Multilookup control with items selection based on criteria

Jun 11, 2015 at 9:47 AM
I have a multilookup control where there are 10 items (for example). Now if item A is selected then user should not be able to select item B and vice a versa.

That means item A and item B cannot be in selected list at same time. Either A or B should be in the select list.

Is there any default way provided to have such functionality? or in case there is better approach to have this facility then it would be really helpful for me.

Jun 11, 2015 at 10:11 AM
think you need to write a custom validation attribute for this
Jun 11, 2015 at 10:21 AM
Ok thanks,

Is there any sample code for custom validation which will guide me to have such functionality on multilookup control?
Jun 11, 2015 at 10:27 AM
Edited Jun 11, 2015 at 10:32 AM
the attribute would be for an int[] array, not specific to multilookup, it is applied on the ViewModel Property
ProDinner uses one to validate max meals per dinner