Use a symbol style to display a graphic on a graphics overlay.
      
  
    
Use case
Allows you to customize a graphic by assigning a unique symbol. For example, you may wish to display individual graphics for different landmarks across a region, and to style each one with a unique symbol.
How to use the sample
Observe the graphics on the map.
How it works
- Create a 
GraphicsOverlayand add it to theMapView. - Create a 
Symbolsuch asSimpleMarkerSymbol,SimpleLineSymbolorSimpleFillSymbol. - Create a 
Graphic, specifying aGeometryand aSymbol. - Add the 
Graphicto theGraphicsOverlay. 
Relevant API
- Geometry
 - Graphic
 - GraphicsOverlay
 - SimpleFillSymbol
 - SimpleLineSymbol
 - SimpleMarkerSymbol
 
Additional information
To set a symbol style across a number of graphics (e.g. showing trees as graphics sharing a symbol in a park), see the "Add graphics with renderer" sample.
Tags
SimpleFillSymbol, SimpleLineSymbol, SimpleMarkerSymbol
Sample Code
AddGraphicsWithSymbols.cs
// 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 Android.App;
using Android.OS;
using Android.Widget;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using Esri.ArcGISRuntime.UI.Controls;
using System.Drawing;
namespace ArcGISRuntime.Samples.AddGraphicsWithSymbols
{
    [Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Add graphics with symbols",
        category: "GraphicsOverlay",
        description: "Use a symbol style to display a graphic on a graphics overlay.",
        instructions: "Observe the graphics on the map.",
        tags: new[] { "SimpleFillSymbol", "SimpleLineSymbol", "SimpleMarkerSymbol" })]
    public class AddGraphicsWithSymbols : Activity
    {
        // Hold a reference to the map view
        private MapView _myMapView;
        // Create the graphics overlay
        private readonly GraphicsOverlay _overlay = new GraphicsOverlay();
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
            Title = "Add graphics with symbols";
            // Create the UI, setup the control references and execute initialization
            CreateLayout();
            Initialize();
        }
        private void Initialize()
        {
            // Create the map
            Map myMap = new Map(BasemapStyle.ArcGISOceans);
            myMap.InitialViewpoint = new Viewpoint(56.075844, -2.681572, 14);
            // Add the map to the map view
            _myMapView.Map = myMap;
            // Add the graphics overlay to the map view
            _myMapView.GraphicsOverlays.Add(_overlay);
            // Call functions to create the graphics
            CreatePoints();
            CreatePolygon();
            CreatePolyline();
            CreateText();
            // Update the extent to encompass all of the symbols
            SetExtent();
        }
        private void CreatePoints()
        {
            // Create a red circle simple marker symbol
            SimpleMarkerSymbol redCircleSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Circle, Color.Red, 10);
            // Create graphics and add them to graphics overlay
            Graphic graphic = new Graphic(new MapPoint(-2.72, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);
            graphic = new Graphic(new MapPoint(-2.69, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);
            graphic = new Graphic(new MapPoint(-2.66, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);
            graphic = new Graphic(new MapPoint(-2.63, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);
        }
        private void CreatePolyline()
        {
            // Create a purple simple line symbol
            SimpleLineSymbol lineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Dash, Color.Purple, 4);
            // Create a new point collection for polyline
            PointCollection points = new PointCollection(SpatialReferences.Wgs84)
            {
                // Create and add points to the point collection
                new MapPoint(-2.715, 56.061),
                new MapPoint(-2.6438, 56.079),
                new MapPoint(-2.638, 56.079),
                new MapPoint(-2.636, 56.078),
                new MapPoint(-2.636, 56.077),
                new MapPoint(-2.637, 56.076),
                new MapPoint(-2.715, 56.061)
            };
            // Create the polyline from the point collection
            Polyline polyline = new Polyline(points);
            // Create the graphic with polyline and symbol
            Graphic graphic = new Graphic(polyline, lineSymbol);
            // Add graphic to the graphics overlay
            _overlay.Graphics.Add(graphic);
        }
        private void CreatePolygon()
        {
            // Create a green simple line symbol
            SimpleLineSymbol outlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Dash, Color.Green, 1);
            // Create a green mesh simple fill symbol
            SimpleFillSymbol fillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.DiagonalCross, Color.Green, outlineSymbol);
            // Create a new point collection for polygon
            PointCollection points = new PointCollection(SpatialReferences.Wgs84)
            {
                // Create and add points to the point collection
                new MapPoint(-2.6425, 56.0784),
                new MapPoint(-2.6430, 56.0763),
                new MapPoint(-2.6410, 56.0759),
                new MapPoint(-2.6380, 56.0765),
                new MapPoint(-2.6380, 56.0784),
                new MapPoint(-2.6410, 56.0786)
            };
            // Create the polyline from the point collection
            Polygon polygon = new Polygon(points);
            // Create the graphic with polyline and symbol
            Graphic graphic = new Graphic(polygon, fillSymbol);
            // Add graphic to the graphics overlay
            _overlay.Graphics.Add(graphic);
        }
        private void CreateText()
        {
            // Create two text symbols
            TextSymbol bassRockTextSymbol = new TextSymbol("Black Rock", Color.Blue, 10,
                HorizontalAlignment.Left, VerticalAlignment.Bottom);
            TextSymbol craigleithTextSymbol = new TextSymbol("Craigleith", Color.Blue, 10,
                HorizontalAlignment.Right, VerticalAlignment.Top);
            // Create two points
            MapPoint bassPoint = new MapPoint(-2.64, 56.079, SpatialReferences.Wgs84);
            MapPoint craigleithPoint = new MapPoint(-2.72, 56.076, SpatialReferences.Wgs84);
            // Create two graphics from the points and symbols
            Graphic bassRockGraphic = new Graphic(bassPoint, bassRockTextSymbol);
            Graphic craigleithGraphic = new Graphic(craigleithPoint, craigleithTextSymbol);
            // Add graphics to the graphics overlay
            _overlay.Graphics.Add(bassRockGraphic);
            _overlay.Graphics.Add(craigleithGraphic);
        }
        private void SetExtent()
        {
            // Get all of the graphics contained in the graphics overlay
            GraphicCollection myGraphicCollection = _overlay.Graphics;
            // Create a new envelope builder using the same spatial reference as the graphics
            EnvelopeBuilder myEnvelopeBuilder = new EnvelopeBuilder(SpatialReferences.Wgs84);
            // Loop through each graphic in the graphic collection
            foreach (Graphic oneGraphic in myGraphicCollection)
            {
                // Union the extent of each graphic in the envelope builder
                myEnvelopeBuilder.UnionOf(oneGraphic.Geometry.Extent);
            }
            // Expand the envelope builder by 30%
            myEnvelopeBuilder.Expand(1.3);
            // Adjust the viewable area of the map to encompass all of the graphics in the
            // graphics overlay plus an extra 30% margin for better viewing
            _myMapView.SetViewpointAsync(new Viewpoint(myEnvelopeBuilder.Extent));
        }
        private void CreateLayout()
        {
            // Create a new vertical layout for the app
            LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
            // Add the map view to the layout
            _myMapView = new MapView(this);
            layout.AddView(_myMapView);
            // Show the layout in the app
            SetContentView(layout);
        }
    }
}