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LinearUnit Class

Represents a linear unit of measure used by a Geometry or SpatialReference, or in measurement conversion functions.
Inheritance Hierarchy

Namespace:  Esri.ArcGISRuntime.Geometry
Assembly:  Esri.ArcGISRuntime (in Esri.ArcGISRuntime.dll) Version: 100.9.0
Syntax
public sealed class LinearUnit : Unit

The LinearUnit type exposes the following members.

Properties
  NameDescription
Public propertyCode exampleAbbreviation
Gets the abbreviation of the unit.
(Inherited from Unit.)
Public propertyDisplayName
Gets the display name of the unit.
(Inherited from Unit.)
Public propertyName
Gets the name of the unit.
(Inherited from Unit.)
Public propertyCode examplePluralDisplayName
Retrieve the plural display name of the unit.
(Inherited from Unit.)
Public propertyUnitId
Gets the well-known ID of the unit.
(Inherited from Unit.)
Public propertyUnitType
Returns the type of unit.
(Overrides UnitUnitType.)
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Methods
  NameDescription
Public methodConvertFrom
Converts a value in another unit of measure into this unit of measure.
Public methodCode exampleConvertTo
Converts a value in this unit of measure into another unit of measure.
Public methodStatic memberCreateFromAreaUnit
Creates a linear unit from a corresponding area unit. For example square meters will become meters.
Public methodFromMeters
Converts a meter value to this unit of measure.
Public methodIsEqual
Returns true of the Unit instances are the same.
(Inherited from Unit.)
Public methodCode exampleToMeters
Converts a value in this unit of measure to meters.
Public methodToString
Returns a String that represents this instance.
(Overrides ObjectToString.)
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Examples

WPF

Example Name: Buffer

Create a buffer around a map point and display the results as a `Graphic`

Code example screen shot.

C#
// Copyright 2018 Esri.
// 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.

using System.Windows;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using System.Drawing;

namespace ArcGISRuntime.WPF.Samples.Buffer
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Buffer",
        category: "Geometry",
        description: "Create a buffer around a map point and display the results as a `Graphic`",
        instructions: "1. Tap on the map.",
        tags: new[] { "analysis", "buffer", "euclidean", "geodesic", "geometry", "planar" })]
    public partial class Buffer
    {
        public Buffer()
        {
            InitializeComponent();

            // Initialize the map and graphics overlays.
            Initialize();
        }

        private void Initialize()
        {
            // Create a map with a topographic basemap and add it to the map view.
            MyMapView.Map = new Map(Basemap.CreateTopographic());

            // Handle the MapView's GeoViewTapped event to create buffers.
            MyMapView.GeoViewTapped += MyMapView_GeoViewTapped;

            // Create a fill symbol for geodesic buffer polygons.            
            Color geodesicBufferColor = Color.FromArgb(120, 255, 0, 0);
            SimpleLineSymbol geodesicOutlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, geodesicBufferColor, 2);
            SimpleFillSymbol geodesicBufferFillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, geodesicBufferColor, geodesicOutlineSymbol);

            // Create a fill symbol for planar buffer polygons.            
            Color planarBufferColor = Color.FromArgb(120, 0, 0, 255);
            SimpleLineSymbol planarOutlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, planarBufferColor, 2);
            SimpleFillSymbol planarBufferFillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, planarBufferColor, planarOutlineSymbol);

            // Create a marker symbol for tap locations.
            SimpleMarkerSymbol tapSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Cross, Color.White, 14);

            // Create a graphics overlay to display geodesic polygons, set its renderer and add it to the map view.
            GraphicsOverlay geodesicPolysOverlay = new GraphicsOverlay
            { 
                Id = "GeodesicPolys",
                Renderer = new SimpleRenderer(geodesicBufferFillSymbol)
            };
            MyMapView.GraphicsOverlays.Add(geodesicPolysOverlay);

            // Create a graphics overlay to display planar polygons, set its renderer and add it to the map view.
            GraphicsOverlay planarPolysOverlay = new GraphicsOverlay
            {
                Id = "PlanarPolys",
                Renderer = new SimpleRenderer(planarBufferFillSymbol)
            };
            MyMapView.GraphicsOverlays.Add(planarPolysOverlay);

            // Create a graphics overlay to display tap locations for buffers, set its renderer and add it to the map view.
            GraphicsOverlay tapLocationsOverlay = new GraphicsOverlay
            {
                Id = "TapPoints",
                Renderer = new SimpleRenderer(tapSymbol)
            };
            MyMapView.GraphicsOverlays.Add(tapLocationsOverlay);

            // Show the colors for each type of buffer in the UI.
            ShowBufferSwatches(planarBufferColor, geodesicBufferColor);
        }

        private void MyMapView_GeoViewTapped(object sender, Esri.ArcGISRuntime.UI.Controls.GeoViewInputEventArgs e)
        {
            try
            {
                // Get the location tapped by the user (a map point in the WebMercator projected coordinate system).
                MapPoint userTapPoint = e.Location;

                // Get the buffer distance (miles) entered in the text box.
                double bufferInMiles = System.Convert.ToDouble(BufferDistanceMilesTextBox.Text);

                // Call a helper method to convert the input distance to meters.
                double bufferInMeters = LinearUnits.Miles.ToMeters(bufferInMiles);

