private async Task FindServiceAreas()
{
try
{
// Create the service area task.
_serviceAreaTask = await ServiceAreaTask.CreateAsync(new Uri(NetworkAnalysisUrl));
// Create the default parameters for the service.
ServiceAreaParameters serviceAreaParameters = await _serviceAreaTask.CreateDefaultParametersAsync();
// Configure the service area parameters.
serviceAreaParameters.PolygonDetail = ServiceAreaPolygonDetail.High;
serviceAreaParameters.ReturnPolygons = true;
serviceAreaParameters.DefaultImpedanceCutoffs.Clear();
serviceAreaParameters.DefaultImpedanceCutoffs.Add(0);
serviceAreaParameters.DefaultImpedanceCutoffs.Add(3);
serviceAreaParameters.DefaultImpedanceCutoffs.Add(5);
// A query that finds all of the relevant facilities from the facilities feature service.
QueryParameters facilityQueryParameters = new QueryParameters();
facilityQueryParameters.WhereClause = "1=1";
// Provide the feature service and the query as parameters to the service area task.
serviceAreaParameters.SetFacilities(_facilitiesTable, facilityQueryParameters);
// Perform the service area analysis.
ServiceAreaResult result = await _serviceAreaTask.SolveServiceAreaAsync(serviceAreaParameters);
// Count the features in the facilities layer.
long facilityCount = await _facilitiesTable.QueryFeatureCountAsync(facilityQueryParameters);
// Get the service area for each facility.
for (int facilityIndex = 0; facilityIndex < facilityCount; facilityIndex++)
{
// Get each area polygon from the result for that facility.
List <ServiceAreaPolygon> areaPolygons = result.GetResultPolygons(facilityIndex).ToList();
// Add each service area polygon to the graphics overlay.
for (int polygonIndex = 0; polygonIndex < areaPolygons.Count; polygonIndex++)
{
// Get the polygon from the result.
Polygon resultingPolygon = areaPolygons[polygonIndex].Geometry;
// Choose a symbol for the polygon.
SimpleFillSymbol selectedSymbol = _fillSymbols[polygonIndex % _fillSymbols.Count];
// Create and add the graphic.
_resultOverlay.Graphics.Add(new Graphic(resultingPolygon, selectedSymbol));
}
}
// Zoom to the extent of the results.
await _myMapView.SetViewpointGeometryAsync(_resultOverlay.Extent, 50);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex);
ShowMessage("Error", "Couldn't complete service area analysis.");
}
}
private async void ShowServiceAreasButtonClick(object sender, EventArgs e)
{
// Finish any drawings in progress.
if (_myMapView.SketchEditor.CompleteCommand.CanExecute(null))
{
_myMapView.SketchEditor.CompleteCommand.Execute(null);
}
// Update the UI.
_barrierButton.Text = "Draw barrier";
// Use a local variable for the graphics overlay.
GraphicCollection allGraphics = _myMapView.GraphicsOverlays[0].Graphics;
// Get a list of the facilities from the graphics overlay.
List <ServiceAreaFacility> serviceAreaFacilities = (from g in allGraphics
where (string)g.Attributes["Type"] == "Facility"
select new ServiceAreaFacility((MapPoint)g.Geometry)).ToList();
// Check that there is at least 1 facility to find a service area for.
if (!serviceAreaFacilities.Any())
{
CreateErrorDialog("Must have at least one Facility!");
return;
}
// Create the service area task and parameters based on the Uri.
ServiceAreaTask serviceAreaTask = await ServiceAreaTask.CreateAsync(_serviceAreaUri);
// Store the default parameters for the service area in an object.
ServiceAreaParameters serviceAreaParameters = await serviceAreaTask.CreateDefaultParametersAsync();
// Add impedance cutoffs for facilities (drive time minutes).
serviceAreaParameters.DefaultImpedanceCutoffs.Add(2.0);
serviceAreaParameters.DefaultImpedanceCutoffs.Add(5.0);
// Set the level of detail for the polygons.
serviceAreaParameters.PolygonDetail = ServiceAreaPolygonDetail.High;
// Get a list of the barriers from the graphics overlay.
List <PolylineBarrier> polylineBarriers = (from g in allGraphics
where (string)g.Attributes["Type"] == "Barrier"
select new PolylineBarrier((Polyline)g.Geometry)).ToList();
// Add the barriers to the service area parameters.
serviceAreaParameters.SetPolylineBarriers(polylineBarriers);
// Update the parameters to include all of the placed facilities.
serviceAreaParameters.SetFacilities(serviceAreaFacilities);
// Clear existing graphics for service areas.
foreach (Graphic g in allGraphics.ToList())
{
// Check if the graphic g is a service area.
if ((string)g.Attributes["Type"] == "ServiceArea")
{
allGraphics.Remove(g);
}
}
try
{
// Solve for the service area of the facilities.
ServiceAreaResult result = await serviceAreaTask.SolveServiceAreaAsync(serviceAreaParameters);
// Loop over each facility.
for (int i = 0; i < serviceAreaFacilities.Count; i++)
{
// Create list of polygons from a service facility.
List <ServiceAreaPolygon> polygons = result.GetResultPolygons(i).ToList();
// Symbol for the outline of the service areas.
SimpleLineSymbol serviceOutline = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, System.Drawing.Color.DarkGray, 3.0f);
// Create a list of fill symbols for the polygons.
List <SimpleFillSymbol> fillSymbols = new List <SimpleFillSymbol>();
fillSymbols.Add(new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, System.Drawing.Color.FromArgb(70, 255, 0, 0), serviceOutline));
fillSymbols.Add(new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, System.Drawing.Color.FromArgb(70, 255, 165, 0), serviceOutline));
// Loop over every polygon in every facilities result.
for (int j = 0; j < polygons.Count; j++)
{
// Create the graphic for the service areas, alternating between fill symbols.
Graphic serviceGraphic = new Graphic(polygons[j].Geometry, new Dictionary <string, object>()
{
{ "Type", "ServiceArea" }
}, fillSymbols[j % 2])
{
ZIndex = 0
};
// Add graphic for service area. Alternate the color of each polygon.
allGraphics.Add(serviceGraphic);
}
}
}
catch (Esri.ArcGISRuntime.Http.ArcGISWebException exception)
{
if (exception.Message.ToString().Equals("Unable to complete operation."))
{
CreateErrorDialog("Facility not within San Diego area!");
}
else
{
CreateErrorDialog("An ArcGIS web exception occurred. \n" + exception.Message);
}
}
}