private void MyMapView_GeoViewTapped(object sender, GeoViewInputEventArgs geoViewInputEventArgs)
{
// Get the tapped location.
MapPoint tappedLocation = geoViewInputEventArgs.Location;
// Show the tapped location.
_tappedLocationGraphic.Geometry = tappedLocation;
// Get the nearest vertex in the polygon.
ProximityResult nearestVertexResult = GeometryEngine.NearestVertex(_polygonGraphic.Geometry, tappedLocation);
// Get the nearest coordinate in the polygon.
ProximityResult nearestCoordinateResult =
GeometryEngine.NearestCoordinate(_polygonGraphic.Geometry, tappedLocation);
// Get the distance to the nearest vertex in the polygon.
int distanceVertex = (int)(nearestVertexResult.Distance / 1000);
// Get the distance to the nearest coordinate in the polygon.
int distanceCoordinate = (int)(nearestCoordinateResult.Distance / 1000);
// Show the nearest vertex in blue.
_nearestVertexGraphic.Geometry = nearestVertexResult.Coordinate;
// Show the nearest coordinate in red.
_nearestCoordinateGraphic.Geometry = nearestCoordinateResult.Coordinate;
// Show the distances in the UI.
_distanceLabel.Text = $"Vertex dist: {distanceVertex} km, Point dist: {distanceCoordinate} km";
}
private void MapViewTapped(object sender, Esri.ArcGISRuntime.Xamarin.Forms.GeoViewInputEventArgs geoViewInputEventArgs)
{
// Get the tapped location
MapPoint tappedLocation = geoViewInputEventArgs.Location;
// Show the tapped location
_tappedLocationGraphic.Geometry = tappedLocation;
// Get the nearest vertex in the polygon
ProximityResult nearestVertexResult = GeometryEngine.NearestVertex(_polygonGraphic.Geometry, tappedLocation);
// Get the nearest coordinate in the polygon
ProximityResult nearestCoordinateResult =
GeometryEngine.NearestCoordinate(_polygonGraphic.Geometry, tappedLocation);
// Get the distance to the nearest vertex in the polygon
int distanceVertex = (int)(nearestVertexResult.Distance / 1000);
// Get the distance to the nearest coordinate in the polygon
int distanceCoordinate = (int)(nearestCoordinateResult.Distance / 1000);
// Show the nearest vertex in blue
_nearestVertexGraphic.Geometry = nearestVertexResult.Coordinate;
// Show the nearest coordinate in red
_nearestCoordinateGraphic.Geometry = nearestCoordinateResult.Coordinate;
// Show the distances in the UI
ResultsLabel.Text = $"Vertex dist: {distanceVertex} km, Point dist: {distanceCoordinate} km";
}
// Accept user click point and find nearest target geometry point
private async Task GetNearestCoordAsync(bool vertexOnly)
{
var target = _targetOverlay.Graphics.Select(g => g.Geometry).FirstOrDefault();
if (target == null)
{
return;
}
txtInstruct.Text = "Click the map to find the nearest coordinate";
var point = await MyMapView.Editor.RequestPointAsync();
ProximityResult result = null;
if (vertexOnly)
{
result = GeometryEngine.NearestVertex(target, point);
}
else
{
result = GeometryEngine.NearestCoordinate(target, point);
}
_coordinateOverlay.Graphics.Clear();
_coordinateOverlay.Graphics.Add(new Graphic(point, _userPointSymbol));
_coordinateOverlay.Graphics.Add(new Graphic(result.Point));
txtResult.Visibility = Visibility.Visible;
txtResult.Text = string.Format("Nearest Point: Index: {0}, Distance: {1:0.000}", result.PointIndex, result.Distance);
}
private async Task UpdateGeometry(MapPoint point)
{
if (_selectedFeature.Geometry is Polyline line)
{
// Get the nearest point on the selected line.
ProximityResult nearestVertex = GeometryEngine.NearestVertex(line, point);
// Create a new polyline.
PolylineBuilder polylineBuilder = new PolylineBuilder(line);
Part part = polylineBuilder.Parts[nearestVertex.PartIndex];
// Replace the nearest point with the new point.
part.SetPoint(nearestVertex.PointIndex, point);
// Update the geometry of the feature.
