WPF ListBox + Binding + IDataErrorInfo =?

Question

I have a WPF MVVM application. In the View I have a multiselect ListBox. In the ViewModel I have a property for the selected items in the List.

Using a technique similar to the one in the answer to this question I can bind my property to the ListBox.

But I also want to do data validation via IDataErrorInfo. All I want to do is check that the user has selected at least one item in the list. Adding ValidatesOnDataErrors=True to the binding doesn't work.

Is there any way to have a multiselect listbox that's databound with IDataErrorInfo?

Can you post your code? Define "doesn't work"? Are you getting an error? Is the imlementation of IDataErrorInfo called? — Anderson Imes, Aug 05 '09 at 07:10

score 0 · Answer 1 · answered Dec 12 '14 at 14:19

0

If you're using a behavior for binding ViewModel's List with ListBox's selected items, manually update the binding after add/remove item(s):

var binding = BindingOperations.GetBindingExpression(this, SelectedItemsListBoxBehavior.SelectedItemsProperty);
if (binding != null)binding.UpdateSource();

answered Dec 12 '14 at 14:19

Fanch

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binding.ValidateWhithoutUpdate() is available but doesn't seem to do the job. – Fanch Dec 12 '14 at 14:23

score -1 · Answer 2 · answered Jun 25 '11 at 18:53

-1

Even it is multiselect ListBox you can bind SelectedItem

 SelectedItem="{Binding FakeSelectedItem, ValidatesOnDataErrors=True}"

and then do a validation when this property changes.

PS
For the binding I am using this solution MVVM Multiselect Listbox

answered Jun 25 '11 at 18:53

Robert Vuković

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WPF ListBox + Binding + IDataErrorInfo =?

2 Answers2