Question

I’m a newbie to Visual Studio (2010) and Expression Studio (4).

I have been trying to get a TreeView to connect to a .mdb database that I have connected in Visual Studio (using Silverlight Business Application) to show a Navigation Tree for the Name Properties in each table. I have 2 levels of hierarchy:

(there are many more properties than shown but these are the only required)

1. Root Level: Location Table [LocationName Property]
2. First Level: Area Table [AreaName Property] [LocationID]
3. Second Level: Inspection Table [InspectionName Property] [AreaID]

I have tried many ways to connect and none seem to work – I am quite happy now with making a TreeView template with a connection to hierarchical Sample Data created in Expression Blend. Unfortunately, I can only seem to make a connection with the top level of my real database – so it only shows the names of the locations and won’t expand any further.

I have no idea what to do. The code I’m using is: (no code-behind)

Home.xaml

 <riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my1:Location, CreateList=true}" Height="0" LoadedData="locationDomainDataSource_LoadedData_1" Name="locationDomainDataSource" QueryName="GetLocationsQuery" Width="0">
     <riaControls:DomainDataSource.DomainContext>
          <my:InspectDomainContext />
     </riaControls:DomainDataSource.DomainContext>
 </riaControls:DomainDataSource>

 <sdk:TreeView Height="200" ItemsSource="{Binding ElementName=locationDomainDataSource, Path=Data}" Name="locationTreeView1" Width="200" >
      <sdk:TreeView.Resources>
           <ResourceDictionary>
                <ResourceDictionary.MergedDictionaries>
                     <ResourceDictionary Source="NavigationTreeResourceDictionary.xaml"/>
                </ResourceDictionary.MergedDictionaries>
            </ResourceDictionary>
       </sdk:TreeView.Resources>
       <sdk:TreeView.ItemTemplate>
            <StaticResource ResourceKey="RootLevel"/>
       </sdk:TreeView.ItemTemplate>
   </sdk:TreeView>

Navigation Tree Resource Dictionary

 <common:HierarchicalDataTemplate x:Key="Level2">
     <StackPanel Orientation="Horizontal">
         <TextBlock Margin="5,0,3,0" 
               FontStyle="Italic" 
               Text="{Binding Path=Name}" />                    

     </StackPanel>
 </common:HierarchicalDataTemplate>

 <common:HierarchicalDataTemplate x:Key="Level1"                 
    ItemsSource="{Binding Path=Inspections}"
    ItemTemplate="{StaticResource Level2}">
     <StackPanel Orientation="Horizontal">
         <TextBlock Margin="5,0,3,0" 
               Text="{Binding Path=Name}" />

     </StackPanel>
 </common:HierarchicalDataTemplate> 

 <common:HierarchicalDataTemplate x:Key="RootLevel"
     ItemsSource="{Binding Path=Areas}"
     ItemTemplate="{StaticResource Level1}">
     <StackPanel Orientation="Horizontal">
         <TextBlock Margin="5,0,3,0"
               Text="{Binding Path=Name}" 
               FontWeight="Bold" FontSize="12" />
     </StackPanel>
 </common:HierarchicalDataTemplate>

Domain Service (c#) GetLocationsQuery

 public IQueryable<Location> GetLocations()
    {
        return this.ObjectContext.Locations.OrderBy(l=>l.Name);
    }

Is it perhaps something to do with the Query used? Should I be putting the information I need for the treeview in the GetLocationsQuery?

• If so how do I put in the query to return a list of location names, child area names and child inspection names?

Thank you in advance.

Answer 1

Have found a solution, I will post for others in the case it is needed:

It was the domain service and metadata info that needed to be changed =>

In the metadata file, each EntityCollection in a table that you want the service to pass back needs [Include] e.g.:

Locations Table

[Include]
public EntityCollection<Area> Areas { get; set; }

Areas Table

[Include]
public EntityCollection<Inspection> Inspections { get; set; }

Inspections Table

[Include]
public EntityCollection<InspectionItem> InspectionItems { get; set; }

and in the domain service file the query used requires:

public IQueryable<Location> GetLocationsAndSubCategories()
    {
        return this.ObjectContext.Locations.Include("Areas.Inspections");
    }

where each “.Entity” is the name of the collection entities that have been included in the metadata file.

Back to the xaml – it should work with the code as long as the Binding path names are the same as the EntityCollection Names.

🙂 Hope that has been useful