                // Create a planar buffer graphic around the input location at the specified distance.
                Geometry bufferGeometryPlanar = GeometryEngine.Buffer(userTapPoint, bufferInMeters);
                Graphic planarBufferGraphic = new Graphic(bufferGeometryPlanar);

                // Create a geodesic buffer graphic using the same location and distance.
                Geometry bufferGeometryGeodesic = GeometryEngine.BufferGeodetic(userTapPoint, bufferInMeters, LinearUnits.Meters, double.NaN, GeodeticCurveType.Geodesic);
                Graphic geodesicBufferGraphic = new Graphic(bufferGeometryGeodesic);

                // Create a graphic for the user tap location.
                Graphic locationGraphic = new Graphic(userTapPoint); 

                // Get the graphics overlays.
                GraphicsOverlay planarBufferGraphicsOverlay = MyMapView.GraphicsOverlays["PlanarPolys"];
                GraphicsOverlay geodesicBufferGraphicsOverlay = MyMapView.GraphicsOverlays["GeodesicPolys"];
                GraphicsOverlay tapPointGraphicsOverlay = MyMapView.GraphicsOverlays["TapPoints"];

                // Add the buffer polygons and tap location graphics to the appropriate graphic overlays.
                planarBufferGraphicsOverlay.Graphics.Add(planarBufferGraphic);
                geodesicBufferGraphicsOverlay.Graphics.Add(geodesicBufferGraphic);
                tapPointGraphicsOverlay.Graphics.Add(locationGraphic);
            }
            catch (System.Exception ex)
            {
                // Display an error message if there is a problem generating the buffers.
                MessageBox.Show(ex.Message, "Error creating buffers");
            }
        }

        private void ShowBufferSwatches(Color planarBufferColor, Color geodesicBufferColor)
        {
            // Create an equivalent System.Windows.Media.Color for each of the buffer symbol colors (System.Drawing.Color).
            System.Windows.Media.Color planarLabelColor = System.Windows.Media.Color.FromArgb(
                planarBufferColor.A,
                planarBufferColor.R,
                planarBufferColor.G,
                planarBufferColor.B);
            System.Windows.Media.Color geodesicLabelColor = System.Windows.Media.Color.FromArgb(
                geodesicBufferColor.A,
                geodesicBufferColor.R,
                geodesicBufferColor.G,
                geodesicBufferColor.B);

            // Show buffer symbol colors in the UI by setting the appropriate Ellipse object fill color.
            BufferSwatchPlanarEllipse.Fill = new System.Windows.Media.SolidColorBrush(planarLabelColor);
            BufferSwatchGeodesicEllipse.Fill = new System.Windows.Media.SolidColorBrush(geodesicLabelColor);
        }

        private void ClearBuffersButton_Click(object sender, RoutedEventArgs e)
        {
            // Clear the buffer and point graphics.
            foreach (GraphicsOverlay ov in MyMapView.GraphicsOverlays)
            {
                ov.Graphics.Clear();
            }
        }
    }
}
XAML
<UserControl x:Class="ArcGISRuntime.WPF.Samples.Buffer.Buffer"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:esri="http://schemas.esri.com/arcgis/runtime/2013">
    <Grid>
        <esri:MapView x:Name="MyMapView" />
        <Border Style="{StaticResource BorderStyle}">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <Label Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3"
                       HorizontalContentAlignment="Center"
                       FontWeight="SemiBold"
                       Content="Click the map to create planar and geodesic buffers." />
                <Label Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2"
                       HorizontalAlignment="Right"
                       Content="Buffer distance (miles):" />
                <TextBox x:Name="BufferDistanceMilesTextBox"
                         Grid.Row="1" Grid.Column="2"
                         TextAlignment="Right" VerticalContentAlignment="Center"
                         MinWidth="80"
                         Text="1000" />
                <Ellipse x:Name="BufferSwatchPlanarEllipse"
                         Grid.Row="2" Grid.Column="0"
                         Stroke="LightGray"
                         Width="20" Height="20" />
                <Label Grid.Row="2" Grid.Column="1"
                       HorizontalAlignment="Left"
                       Content="Planar buffers (Web Mercator)" />
                <Ellipse x:Name="BufferSwatchGeodesicEllipse"
                         Grid.Row="3" Grid.Column="0"
                         Stroke="LightGray"
                         Width="20" Height="20" />
                <Label Grid.Row="3" Grid.Column="1"
                       HorizontalAlignment="Left"
                       Content="Geodesic buffers" />
                <Button x:Name="ClearBuffersButton"
                        Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="3"
                        Margin="0,10,0,0"
                        Content="Clear"
                        Click="ClearBuffersButton_Click" />
            </Grid>
        </Border>
    </Grid>
</UserControl>
See Also
Additional Examples
Hyperlink to ExampleDescription
BufferCreate a buffer around a map point and display the results as a `Graphic`
BufferListGenerate multiple individual buffers or a single unioned buffer around multiple points.
DistanceMeasurementMeasure distances between two points in 3D.
GenerateOfflineMapWithOverridesTake a web map offline with additional options for each layer.
GeodesicOperationsCalculate a geodesic path between two points and measure its distance.
LineOfSightGeoElementShow a line of sight between two moving objects.
NavigateRouteUse a routing service to navigate between points.
NavigateRouteReroutingNavigate between two points and dynamically recalculate an alternate route when the original route is unavailable.
RouteAroundBarriersFind a route that reaches all stops without crossing any barriers.
ViewshedGeoElementAnalyze the viewshed for an object (GeoElement) in a scene.