Interactive Legend

This sample demonstrates the Legend control. The Legend control displays the symbology of specified Layers with text explanations of what the symbols mean in a Map an organized in a tree view hierarchy. The specific Layers that are displayed in the Legend control are controlled by what is specified in the LayersIDs Property.

For this sample, the behavior of the Legend control is transformed into an interactive Table of Contents (TOC) where the user can turn on/off as well as adjust the opacity of the individual Layer’s symbology. Adjusting the Legend control’s behavior is done by modifying the MapLayerTemplate and LayerTemplate Properties with a user defined DataTemplate. Creating a custom DataTemplate provides powerful flexibility in ‘skinning’ the Legend control to meet various needs.

XAML

<UserControl x:Class="ArcGISWPFSDK.LocalLegendWithTemplates"
    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/client/2009">
    <Grid x:Name="LayoutRoot" >
        <Grid.Resources>
            <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
            <LinearGradientBrush x:Key="PanelGradient" EndPoint="0.5,1" StartPoint="0.5,0">
                <LinearGradientBrush.RelativeTransform>
                    <TransformGroup>
                        <ScaleTransform CenterY="0.5" CenterX="0.5"/>
                        <SkewTransform CenterY="0.5" CenterX="0.5"/>
                        <RotateTransform Angle="176" CenterY="0.5" CenterX="0.5"/>
                        <TranslateTransform/>
                    </TransformGroup>
                </LinearGradientBrush.RelativeTransform>
                <GradientStop Color="#FF145787" Offset="0.16"/>
                <GradientStop Color="#FF3D7FAC" Offset="0.502"/>
                <GradientStop Color="#FF88C5EF" Offset="0.984"/>
            </LinearGradientBrush>
        </Grid.Resources>
        <esri:Map x:Name="MyMap" Extent="-15000000,2000000,-7000000,8000000" WrapAround="True" MinimumResolution="2445.98490512499">
            <esri:ArcGISLocalTiledLayer ID="myBaseMap" Path="..\\Data\\TPKs\\Topographic.tpk"/>
            <esri:ArcGISLocalDynamicMapServiceLayer ID="USA" Path="..\\Data\\MPKS\\USCitiesStates.mpk"/>
        </esri:Map>
        <Border Background="{StaticResource PanelGradient}" BorderThickness="1" CornerRadius="5"
            HorizontalAlignment="Right"  VerticalAlignment="Top"
            Margin="20" Padding="5" BorderBrush="Black" >
            <esri:Legend Map="{Binding ElementName=MyMap}"  
                         LayerIDs="USA"
                         LayerItemsMode="Tree" 
                         ShowOnlyVisibleLayers="False"
                         Refreshed="Legend_Refreshed">
                <esri:Legend.MapLayerTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <CheckBox Content="{Binding Label}"
                                    IsChecked="{Binding IsEnabled, Mode=TwoWay}"
                                    IsEnabled="{Binding IsInScaleRange}" >
                            </CheckBox>
                            <Slider Maximum="1" Value="{Binding Layer.Opacity, Mode=TwoWay}" Width="50" />
                        </StackPanel>
                    </DataTemplate>
                </esri:Legend.MapLayerTemplate>
                <esri:Legend.LayerTemplate>
                    <DataTemplate>
                        <CheckBox Content="{Binding Label}"
                            IsChecked="{Binding IsEnabled, Mode=TwoWay}"
                            IsEnabled="{Binding IsInScaleRange}" >
                        </CheckBox>
                    </DataTemplate>
                </esri:Legend.LayerTemplate>
            </esri:Legend>
        </Border>
        <ProgressBar x:Name="MyProgressBar" IsIndeterminate="True" VerticalAlignment="Bottom" Width="200" Height="20" Margin="10" Visibility="{Binding Path=IsBusy, Converter={StaticResource BooleanToVisibilityConverter}}"></ProgressBar>
    </Grid>
</UserControl>

C#

using System.Windows.Controls;
using ESRI.ArcGIS.Client.Toolkit;
using ESRI.ArcGIS.Client.Toolkit.Primitives;
using System.ComponentModel;

namespace ArcGISWPFSDK
{
    public partial class LocalLegendWithTemplates : UserControl, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private bool _isBusy = true;

        public bool IsBusy
        {
            get
            {
                return _isBusy;
            }
            set
            {
                _isBusy = value;

                if (PropertyChanged != null)
                {

                    PropertyChanged(this, new PropertyChangedEventArgs("IsBusy"));
                }
            }
        } 
    
        public LocalLegendWithTemplates()
        {
            InitializeComponent();

            DataContext = this;

            MyMap.Layers.LayersInitialized += (o, evt) =>
            {
                IsBusy = false;

            };
        }

        private void Legend_Refreshed(object sender, Legend.RefreshedEventArgs e)
        {
            LayerItemViewModel removeLayerItemVM = null;

            if (e.LayerItem.LayerItems != null)
            {
                foreach (LayerItemViewModel layerItemVM in e.LayerItem.LayerItems)
                {
                    if (layerItemVM.IsExpanded)
                        layerItemVM.IsExpanded = false;

                    if (layerItemVM.Label == "states")
                        removeLayerItemVM = layerItemVM;
                }

                if (removeLayerItemVM != null)
                    e.LayerItem.LayerItems.Remove(removeLayerItemVM);
            }
            else
            {
                e.LayerItem.IsExpanded = false;
            }
        }
    }
}

VB.NET

Imports System.Windows.Controls
Imports ESRI.ArcGIS.Client.Toolkit
Imports ESRI.ArcGIS.Client.Toolkit.Primitives
Imports System.ComponentModel

Namespace ArcGISWPFSDK
    Partial Public Class LocalLegendWithTemplates
        Inherits UserControl
        Implements INotifyPropertyChanged
        Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged
        Private _isBusy As Boolean = True
        Public Property IsBusy() As Boolean
            Get
                Return _isBusy
            End Get
            Set(value As Boolean)
                _isBusy = value
                RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("IsBusy"))
            End Set
        End Property
        Public Sub New()
            InitializeComponent()
            AddHandler MyMap.Layers.LayersInitialized, AddressOf map_LayersInitialized
        End Sub
        Private Sub map_LayersInitialized(sender As Object, e As EventArgs)
            DataContext = Me
            IsBusy = False
        End Sub
        Private Sub Legend_Refreshed(sender As Object, e As Legend.RefreshedEventArgs)
            Dim removeLayerItemVM As LayerItemViewModel = Nothing

            If e.LayerItem.LayerItems IsNot Nothing Then
                For Each layerItemVM As LayerItemViewModel In e.LayerItem.LayerItems
                    If layerItemVM.IsExpanded Then
                        layerItemVM.IsExpanded = False
                    End If

                    If layerItemVM.Label = "states" Then
                        removeLayerItemVM = layerItemVM
                    End If
                Next

                If removeLayerItemVM IsNot Nothing Then
                    e.LayerItem.LayerItems.Remove(removeLayerItemVM)
                End If
            Else
                e.LayerItem.IsExpanded = False
            End If
        End Sub
    End Class
End Namespace