Question

I have some ObservableCollections binded to some WPF controls and they work fine. And I have a feature where I completely replace these ObservableCollections through reassignment and filling them again, but after doing this, the WPF controls don’t get updated.

Or is this binding connection only established at startup once, and then I should never reinitialize the ObservableCollections, but only change them?

EDIT:

public partial class MainWindow : Window
{
    ObservableCollection<EffectViewModel> effects;
    public ObservableCollection<EffectViewModel> Effects
    {
        get { return this.effects; }
        set
        {
            this.effects = value;
            this.RaisePropertyChanged ( "Effects" );
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    void RaisePropertyChanged ( string name )
    {
        var handler = this.PropertyChanged;
        if ( handler != null )
            handler ( this, new PropertyChangedEventArgs ( name ) );
    }
}

public void LoadEffects ( string path, string filename )
{
    //returns new ObservableCollection<EffectViewModel> ( );
    this.Effects = File.Load ( path, filename );
}

public class EffectViewModel
{
    public bool this [ EffectType type ]
    {
        get { return AllEffects.First ( e => e.Type == this.Type ).IsSupported; }
        set
        {
            AllEffects.First ( e => e.Type == this.Type ).IsSupported = value;
            this.RaisePropertyChanged ( "this" );
        }
    }

    #region Events

    public event PropertyChangedEventHandler PropertyChanged;
    void RaisePropertyChanged ( string name )
    {
        var handler = this.PropertyChanged;
        if ( handler != null )
            handler ( this, new PropertyChangedEventArgs ( name ) );
    }

    #endregion
}

EDIT2:

<Window x:Class="EffectWindow.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        DataContext="{Binding RelativeSource={RelativeSource Self}}"
        Title="Effect Display" Height="200" Width="700"
    <DockPanel VerticalAlignment="Stretch">

        <ListView
            ItemsSource="{Binding Effects}"
            AlternationCount="2"
            DockPanel.Dock="Top"
            HorizontalContentAlignment="Stretch">

            <ListView.View>
                <GridView>

                    <GridViewColumn
                        Width="70"
                        Header="GPU">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <CheckBox
                                    Margin="0"
                                    HorizontalAlignment="Center"
                                    IsChecked="{Binding [GPU], Mode=TwoWay}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>

                    <GridViewColumn
                        Width="70"
                        Header="CPU">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <CheckBox
                                    Margin="0"
                                    HorizontalAlignment="Center"
                                    IsChecked="{Binding [CPU], Mode=TwoWay}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>

                </GridView>
            </ListView.View>
        </ListView>

    </DockPanel>
</Window>

Answer 1

The object you are binding to should implement the INotifyPropertyChanged interface. Then, the bound collection property should raise PropertyChanged event in its setter. Something like this:

public ObservableCollection<MyObject> MyCollection
{
   get
   {
      return _myCollection;
   }
   set
   {
      _myCollection = value;
      RaisePropertyChanged("MyCollection");
   }
}