_selectedFeature.Geometry = GeometryEngine.Project(polylineBuilder.ToGeometry(), _selectedFeature.Geometry.SpatialReference);
await _selectedFeature.FeatureTable.UpdateFeatureAsync(_selectedFeature);
}
else if (_selectedFeature.Geometry is MapPoint)
{
// Update the geometry of the feature.
_selectedFeature.Geometry = point;
await _selectedFeature.FeatureTable.UpdateFeatureAsync(_selectedFeature);
}
// Clear the selection.
(_selectedFeature.FeatureTable.Layer as FeatureLayer).ClearSelection();
_selectedFeature = null;
}
private void MapViewTapped(object sender, GeoViewInputEventArgs geoViewInputEventArgs)
{
// Get the tapped location
MapPoint tappedLocation = (MapPoint)GeometryEngine.NormalizeCentralMeridian(geoViewInputEventArgs.Location);
// Show the tapped location
_tappedLocationGraphic.Geometry = tappedLocation;
// Get the nearest vertex in the polygon
ProximityResult nearestVertexResult = GeometryEngine.NearestVertex(_polygonGraphic.Geometry, tappedLocation);
// Get the nearest coordinate in the polygon
ProximityResult nearestCoordinateResult =
GeometryEngine.NearestCoordinate(_polygonGraphic.Geometry, tappedLocation);
// Get the distance to the nearest vertex in the polygon
int distanceVertex = (int)(nearestVertexResult.Distance / 1000);
// Get the distance to the nearest coordinate in the polygon
int distanceCoordinate = (int)(nearestCoordinateResult.Distance / 1000);
// Show the nearest vertex in blue
_nearestVertexGraphic.Geometry = nearestVertexResult.Coordinate;
// Show the nearest coordinate in red
_nearestCoordinateGraphic.Geometry = nearestCoordinateResult.Coordinate;
// Show the distances in the UI
ResultsLabel.Content =
string.Format("Vertex dist: {0} km, Point dist: {1} km", distanceVertex, distanceCoordinate);
}
// calculates how far down a line a certain point on the line is located as a value from 0..1
private double GetFractionAlongLine(Polyline segment, ProximityResult proximity, MapPoint location)
{
double distance1 = 0;
double distance2 = 0;
int pointIndex = proximity.PointIndex;
int vertexCount = segment.Paths[0].Count;
var vertexPoint = segment.Paths[proximity.PartIndex][pointIndex];
Coordinate previousPoint;
int onSegmentIndex = 0;
//Detect which line segment we currently are on
if (pointIndex == 0) //Snapped to first vertex
{
onSegmentIndex = 0;
}
else if (pointIndex == vertexCount - 1) //Snapped to last vertex
{
onSegmentIndex = segment.Paths[0].Count - 2;
}
else
{
Coordinate nextPoint = segment.Paths[0][pointIndex + 1];
var d1 = GeometryEngine.DistanceFromGeometry(new MapPoint(vertexPoint, segment.SpatialReference), new MapPoint(nextPoint, segment.SpatialReference));
var d2 = GeometryEngine.DistanceFromGeometry(location, new MapPoint(nextPoint, segment.SpatialReference));
if (d1 < d2)
{
onSegmentIndex = pointIndex - 1;
}
else
{
onSegmentIndex = pointIndex;
}
}
previousPoint = segment.Paths[0][0];
for (int j = 1; j < onSegmentIndex + 1; j++)
{
Coordinate point = segment.Paths[0][j];
distance1 += GeometryEngine.DistanceFromGeometry(new MapPoint(previousPoint, segment.SpatialReference), new MapPoint(point, segment.SpatialReference));
previousPoint = point;
}
distance1 += GeometryEngine.DistanceFromGeometry(new MapPoint(previousPoint, segment.SpatialReference), location);
previousPoint = segment.Paths[0][onSegmentIndex + 1];
distance2 = GeometryEngine.DistanceFromGeometry(location, new MapPoint(previousPoint, segment.SpatialReference));
previousPoint = vertexPoint;
for (int j = onSegmentIndex + 2; j < segment.Paths[0].Count; j++)
{
Coordinate point = segment.Paths[0][j];
