Keeping layer checkbox in sync with layer visibility - SL3 to SL4 issue

[MatthewCarey]

I have an application that reuses the code from ESRI's 'SubLayer List' sample to populate a listbox with checkboxes to turn each sublayer of the map service on and off (also known as a TOC).

After certain events I turn on a sublayer programmatically. In the Silverlight 3 version of my app I used a method called UpdateLayerList (which I believe was part of an earlier ESRI sample) that would repopulate the listbox and made sure that the checkboxes reflected the visible/not visible status of the sublayers.

In translating the app to Silverlight 4 and looking at the latest sample, the UpdateLayerList method apparently became unnecessary, and now if I try to make use of it the list box becomes blank.

I can still turn on a sublayer programmatically with no issues, but cannot figure out a way to either refresh the TOC with the checkboxes reflecting the sublayers' actual visibility, or at least say specifically "turn on this checkbox for this layer."

I believe the binding process may be part of the answer or there's something else that I'm missing, so any help would be greatly appreciated! Thanks.

[JenniferNery]

One way of achieving this is to create your own class MyLayerInfo with additional property IsVisible, using an ObservableCollection of this type as ItemsSource for your listbox, and adding a method that updates IsVisible property by checking dynamic layer's VisibleLayers.

Xaml-code:  (update ListBox)

 <ListBox x:Name="SubLayerListBox" Margin="0,5,0,0"  
                         Grid.Row="1">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <CheckBox Margin="2"
                                  Name="DynamicLayerCalifornia"
                                  Content="{Binding LayerInfo.Name}" 
                                  IsChecked="{Binding IsVisible}" 
                                  Tag="{Binding LayerInfo.ID}"
                                  ClickMode="Press" 
                                  Click="CheckBox_Click" />
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>

Code-behind: (update ListBox' ItemsSource)

        ObservableCollection<MyLayerInfo> MySubLayers = new ObservableCollection<MyLayerInfo>();
        public SubLayerList()
        {
            InitializeComponent();
            this.SubLayerListBox.ItemsSource = MySubLayers;
        }

        private void ArcGISDynamicMapServiceLayer_Initialized(object sender, EventArgs e)
        {
            ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer dynamicServiceLayer =
                sender as ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer;
   foreach (LayerInfo l in dynamicServiceLayer.Layers)
    MySubLayers.Add(new MyLayerInfo(l));
            if (dynamicServiceLayer.VisibleLayers == null)
                dynamicServiceLayer.VisibleLayers = GetDefaultVisibleLayers(dynamicServiceLayer);
 UpdateIsVisibleProperty(dynamicServiceLayer.VisibleLayers.ToList());
        }

//TODO: call this method everytime dynamicServiceLayer.VisibleLayers is updated
        private void UpdateIsVisibleProperty(List<int> visibleLayerList)
        {
            foreach (MyLayerInfo info in MySubLayers)
                info.IsVisible = visibleLayerList.Contains(info.LayerInfo.ID);
        }

 public class MyLayerInfo : INotifyPropertyChanged
 {
  public MyLayerInfo(LayerInfo info)
  {
   LayerInfo = info;
  }
  private LayerInfo layerInfo;
  public LayerInfo LayerInfo
  {
   get { return layerInfo; }
   set
   {
    if (layerInfo != value)
    {
     layerInfo = value;
     if (PropertyChanged != null)
      PropertyChanged(this, new PropertyChangedEventArgs("LayerInfo"));
    }
   }
  }
  bool isVisible;
  public bool  IsVisible
  {
   get { return isVisible; }
   set
   {
    if (isVisible != value)
    {
     isVisible = value;
     if (PropertyChanged != null)
      PropertyChanged(this, new PropertyChangedEventArgs("IsVisible"));
    }
   }
  }
  public event PropertyChangedEventHandler PropertyChanged;
 }

[MatthewCarey]

This solution worked fine for me - thanks a lot for your help!

[AnastasiaAourik]

I would like to generate a list box that shows the layers in mulitiple map services.
Plus, I will only include the layers that do not have the word 'label' in the layername.

The sample and binding you have shown works well for a single map service.

Can anyone help with buiding this for mulitiple map services...

I have started by creating a class AllWellsLayerInfo : INotifyPropertyChanged

and have attributes
LayerInfo, and isVisible
that fires a propertychangedEvent on those 2 fields, respectively.

Can someone direct me to a solution...

[RobertBrodsky]

Hi;
Try using this.

ScrollViewer see example below

<userControls:WindowPanel x:Name="LayersPanel"
   IsOpen="{Binding ElementName=btnToggleLayerList, Path=IsChecked, Mode=TwoWay}"
      HorizontalAlignment="Right" VerticalAlignment="Top" Width="233" Height="393"
   Margin="0,68,6,0">

            <ScrollViewer Width="207" Height="355" Padding="0">
                <ListBox ItemsSource="{Binding ElementName=Map, Path=Layers.[XXXXX].Layers}"
                         x:Name="SubLayerListBox">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <CheckBox Margin="2"
                                  Name="XXX Layers"
                                  Content="{Binding Name}"
                                  IsChecked="{Binding DefaultVisibility, Mode=TwoWay}"
                                  Tag="{Binding ID}"
                                  ClickMode="Press"
                                  Click="LayersCheckBox_Click"
                                  />
                    </DataTemplate>
                </ListBox.ItemTemplate>
                </ListBox>
            </ScrollViewer>

            <userControls:WindowPanel.ContentTitle>
                <StackPanel Orientation="Horizontal">
                    <Image Source="Images/Layers-32.png"
                           HorizontalAlignment="Left" VerticalAlignment="Top" Stretch="Fill"
                           Width="20" Height="20" Margin="5,2,0,0" />
                    <TextBlock Foreground="White" FontSize="12"
                               Text="PERA Layers" Width="100" TextWrapping="NoWrap" Height="Auto"
                               HorizontalAlignment="Left" Margin="5,3,0,0" />
                </StackPanel>
            </userControls:WindowPanel.ContentTitle>
        </userControls:WindowPanel>

[JenniferNery]

To use with multiple map services, you can subscribe to the same ArcGISDynamicMapServiceLayer_Initialized event in Post#2. And modify it so that you can exclude sublayers that contains 'label' in their name.

foreach (LayerInfo l in dynamicServiceLayer.Layers)
{
 if(!l.Name.Contains("label)")
  MySubLayers.Add(new MyLayerInfo(l));
}