topic Re: How to binding mainpage's map? in ArcGIS API for Silverlight Questions

How to binding mainpage's map?

ShaningYu — Wed, 27 Oct 2010 12:54:49 GMT

Title should be How to bind to MainPage's map?
---------------------------------

This is the continuation of the thread: http://forums.arcgis.com/threads/15556-ClosedFacility?p=49147#post49147. The scenario is described below:
1) Create a UserControls file by loading the ClosedFacility component from ESRI: http://help.arcgis.com/en/webapi/sil...losestFacility
2) In the usercontrol xaml, I defined
            <esri:Map x:Name="_Map" Background="White" Extent="-117.23,34.03,-117.16,34.08" >
3) Add some code in MainPage.xaml and MainPage.xaml.cs to load the ClosedFacility dialog when it is needed. Also set this component's _Map is set to the same as the parent's map.
Results obtained: All of the buttons are disabled.

I reported this incident. ESRI's Jennifer responded me that:
"All the buttons have Command binding which can only be resolved if their DataContext is resolved. In this sample, each button's DataContext is set to an Editor which is part of Resources. Each of these editors has their Map property bound to a map, using Element binding.
Since you are moving this to a different UserControl that does not contain your map, Element binding will not work. You need to resort to other means of binding. Maybe create your own DependencyProperty (Map) in the UserControl so that you can use this instead. "

Per her advise, I revised the code (only 1 line here) in the usercontrol's xaml:
                <esri:Editor x:Key="MyBarriersEditor" LayerIDs="MyBarriersGraphicsLayer"
                         Map="{Binding ElementName=_Map}" />
to:
                <esri:Editor x:Key="MyBarriersEditor" LayerIDs="MyBarriersGraphicsLayer"
                         Map="{Binding ElementName=MainPage.MyMap}" />
But it still does not work. I believe that the binding is not right. It is somehow chanllege for me and I have very limited experience on it. Do you know how to bind the usercontrol's map to the MainPage's map? Thanks.

Re: How to binding mainpage's map?

JenniferNery — Sat, 11 Dec 2021 23:52:31 GMT

<esri:Editor x:Key="MyBarriersEditor" LayerIDs="MyBarriersGraphicsLayer"
Map="{Binding ElementName=_Map}" />

Is _Map an element of this UserControl? If not, that's the reason the element binding failed. If you want to use this type of binding, your UserControl should have had something like
<esri:Map x:Name="_Map" .../>

I suggested to make Map a DependencyProperty in your UserControl so that in your MainPage you can do something like:

<local:ClosestFacilityControl Map="{Binding ElementName=MyMap}" VerticalAlignment="Top" HorizontalAlignment="Center"/>

Your UserControl will need to set Map of each editor a different way. Also, you will not be able to get layers this way (since MyMap does not exist).
facilitiesGraphicsLayer = MyMap.Layers["MyFacilitiesGraphicsLayer"] as GraphicsLayer;

  public Map Map
  {
   get { return GetValue(MapProperty) as Map; }
   set { SetValue(MapProperty, value); }
  }

  public static readonly DependencyProperty MapProperty = DependencyProperty.Register("Map",
     typeof(Map), typeof(ClosestFacilityControl), new PropertyMetadata(OnMapPropertyChanged));

  private static void OnMapPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
  {
   ClosestFacilityControl control = d as ClosestFacilityControl;
   Map newMap = e.NewValue as Map;
   if(control!=null)
   {
    Editor editor = control.LayoutRoot.Resources["MyBarriersEditor"] as Editor;
    if(editor!=null)
     editor.Map = newMap;
    editor = control.LayoutRoot.Resources["MyFacilitiesEditor"] as Editor;
    if(editor!=null)
     editor.Map = newMap;
    editor = control.LayoutRoot.Resources["MyIncidentsEditor"] as Editor;
    if(editor!=null)
     editor.Map = newMap;

    control.facilitiesGraphicsLayer = newMap.Layers["MyFacilitiesGraphicsLayer"] as GraphicsLayer;
    control.IncidentsGraphicsLayer = newMap.Layers["MyIncidentsGraphicsLayer"] as GraphicsLayer;
    control.barriersGraphicsLayer = newMap.Layers["MyBarriersGraphicsLayer"] as GraphicsLayer;
    control.routeGraphicsLayer = newMap.Layers["MyRoutesGraphicsLayer"] as GraphicsLayer;
   }
  }

Also, you need not create a new thread if it's the same issue 😛

Re: How to binding mainpage's map?