distance2 += GeometryEngine.DistanceFromGeometry(new MapPoint(previousPoint, segment.SpatialReference), new MapPoint(point, segment.SpatialReference));
previousPoint = point;
}
//var previousPoint = proximity.PointIndex ? segment.GetPoint(proximity.PartIndex + 1, 0) : segment.GetPoint(proximity.PartIndex, proximity.PointIndex + 1);
if (distance1 + distance2 == 0)
{
return(1);
}
return(distance1 / (distance1 + distance2));
}
// calculates how far down a line a certain point on the line is located as a value from 0..1
private double GetFractionAlongLine(Polyline segment, ProximityResult proximity, MapPoint location)
{
double distance1 = 0;
double distance2 = 0;
int pointIndex = proximity.PointIndex;
int vertexCount = segment.Parts.GetPartsAsPoints().First().Count();
var vertexPoint = segment.Parts.GetPartsAsPoints().ElementAt(proximity.PartIndex).ElementAt(pointIndex);
MapPoint previousPoint;
int onSegmentIndex = 0;
//Detect which line segment we currently are on
if (pointIndex == 0) //Snapped to first vertex
{
onSegmentIndex = 0;
}
else if (pointIndex == vertexCount - 1) //Snapped to last vertex
{
onSegmentIndex = segment.Parts.GetPartsAsPoints().First().Count() - 2;
}
else
{
MapPoint nextPoint = segment.Parts.GetPartsAsPoints().First().ElementAt(pointIndex + 1);
var d1 = GeometryEngine.Distance(vertexPoint, nextPoint);
var d2 = GeometryEngine.Distance(location, nextPoint);
if (d1 < d2)
{
onSegmentIndex = pointIndex - 1;
}
else
{
onSegmentIndex = pointIndex;
}
}
previousPoint = segment.Parts.GetPartsAsPoints().First().First();
for (int j = 1; j < onSegmentIndex + 1; j++)
{
MapPoint point = segment.Parts.GetPartsAsPoints().First().ElementAt(j);
distance1 += GeometryEngine.Distance(previousPoint, point);
previousPoint = point;
}
distance1 += GeometryEngine.Distance(previousPoint, location);
previousPoint = segment.Parts.GetPartsAsPoints().First().ElementAt(onSegmentIndex + 1);
distance2 = GeometryEngine.Distance(location, previousPoint);
previousPoint = vertexPoint;
for (int j = onSegmentIndex + 2; j < segment.Parts[0].Count; j++)
{
MapPoint point = segment.Parts.GetPartsAsPoints().First().ElementAt(j);
distance2 += GeometryEngine.Distance(previousPoint, point);
previousPoint = point;
}
//var previousPoint = proximity.PointIndex ? segment.GetPoint(proximity.PartIndex + 1, 0) : segment.GetPoint(proximity.PartIndex, proximity.PointIndex + 1);
if (distance1 + distance2 == 0)
{
return(1);
}
return(distance1 / (distance1 + distance2));
}
public static MapPoint GetNearestCoordinateInGraphicsCollection(MapPoint point, IList <Graphic> graphics)
{
ProximityResult nearest = null;
MapPoint loc = point.ToWgs84(); // :)
foreach (var graphic in graphics)
{
ProximityResult result = GeometryEngine.NearestCoordinate(graphic.Geometry, loc);
if (nearest == null || result.Distance < nearest.Distance)
{
nearest = result;
}
}
return(nearest?.Coordinate);
}
// calculates how far down a line a certain point on the line is located as a value from 0..1
private double GetFractionAlongLine(Polyline segment, ProximityResult proximity, MapPoint location)
{
double distance1 = 0;
double distance2 = 0;
int pointIndex = proximity.PointIndex;
int vertexCount = segment.Paths[0].Count;
var vertexPoint = segment.Paths[proximity.PartIndex][pointIndex];
Coordinate previousPoint;
int onSegmentIndex = 0;
//Detect which line segment we currently are on
if (pointIndex == 0) //Snapped to first vertex
onSegmentIndex = 0;
else if (pointIndex == vertexCount - 1) //Snapped to last vertex
onSegmentIndex = segment.Paths[0].Count - 2;
else
{
