WPF ListView ignores SelectedItem-change

Question

I am working with a ListView in WPF which is bound an observable collection. I then bound the SelectedItem-Property to a property of the ViewModel.

When I select an item in the ListView via GUI "SelectedItem" is changed.
When I change "SelectedItem" in the ViewModel, the ListView only changes, when I set the SelectedItem to NULL.
When I set any other (valid!) object (like the first entry of the ObservableCollection) the ListView just ignores it.

Furthermore: When I want to "Veto" a SelectedItem Change (because data is not saved), the ListView highlights the new selected item instead of the SelectedItem-Property of the ViewModel.

I already tried to change the Binding to Mode=TwoWay - doesn't work as well (otherwise the "NULL" change to SelectedItem wouldn't work as well)

This is the code from the view:

<ListView ItemsSource="{Binding Configurations}" SelectedItem="{Binding SelectedUserConfiguration}" SelectionMode="Single">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="User Configuration" DisplayMemberBinding="{Binding ConfigurationName}" Width="200" />
        </GridView>
    </ListView.View>
</ListView>

And my ViewModel:

public ObservableCollection<UserConfigurationViewModel> Configurations { get; private set; }
private UserConfigurationViewModel _selectedUserConfiguration;
public UserConfigurationViewModel SelectedUserConfiguration
{
  get { 
    return this._selectedUserConfiguration; 
  }
  set
  {
      if (this._selectedUserConfiguration != null && this._selectedUserConfiguration.WasChanged)
      {
        if (ask-user)
        {
          this._selectedUserConfiguration.Reset();
          this._selectedUserConfiguration = value;
        }
      }
      else
      {
        this._selectedUserConfiguration = value;
      }
      NotifyOfPropertyChange(() => this.SelectedUserConfiguration);
    }
  }

I'm just guessing, could the problem be that the SelectedItem property of the ListView is of type object and your SelectedUserConfiguration property is of type UserConfigurationViewModel? — Dante

Sheridan Sheridan · Accepted Answer · 2013-10-02T15:49:12

In order to select the selected item in any collection control from code, the selected item must be an actual item from the collection that is bound to the ItemsSource property. This can be achieved easily enough with LinQ if your collection items have at least one unique property:

SelectedUserConfiguration = Configurations.Where(c => c.UniqueProperty == 
    valueOfItemToSelect).FirstOrDefault();

If your data type objects do not have a unique property, you can simply add an int Id property for this purpose.

WPF ListView ignores SelectedItem-change

2 Answers