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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.

screenshot

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

SimpleMarkerSymbol, SimpleRenderer, 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(
        "Simple renderer",
        "Symbology",
        "This sample demonstrates how to create a simple renderer and add it to a graphics overlay. Renderers define the symbology for all graphics in a graphics overlay (unless they are overridden by setting the symbol directly on the graphic). Simple renderers can also be defined on feature layers using the same code.",
        "")]
    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);
        }
    }
}