Undoing Selection Change in MVVM

[Masoud]

Hi,

I have a RadCombo in a view that in bound to a ViewModel.  SelectedValue of RadCombo is bound to a property Selected with a backing field. Under certain circumstances I need to "reject" user changes to the selection.  In order to achieve this I did the following

private TL _selected;

 

public TL Selected

{

    get { return _selected; }

    set

    {

        if (<some condition -> don't change selection>)

        {

            RaisePropertyChanged("Selected");

            return;

        }

        _selected = value;

        RaisePropertyChanged("Selected");

    }

}

However the RadCombo still shows the "rejected" value instead.

I am running Version 2011.3.1116.1040.

Thank you for your help!

[Valeri Hristov]

Hi Klaus,

As far as I know, while a dependency property is changing, it does not listen to INotifyPropertyChanged notifications. The standard WPF ComboBox control behaves in the same way. To workaround this you should call OnPropertyChanged through a dispatcher. You can find attached a sample application that demonstrates how.

Regards,
Valeri Hristov
the Telerik team

[Masoud]

Hi Valeri,

thank you for your reply!

I have implementied your solution and it works fine!

Regards