Clear bind-Value does not clear the multiselect

[Fredrik]

When clearing the bind-Value the multiselect still has the values previously selected.

Is there another way to clear the multiselect?

[Joana]

Hi Fredrik,

The Value of the MultiSelect component is of type List<TValue>. However, any manipulations applied to the list do not trigger the Blazor lifecycle for update of the parameter as the reference of the list remains unchanged (for example: .Clear(), .Add()). That being said, you need to reinitialize the list of values in order to make sure that the Multiselect will be updated accordingly:

<div>
        <button @onclick="@OnClick">Clear MultiSelect Values</button>
        <TelerikMultiSelect Data="@Sports"
                            @bind-Value="@Values"
                            Placeholder="Select sports"
                            Width="350px" />
    <div>
        Selected Sports:
        <strong>
            @string.Join(", ", Values)
        </strong>
    </div>
</div>

@code {
    List<string> Sports = new List<string>() {
        "Baseball",
        "Basketball",
        "Cricket",
        "Field Hockey",
        "Football",
        "Table Tennis",
        "Tennis",
        "Volleyball"
    };
    List<string> Values = new List<string>();

    private void OnClick()
    {
        Values.Clear();
    }
}

We understand that the type of the value is restrictive, and we have a logged feature request to update its type:

https://feedback.telerik.com/blazor/1478998-change-telerikmultiselect-value-to-type-icollection-t-or-ilist-t 

Once we support binding to ObservableCollection of values, you will be able to update the set of values through it.

Let me know if you have further questions.

Regards,
Joana
Progress Telerik