Hello, it's about wpf. Thanks

By the selection appears correct in the UI, are you referring to the text box portion of the combo after you update the selected items programatically.  Also what is the relevant code that you are using to update the selection?

Yes, I mean text box portion gets updated but not the checkboxes.

I update it like this :

public ObservableCollection<object> Types
        {
            get { return _types; }
            set
            {
                _types = new ObservableCollection<object>(value);
                _types.CollectionChanged +=TypesOnCollectionChanged;
                OnPropertyChanged();
            }
        }
        
private void TypesOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.Action == NotifyCollectionChangedAction.Add)
            {  
                            Types = new ObservableCollection<object>(_defaultType);
            }
			OnPropertyChanged(nameof(Types));
        }

The code provided doesn't really show how you are changing the selection of the XamComboEditor unless you are binding the selection to the Types property and if so it would be good to see that binding.

Note that I am not sure why you would change the instance of the collection when items are added to the observable collection, or is that meant to clear an existing selection if that collection is representing a collection of selected items?  Also my expectation is that this code will result in a memory leak as the CollectionChanged event is never unhooked when the instance of the collection is changed.

Please provide more of the code including how your are using the XamComboEditor so it is clearer what is being done in your application.

Ok here's my use case. I have a list of types = {type1, type2, type3, Any}

and when the user checks the type "Any", I want to uncheck all the other types

here's my code :

<ig:XamComboEditor 
                                                   MaxWidth="150"
                                                   AllowMultipleSelection="True"
                                                   CheckBoxVisibility="Visible"
                                                   ItemsSource="{Biding  Path=AllTypes}"
                                                   SelectedItems="{Binding Path=Types, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,NotifyOnSourceUpdated=True,NotifyOnTargetUpdated=True}"
                                                   DisplayMemberPath="Label" >
                                </ig:XamComboEditor>

public ObservableCollection<object> Types
        {
            get { return _types; }
            set
            {
                _types = new ObservableCollection<object>(value);
                _types.CollectionChanged +=TypesOnCollectionChanged;
                OnPropertyChanged();
            }
        }
        
private void TypesOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            var defaultType = AllTypes.SingleOrDefault(dt => dt.Name.Equals("Any"));
            if (e.Action == NotifyCollectionChangedAction.Add)
            {  
                    var newtype = e.NewItems.Cast<MyType>().SingleOrDefault(dt => dt.Equals(defaultType));
                        if (defaultType != null && Types.Count > 1)
                        {
                            Types = new ObservableCollection<object>(defaultType);
                        }
            }
			OnPropertyChanged(nameof(Types));
		}