ListBox multiple item selection
Currently in DotVVM there is no support for native HTML input <select multiple>...</select>
We do have <dot:ListBox> control but it does not support multiple selected items.
ASP.NET Web Forms has <ListBox SelectionMode="Multiple"> that can be used in this case.
I implemented SelectionMode property for our <dot:ListBox>.
Sorry, I found out we already have MultiSelect component. It's most likely somehow broken, but I'd prefer to have the functionality as a separate component instead of switching the behavior with the SelectionMode property. It's value influences the expected type of other properties, I'd like to like to avoid that. Would you mind to transfer your code to the MultiSelect component?
We should reuse some parts of this implementation (ValidateUsage and tests for example).
Merged via #1521