Question

My scenario:
I’ve got a Silverlight Application with a View, where i want to bind the textboxes to an object (two-way) and all labels to a dictionary holding the label translations.

My approach was to set the datacontext of the page to a dictionary with two items, one of them is the object and the other is the translation-dictionary.

In xaml the code looks like the following:

<TextBlock Text="{Binding [dict].[name],FallbackValue='Fallback'}" />
<TextBox Text="{Binding [obj].name,Mode=TwoWay}" />

This works initially, if I however change the object on the datacontext, the xaml is not notified about any changes and doesn’t update.

I’ve had a working solution using a Converter for the translations, however due to the limitations on one converterparameter I didn’t like the solution. In addition it wasn’t possible to place a fallback-value in the textblock, which resulted in “invisible” textblocks while designing the page.

Any suggestions on how to solve this issue? It doesn’t have to be using my dictionary, it would be also okay if i could set the datacontext to the object (which works) and bind the labels somehow different.

Answer 1

I found a solution, but wasn’t able to answer my own question (8h limit..)
I think this is just the approach Hydroslide suggested.

---

1. Create a class which holds all data and implements INotifyPropertyChanged

   Public Class MyDatacontext
     Implements ComponentModel.INotifyPropertyChanged
   
   'Properties
   Private _obj As Object
   Private _dict As Dictionary(Of String, String)
   
   'Events
   Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
   
   'Methods
   Public Property Obj As Object
     Get
       Return _obj
     End Get
     Set(ByVal value As Object)
       _obj = value
       'Notify the xaml about the changed Object
       RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("Obj"))
     End Set
   End Property
   
   Public Property Dict As Dictionary(Of String, String)
     Get
       Return _dict
     End Get
     Set(ByVal value As Dictionary(Of String, String))
       _dict = value
       'Notify the xaml about the changed translation
       RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("Dict"))
     End Set
   End Property
   End Class
   

2. Define a private var in your page code

   Private mycontext As New MyDatacontext
   

3. In the constructor of your page, fill your “mycontext” with the desired data

   mycontext.Dict = LoadDictionary()
   mycontext.Obj = LoadObject()
   Me.DataContext = mycontext
   

4. Change your xaml to the following

   <TextBlock Text="{Binding Dict.[name],FallbackValue=MyFallback}" />
   <TextBox Text="{Binding Obj.name,Mode=TwoWay}" />
   

5. Update your object/dictionary as you like using

   mycontext.Obj = LoadNextObject()