Geodesic operations

Calculate a geodesic path between two points and measure its distance.

Use case

A geodesic distance provides an accurate, real-world distance between two points. Visualizing flight paths between cities is a common example of a geodesic operation since the flight path between two airports takes into account the curvature of the earth, rather than following the planar path between those points, which appears as a straight line on a projected map.

How to use the sample

Tap anywhere on the map. A line graphic will display the geodesic line between the two points. In addition, text that indicates the geodesic distance between the two points will be updated. Tap elsewhere and a new line will be created.

How it works

1. A Point is created in New York City and displayed as a Graphic.
2. When a tap occurs on the MapView, a new Point is obtained from the mouse click. This Point is added as a Graphic.
3. A Polyline is created with the two Point objects.
4. GeometryEngine.DensifyGeodetic is executed by passing in the Polyline object, and the returned Geometry is added as a Graphic.
5. GeometryEngine.LengthGeodetic is executed by passing in the two Point objects, and the returned number is displayed on the screen.

Relevant API

• GeometryEngine.DensifyGeodetic
• GeometryEngine.LengthGeodetic

About the data

The Imagery basemap provides the global context for the displayed geodesic line.

Tags

densify, distance, geodesic, geodetic

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage x:Class="ArcGISRuntime.Samples.GeodesicOperations.GeodesicOperations"
             xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:forms="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Label x:Name="ResultsLabel"
               Grid.Row="0"
               HorizontalTextAlignment="Center"
               TextColor="Red">
            Tap to set an end point.
        </Label>
        <forms:MapView x:Name="MyMapView" Grid.Row="1" />
    </Grid>
</ContentPage>