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ArcGIS Runtime SDK for .NET

Add graphics with renderer

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

Change the style of all graphics in a graphics overlay by referencing a single symbol style.

screenshot

Use case

A renderer allows you to change the style of all graphics in an overlay by only changing one copy of the symbol. For example, a user may wish to display a number of graphics on a map of parkland which represent trees, all sharing a common symbol.

How it works

  1. Create a GraphicsOverlay and add it to the MapView.
  2. Create a Graphic, specifying only a Geometry.
  3. Create a single Symbol such as a SimpleMarkerSymbol.
  4. Create a renderer with the Symbol such as new SimpleRenderer(symbol).
  5. Set the renderer on the GraphicsOverlay with graphicsOverlay.Renderer = renderer.

Relevant API

  • Geometry
  • Graphic
  • GraphicsOverlay
  • SimpleFillSymbol
  • SimpleLineSymbol
  • SimpleMarkerSymbol
  • SimpleRenderer

Additional information

A renderer will only effect graphics that do not specify their own symbol style.

To set unique symbols across a number of graphics (e.g. showing graphics of individual landmarks) see "Add graphics with symbols" sample.

Tags

GraphicsOverlay, SimpleMarkerSymbol, SimpleRenderer

Sample Code

<UserControl
    x:Class="ArcGISRuntime.UWP.Samples.AddGraphicsRenderer.AddGraphicsRenderer"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:esriUI="using:Esri.ArcGISRuntime.UI.Controls"
    mc:Ignorable="d"
    d:DesignHeight="300"
    d:DesignWidth="400">

    <Grid>
        <esriUI:MapView x:Name="MyMapView"/>
    </Grid>
</UserControl>
// Copyright 2016 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 System;
using System.Drawing;

namespace ArcGISRuntime.UWP.Samples.AddGraphicsRenderer
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Add graphics (SimpleRenderer)",
        "GraphicsOverlay",
        "This sample demonstrates how you add graphics and set a renderer on a graphic overlays.",
        "")]
    public sealed partial class AddGraphicsRenderer
    {
        public AddGraphicsRenderer()
        {
            InitializeComponent();

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

        private void Initialize()
        {
            // Create a map with 'Imagery with Labels' basemap and an initial location
            Map myMap = new Map(BasemapType.ImageryWithLabels, 34.056295, -117.195800, 14);

            // Create graphics when MapView's viewpoint is initialized
            MyMapView.ViewpointChanged += OnViewpointChanged;

            // Assign the map to the MapView
            MyMapView.Map = myMap;
        }

        private void OnViewpointChanged(object sender, EventArgs e)
        {
            // Unhook the event
            MyMapView.ViewpointChanged -= OnViewpointChanged;

            // Get area that is shown in a MapView
            Polygon visibleArea = MyMapView.VisibleArea;

            // Get extent of that area
            Envelope extent = visibleArea.Extent;

            // Get central point of the extent
            MapPoint centerPoint = extent.GetCenter();

            // Create values inside the visible extent for creating graphic
            double extentWidth = extent.Width / 5;
            double extentHeight = extent.Height / 10;

            // Create point collection
            PointCollection points = new PointCollection(SpatialReferences.WebMercator)
                {
                    new MapPoint(centerPoint.X - extentWidth * 2, centerPoint.Y - extentHeight * 2),
                    new MapPoint(centerPoint.X - extentWidth * 2, centerPoint.Y + extentHeight * 2),
                    new MapPoint(centerPoint.X + extentWidth * 2, centerPoint.Y + extentHeight * 2),
                    new MapPoint(centerPoint.X + extentWidth * 2, centerPoint.Y - extentHeight * 2)
                };

            // Create overlay to where graphics are shown
            GraphicsOverlay overlay = new GraphicsOverlay();

            // Add points to the graphics overlay
            foreach (MapPoint point in points)
            {
                // Create new graphic and add it to the overlay
                overlay.Graphics.Add(new Graphic(point));
            }

            // Create symbol for points
            SimpleMarkerSymbol pointSymbol = new SimpleMarkerSymbol()
            {
                Color = Color.Yellow,
                Size = 30,
                Style = SimpleMarkerSymbolStyle.Square
            };

            // Create simple renderer with symbol
            SimpleRenderer renderer = new SimpleRenderer(pointSymbol);

            // Set renderer to graphics overlay
            overlay.Renderer = renderer;

            // Add created overlay to the MapView
            MyMapView.GraphicsOverlays.Add(overlay);
        }
    }
}