How can I get NotifyCollectionChangedEventHandler to work on the Values of a SortedList in WPF binding

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I've got the following two combo boxes. One updates the content when the SortedList changes and the other doesn't.

XML

<ComboBox Name="cbxNotUpdating"
  ItemsSource="{Binding Path=DataContext.Versions.Values, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}"
  SelectedValue="{Binding Path=Version, Mode=TwoWay}">
</ComboBox>

<ComboBox Name="cbxUpdating"
  ItemsSource="{Binding Path=DataContext.Versions, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}"
    SelectedValue="{Binding Path=Version, Mode=TwoWay}">
</ComboBox>

The obvious difference is that cbxNotUpdating binds to the Values and cbxUpdating binds to the SortedList itself.
My List implementation looks like this:

C#

public class VersionList : SortedList<string, Version>, INotifyCollectionChanged
{
...
  public event NotifyCollectionChangedEventHandler CollectionChanged;
  protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
  {
      if (CollectionChanged != null)
      {
          CollectionChanged(this, e);
      }
  }
}

How can I make the cbxNotUpdating update?
I've got a property that is a 'Version' that I want to have as the SelectedValue at the same time I have a template that works on just the Value part of the collection.

I'm using vs2010.

Posted 20-Jan-12 5:01am

Erik Rude

Updated 20-Jan-12 6:15am

v2

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Comments

SteveAdey 20-Jan-12 11:29am

The difference is that the Values are just an IList<tvalue> which has no mechanism to notify of its changes.

What are you trying to achieve with cbxNotUpdating that you cannot with cbxUpdating?

Erik Rude 20-Jan-12 12:17pm

Thanks fo rthe reply - I've got a property that is a 'Version' that I want to have as the SelectedValue at the same time (this doesn't work in the cbxUpdating) I have a template that works on just the Value part of the collection. I refer to that just on the DataType eg:
<datatemplate x:key="VersionTemplate" datatype="{x:Type MyApp:Version}" xmlns:x="#unknown">

Erik Rude 20-Jan-12 12:21pm

I will try to work around this then. I just thought that the Values would automatically refresh when the collection did.

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Erik Rude · Accepted Answer · 2012-01-22T22:01:00

Thanks to SteveAdey for pointing out the fatal flaw.
In the end I bound to the SortedList changed the SelectedValuePath and used a DataTemplate binding to the Value to get to my desired goal.
My solution looks like this:

XML

<ComboBox Name="cbxFolder" Grid.Column="1" Grid.Row="0"
                ItemsSource="{Binding Path=DataContext.Versions, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}"
                SelectedValue="{Binding Path=Version, Mode=TwoWay}"
                SelectedValuePath="Value"
                ComboBox.ItemTemplate="{StaticResource VersionCbxTemplate}">
</ComboBox>

With this DataTemplate in the resources

XML

<DataTemplate x:Key="saturnVersioncbx">
  <StackPanel Margin="5" DataContext="{Binding Value}" >...
  </StackPanel>
</DataTemplate>