Coordinate nextPoint = segment.Paths[0][pointIndex + 1];
var d1 = GeometryEngine.DistanceFromGeometry(new MapPoint(vertexPoint, segment.SpatialReference), new MapPoint(nextPoint, segment.SpatialReference));
var d2 = GeometryEngine.DistanceFromGeometry(location, new MapPoint( nextPoint, segment.SpatialReference));
if (d1 < d2)
onSegmentIndex = pointIndex - 1;
else
onSegmentIndex = pointIndex;
}
previousPoint = segment.Paths[0][0];
for (int j = 1; j < onSegmentIndex + 1; j++)
{
Coordinate point = segment.Paths[0][j];
distance1 += GeometryEngine.DistanceFromGeometry(new MapPoint(previousPoint, segment.SpatialReference), new MapPoint(point, segment.SpatialReference));
previousPoint = point;
}
distance1 += GeometryEngine.DistanceFromGeometry(new MapPoint(previousPoint, segment.SpatialReference), location);
previousPoint = segment.Paths[0][onSegmentIndex + 1];
distance2 = GeometryEngine.DistanceFromGeometry(location, new MapPoint(previousPoint, segment.SpatialReference));
previousPoint = vertexPoint;
for (int j = onSegmentIndex + 2; j < segment.Paths[0].Count; j++)
{
Coordinate point = segment.Paths[0][j];
distance2 += GeometryEngine.DistanceFromGeometry(new MapPoint(previousPoint, segment.SpatialReference), new MapPoint(point, segment.SpatialReference));
previousPoint = point;
}
//var previousPoint = proximity.PointIndex ? segment.GetPoint(proximity.PartIndex + 1, 0) : segment.GetPoint(proximity.PartIndex, proximity.PointIndex + 1);
if (distance1 + distance2 == 0)
return 1;
return distance1 / (distance1 + distance2);
}
// calculates how far down a line a certain point on the line is located as a value from 0..1
private double GetFractionAlongLine(Polyline segment, ProximityResult proximity, MapPoint location)
{
double distance1 = 0;
double distance2 = 0;
int pointIndex = proximity.PointIndex;
int vertexCount = segment.Parts.GetPartsAsPoints().First().Count();
var vertexPoint = segment.Parts.GetPartsAsPoints().ElementAt(proximity.PartIndex).ElementAt(pointIndex);
MapPoint previousPoint;
int onSegmentIndex = 0;
//Detect which line segment we currently are on
if (pointIndex == 0) //Snapped to first vertex
onSegmentIndex = 0;
else if (pointIndex == vertexCount - 1) //Snapped to last vertex
onSegmentIndex = segment.Parts.GetPartsAsPoints().First().Count() - 2;
else
{
MapPoint nextPoint = segment.Parts.GetPartsAsPoints().First().ElementAt(pointIndex + 1);
var d1 = GeometryEngine.Distance(vertexPoint, nextPoint);
var d2 = GeometryEngine.Distance(location, nextPoint);
if (d1 < d2)
onSegmentIndex = pointIndex - 1;
else
onSegmentIndex = pointIndex;
}
previousPoint = segment.Parts.GetPartsAsPoints().First().First();
for (int j = 1; j < onSegmentIndex + 1; j++)
{
MapPoint point = segment.Parts.GetPartsAsPoints().First().ElementAt(j);
distance1 += GeometryEngine.Distance(previousPoint, point);
previousPoint = point;
}
distance1 += GeometryEngine.Distance(previousPoint, location);
previousPoint = segment.Parts.GetPartsAsPoints().First().ElementAt(onSegmentIndex + 1);
distance2 = GeometryEngine.Distance(location, previousPoint);
previousPoint = vertexPoint;
for (int j = onSegmentIndex + 2; j < segment.Parts[0].Count; j++)
{
MapPoint point = segment.Parts.GetPartsAsPoints().First().ElementAt(j);
distance2 += GeometryEngine.Distance(previousPoint, point);
previousPoint = point;
}
//var previousPoint = proximity.PointIndex ? segment.GetPoint(proximity.PartIndex + 1, 0) : segment.GetPoint(proximity.PartIndex, proximity.PointIndex + 1);
if (distance1 + distance2 == 0)
return 1;
return distance1 / (distance1 + distance2);
}
