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ArcGIS Runtime SDK for .NET

Simple renderer

This code sample is available for these platforms:
View Sample on GitHub

Display common symbols for all graphics in a graphics overlay with a renderer.

Image of simple renderer

Use case

Graphics are often used to display data that changes location regularly because they are held in memory instead of being persisted to the map. When a number of graphics are required to share the same style, a simple renderer can be applied to the graphics overlay containing the graphics. For example, the location of mobile taxis from a same company could be plotted on a map with each taxi marked by a relevant symbol.

How to use the sample

The sample loads with a predefined simple renderer, which displays a red cross simple marker symbol for the graphics in the graphics overlay.

How it works

  1. Create a GraphicsOverlay.
  2. Create a number of Point objects with x, y and spatial reference parameters.
  3. Create a SimpleMarkerSymbol passing in a SimpleMarkerSymbol.Style, color and size as parameters.
  4. Create a simple renderer with SimpleRenderer(simpleMarkerSymbol).
  5. Set the simple renderer to the graphics overlay using graphicsOverlay.setRenderer(simpleRenderer).
  6. Create a number of Graphic objects with the points initiated in step 2.
  7. Add the graphics to the graphics overlay with graphicsOverlay.Graphics.Add(graphic).

Relevant API

  • Graphic
  • GraphicsOverlay
  • Point
  • SimpleMarkerSymbol
  • SimpleRenderer

Additional information

Renderers are used to display graphics that don't already have a symbol set. A renderer will not override a graphic's symbol if one has been set.

Tags

graphics, marker, renderer, symbol, symbolize, symbology

Sample Code

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"             
             xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms"
             xmlns:mapping="clr-namespace:Esri.ArcGISRuntime.Mapping;assembly=Esri.ArcGISRuntime" 
             x:Class="ArcGISRuntime.Samples.SimpleRenderers.SimpleRenderers">
  <Grid>
    <esriUI:MapView x:Name="MyMapView"/>
  </Grid>
</ContentPage>
// Copyright 2017 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 Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using Xamarin.Forms;
using Colors = System.Drawing.Color;

namespace ArcGISRuntime.Samples.SimpleRenderers
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Simple renderer",
        category: "Symbology",
        description: "Display common symbols for all graphics in a graphics overlay with a renderer.",
        instructions: "The sample loads with a predefined simple renderer, which displays a red cross simple marker symbol for the graphics in the graphics overlay.",
        tags: new[] { "graphics", "marker", "renderer", "symbol", "symbolize", "symbology" })]
    public partial class SimpleRenderers : ContentPage
    {
        public SimpleRenderers()
        {
            InitializeComponent();

            // Create the UI, setup the control references and execute initialization.
            Initialize();
        }

        private void Initialize()
        {
            // Create new map with basemap layer.
            Map myMap = new Map(Basemap.CreateImageryWithLabels());

            // Create several map points using the WGS84 coordinates (latitude and longitude).
            MapPoint oldFaithfulPoint = new MapPoint(-110.828140, 44.460458, SpatialReferences.Wgs84);
            MapPoint cascadeGeyserPoint = new MapPoint(-110.829004, 44.462438, SpatialReferences.Wgs84);
            MapPoint plumeGeyserPoint = new MapPoint(-110.829381, 44.462735, SpatialReferences.Wgs84);

            // Use the two points farthest apart to create an envelope.
            Envelope initialEnvelope = new Envelope(oldFaithfulPoint, plumeGeyserPoint);

            // Use the envelope to define the map views visible area (include some padding around the extent).
            myMap.InitialViewpoint = new Viewpoint(initialEnvelope);

            // Add the map to the map view.
            MyMapView.Map = myMap;

            // Set the viewpoint to the envelope with padding.
            MyMapView.SetViewpointGeometryAsync(initialEnvelope, 50);

            // Create a graphics overlay .
            GraphicsOverlay myGraphicOverlay = new GraphicsOverlay();

            // Create graphics based upon the map points.
            Graphic oldFaithfulGraphic = new Graphic(oldFaithfulPoint);
            Graphic cascadeGeyserGraphic = new Graphic(cascadeGeyserPoint);
            Graphic plumeGeyserGraphic = new Graphic(plumeGeyserPoint);

            // Add the graphics to the graphics overlay.
            myGraphicOverlay.Graphics.Add(oldFaithfulGraphic);
            myGraphicOverlay.Graphics.Add(cascadeGeyserGraphic);
            myGraphicOverlay.Graphics.Add(plumeGeyserGraphic);

            // Create a simple marker symbol - red, cross, size 12.
            SimpleMarkerSymbol mySymbol = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Cross, Colors.Red, 12);

            // Create a simple renderer based on the simple marker symbol.
            SimpleRenderer myRenderer = new SimpleRenderer(mySymbol);

            // Apply the renderer to the graphics overlay (all graphics use the same symbol).
            myGraphicOverlay.Renderer = myRenderer;

            // Add the graphics overlay to the map view.
            MyMapView.GraphicsOverlays.Add(myGraphicOverlay);
        }
    }
}