ShaningYu — Thu, 28 Oct 2010 12:56:07 GMT

Jennifer:
Thanks for your response. Per your advise, I am trying to fix the problem step by step.
First of all, in the MainPage, the code was revised as:
            <local:ClosetFacilityControl x:Name="MyClosedFacility" Visibility="Collapsed"
                             Height="240" Width="440" Canvas.Left="306" Canvas.Top="140"
                             DataContext="{Binding ElementName=MyMap}"
                             _Map="{Binding ElementName=MyMap}" />
However, I received the error that:
   the property '_Map' does not exist on the type 'ClosetFacilityControl' in the XML neamspace ...
Actually, in my ClosetFacilityContro.xaml, the '_Map' is defined like that:
<Grid x:Name="LocalPanel" Style="{StaticResource DialogBaseItemsGrid}">
   <esri:Map x:Name="_Map" Background="White" Extent="-117.23,34.03,-117.16,34.08" >
      ....
   </esri:Map>

Please point out what is wrong about my coding. Many thanks.

Re: How to binding mainpage's map?

DominiqueBroux — Sat, 11 Dec 2021 23:52:33 GMT

You have to create a dependency property by code.

You can use the code that Jennifer gave:

 
 public Map Map
{
get { return GetValue(MapProperty) as Map; }
set { SetValue(MapProperty, value); }
}
 
public static readonly DependencyProperty MapProperty = DependencyProperty.Register("Map",
  typeof(Map), typeof(ClosestFacilityControl), new PropertyMetadata(OnMapPropertyChanged));
.......

With your xaml code:

<esri:Map x:Name="_Map" Background="White" Extent="-117.23,34.03,-117.16,34.08" >
....
</esri:Map>

you are creating a new map but not a property which can be set to a map.

Re: How to binding mainpage's map?

ShaningYu — Thu, 28 Oct 2010 14:11:24 GMT

In the Usercontrol's xaml, several GraphicsLayers are defined in the map, like that:
            <esri:Map x:Name="_Map" Background="White" Extent="-117.23,34.03,-117.16,34.08"     >
                

                <esri:GraphicsLayer ID="MyRoutesGraphicsLayer" Renderer="{StaticResource RouteRenderer}" >
                    <esri:GraphicsLayer.MapTip>
                        <Border CornerRadius="10" Background="#DDFFEEEE" BorderThickness="5" BorderBrush="#7700FF00">
                            <StackPanel Orientation="Vertical" HorizontalAlignment="Center" Margin="10">
                                <StackPanel Orientation="Horizontal">
                                    <TextBlock Text="From Incident " FontWeight="Bold" Foreground="#FF0F274E" FontSize="10" VerticalAlignment="Center"/>
                                    <TextBlock Text="{Binding [IncidentID]}" HorizontalAlignment="Left" VerticalAlignment="Center" />
                                </StackPanel>
                                <StackPanel Orientation="Horizontal">
                                    <TextBlock Text="To Facility " FontWeight="Bold" Foreground="#FF0F274E" FontSize="10" VerticalAlignment="Center"/>
                                    <TextBlock Text="{Binding [FacilityID]}" HorizontalAlignment="Left" VerticalAlignment="Center" />
                                </StackPanel>
                                <StackPanel Orientation="Horizontal">
                                    <TextBlock Text="Total Time (mins): " FontWeight="Bold" Foreground="#FF0F274E" FontSize="10" VerticalAlignment="Center" />
                                    <TextBlock Text="{Binding [Total_Time], StringFormat=\{0:F\}}" HorizontalAlignment="Left" VerticalAlignment="Center" />
                                </StackPanel>
                            </StackPanel>
                        </Border>
                    </esri:GraphicsLayer.MapTip>
                </esri:GraphicsLayer>

                <esri:GraphicsLayer ID="MyIncidentsGraphicsLayer" />
                <esri:GraphicsLayer ID="MyBarriersGraphicsLayer" />
                <esri:GraphicsLayer ID="MyFacilitiesGraphicsLayer" />
            </esri:Map>
Per your post, I should remove this piece of code and then use
public Map Map {
   ...
}
Is it right? If so, how can I define these graphicslayers? Thanks.

Re: How to binding mainpage's map?

DominiqueBroux — Sat, 11 Dec 2021 23:52:36 GMT

Per your post, I should remove this piece of code and then use
public Map Map {
...
}
Is it right? If so, how can I define these graphicslayers? Thanks.

No, sorry I was not clear enough. You can keep the definition of your map and its layer in XAML but you have to bind the map property of your control to this map defined in XAML.

 
<local:ClosestFacilityControl x:Name="MyClosedFacility" Visibility="Collapsed"
Height="240" Width="440" Canvas.Left="306" Canvas.Top="140"
Map="{Binding ElementName=_Map}" />

'Map' being the name of your dependency property defined by code
and '_Map' the name of your map defined in XAML

Re: How to binding mainpage's map?

