.SearchCompleted += SearchProvider_SearchCompleted;
      GeocodeProvider.LocationInformationReceived += GeocodeProvider_LocationInformationReceived;
      RouteProvider.RouteCalculated += RouteProvider_RouteCalculated;
  void GenerateItems(IEnumerable<LocationInformation> locations) {
      UpdateStorage();
      foreach (var location in locations) {
          MapPushpin pushpin = new MapPushpin() { Location = location.Location, Information = location };
          Storage.Items.Add(pushpin);
      }
  }
  
  void UpdateStorage() {
      Storage.Items.Clear();
      Storage.Items.Add(helper.Route);
      foreach (MapPushpin pushpin in helper.Pushpins)
          Storage.Items.Add(pushpin);
  }
  void SearchProvider_SearchCompleted(object sender, BingSearchCompletedEventArgs e) {
      if (e.Cancelled || (e.RequestResult.ResultCode != RequestResultCode.Success)) return;
  
      if (e.RequestResult.SearchResults.Count != 0)
          GenerateItems(e.RequestResult.SearchResults);
  }
  void GeocodeProvider_LocationInformationReceived(object sender, LocationInformationReceivedEventArgs e) {
      if (e.Cancelled) return;
  
      GenerateItems(e.Result.Locations);
  }
  void RouteProvider_RouteCalculated(object sender, BingRouteCalculatedEventArgs e) {
      if (e.Cancelled) return;
  
      if (e.CalculationResult.ResultCode == RequestResultCode.Success) {
          helper.BuildRoute(e.CalculationResult.RouteResults[0].RoutePath);
          UpdateStorage();
      }
  }
  

  Form1.vb

      AddHandler SearchProvider.SearchCompleted, AddressOf SearchProvider_SearchCompleted
      AddHandler GeocodeProvider.LocationInformationReceived, AddressOf GeocodeProvider_LocationInformationReceived
      AddHandler RouteProvider.RouteCalculated, AddressOf RouteProvider_RouteCalculated
  Private Sub GenerateItems(ByVal locations As IEnumerable(Of LocationInformation))
      UpdateStorage()
  
      For Each location_Renamed In locations
          Dim pushpin As New MapPushpin() With {.Location = location_Renamed.Location, .Information = location_Renamed}
          Storage.Items.Add(pushpin)
      Next location_Renamed
  End Sub
  
  Private Sub UpdateStorage()
      Storage.Items.Clear()
      Storage.Items.Add(helper.Route)
      For Each pushpin As MapPushpin In helper.Pushpins
          Storage.Items.Add(pushpin)
      Next pushpin
  End Sub
  Private Sub SearchProvider_SearchCompleted(ByVal sender As Object, ByVal e As BingSearchCompletedEventArgs)
      If e.Cancelled OrElse (e.RequestResult.ResultCode <> RequestResultCode.Success) Then
          Return
      End If
  
      If e.RequestResult.SearchResults.Count <> 0 Then
          GenerateItems(e.RequestResult.SearchResults)
      End If
  End Sub
  Private Sub GeocodeProvider_LocationInformationReceived(ByVal sender As Object, ByVal e As LocationInformationReceivedEventArgs)
      If e.Cancelled Then
          Return
      End If
  
      GenerateItems(e.Result.Locations)
  End Sub
  Private Sub RouteProvider_RouteCalculated(ByVal sender As Object, ByVal e As BingRouteCalculatedEventArgs)
      If e.Cancelled Then
          Return
      End If
  
      If e.CalculationResult.ResultCode = RequestResultCode.Success Then
          helper.BuildRoute(e.CalculationResult.RouteResults(0).RoutePath)
          UpdateStorage()
      End If
  End Sub
  

• Handle the MapControl.MapItemClick event to add data to the helper.

  Form1.cs

  void CalculateRoute() {
      if (helper.Count < 2) return;
      RouteProvider.CalculateRoute(helper.Waypoints);
  }
  private void mapControl1_MapItemClick(object sender, MapItemClickEventArgs e) {
      MapPushpin pushpin = e.Item as MapPushpin;
      if (pushpin == null) return;
      if (helper.Pushpins.Contains(pushpin)) return;
  
      helper.AddItem(pushpin);
      CalculateRoute();
      e.Handled = true;
  }
  

  Form1.vb

  Private Sub CalculateRoute()
      If helper.Count < 2 Then
          Return
      End If
      RouteProvider.CalculateRoute(helper.Waypoints)
  End Sub
  Private Sub mapControl1_MapItemClick(ByVal sender As Object, ByVal e As MapItemClickEventArgs) Handles mapControl1.MapItemClick
      Dim pushpin As MapPushpin = TryCast(e.Item, MapPushpin)
      If pushpin Is Nothing Then
          Return
      End If
      If helper.Pushpins.Contains(pushpin) Then
          Return
      End If
  
      helper.AddItem(pushpin)
      CalculateRoute()
      e.Handled = True
  End Sub