ShaningYu — Thu, 28 Oct 2010 16:19:56 GMT

Thanks for your clarification. I loaded the code
public Map Map {
...
}
into my usercontrol class: ClosestFacilityControl.
but received another error for the 'ClosestFacilityControl', which is the same as my usercontrol's name. The error message shows that
The type or namespace name 'ClosestFacilityControl' could not be found. (are you missing a using directive or an assembly reference?)
Whatdoes it mean? Thanks.

Re: How to binding mainpage's map?

JenniferNery — Fri, 29 Oct 2010 01:42:52 GMT

Did you add the namespace in xaml?

xmlns:local="clr-namespace:YourUserControlNamespace">

and added UserControl this way?

<local:ClosestFacilityControl ../>

Re: How to binding mainpage's map?

ShaningYu — Fri, 29 Oct 2010 13:07:05 GMT

Tat problem was solved but the buttons are still grayed out. I put a stop point at
public Map Map { }
and then run debugging. However, this method is not called at all. I believe there should be a call somewhere that I haven't specify. Please tell me how to call the method. Many thanks.

Re: How to binding mainpage's map?

JenniferNery — Sun, 12 Dec 2021 16:37:17 GMT

If you have properly defined the DependencyProperty in your ClosestFacilityControl, and have set Map property when you instantiated an instance of this control in your MainPage, you can set breakpoint at OnMapPropertyChanged and it should be hit.

Also in your ClosestFacilityControl, did you remove the element binding to map for the editors?

 
       <esri:Editor x:Key="MyBarriersEditor" LayerIDs="MyBarriersGraphicsLayer" Map="{Binding ElementName=MyMap}" />

This should be removed since the OnMapPropertyChanged will handle setting the editor's Map property.

Re: How to binding mainpage's map?

ShaningYu — Fri, 29 Oct 2010 16:19:35 GMT

After the removal of
Map="{Binding ElementName=MyMap}
The problem is still unsolved.

Re: How to binding mainpage's map?

JenniferNery — Fri, 29 Oct 2010 17:18:06 GMT

Kindly see the attached sample. Maybe you can compare what you have done different and then maybe see why this sample works.

Re: How to binding mainpage's map?

ShaningYu — Fri, 29 Oct 2010 17:23:16 GMT

One of the problem is I am still not sure how to effectively bind to the MainPage's map. I will try your sample code next week.
Thanks and have a nice weekend.

Re: How to binding mainpage's map?

ShaningYu — Tue, 02 Nov 2010 13:37:33 GMT

Jennifer:
I tried your code that is essentially the same as the source code in http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#ClosestFacility
But the results received are identially - All of the buttons except for the 'Clear All Graphics' are disabled. I might give up to use if for the time-being.
Thanks for your a lot of time.
Shaning

Re: How to binding mainpage's map?

JenniferNery — Tue, 02 Nov 2010 13:58:23 GMT

I checked the attached solution and it works for me, the buttons are not disabled. The code is identical from the SDK sample because that is what you were trying to follow, right? The only difference is they reside in different UserControls but the Map DependencyProperty should work.

Re: How to binding mainpage's map?

XavierBerni — Sun, 28 Nov 2010 15:26:45 GMT

I am investigating a similar problem where the Map DependencyProperty isn't getting set from my UserControl which exists in my custom Silverlight library. Seems like this could be related to Silverlight versions. The following information comes from the msdn link http://msdn.microsoft.com/en-us/library/cc221408(VS.95).aspx.

"Applications targeting Silverlight version 3 can only bind to target properties of a FrameworkElement. Support for binding to any DependencyObject dependency property was added in Silverlight 4."

It does not look like UserControl derives from FrameworkElement. See msdn documentation:

http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement(v=VS.95).aspx#inheritanceContinued

The following link shows someone with a similar problem and the workaround they used.

http://betaforums.silverlight.net/forums/p/182820/418564.aspx

Re: How to binding mainpage's map?

DominiqueBroux — Mon, 29 Nov 2010 08:33:25 GMT

"Applications targeting Silverlight version 3 can only bind to target properties of a FrameworkElement. Support for binding to any DependencyObject dependency property was added in Silverlight 4."
It does not look like UserControl derives from FrameworkElement. See msdn documentation:
http://msdn.microsoft.com/en-us/libr...tanceContinued

UserControl derives from Control, so derives indirectly from FrameworkElement as well.

The following link shows someone with a similar problem and the workaround they used.

http://betaforums.silverlight.net/fo...20/418564.aspx

I am not sure we are in the same case since Map doesn't derive from ContentControl.
Personally I never experienced any issue when adding a DP of type Map but if you run into this kind of issue please share the code I will try to analyze.