Unplanned
Last Updated: 06 Nov 2020 20:06 by ADMIN
Currently, to make the MultiSelect control work in an EditTemplate of a Grid in Batch EditMode, custom implementation is needed.
Unplanned
Last Updated: 25 May 2020 11:26 by ADMIN

A "Control 'RadMultiSelect1' referenced by the ControlToValidate property of 'MultiSelectValidator1' cannot be validated" error is thrown when the RadMultiSelect id is passed to the ControlToValidate property of the RequiredFieldValidator or CustomValidator.

Workaround: Using a CustomValidator with no ControlToValidate

<telerik:RadMultiSelect ID="RadMultiSelect1" runat="server" DataTextField="text" DataValueField="value">
    <Items>
        <telerik:MultiSelectItem Text="Item 1" Value="1"></telerik:MultiSelectItem>
        <telerik:MultiSelectItem Text="Item 2" Value="2"></telerik:MultiSelectItem>
        <telerik:MultiSelectItem Text="Item 3" Value="3"></telerik:MultiSelectItem>
    </Items>
</telerik:RadMultiSelect>

<telerik:RadButton runat="server" ID="RadButton1" Text="Postback" AutoPostBack="true" />

<asp:CustomValidator ErrorMessage="Please select an item" ClientValidationFunction="ClientValidationFunction" runat="server" />
<script>
    function ClientValidationFunction(sender, args) {
        var multiselect = $find("<%= RadMultiSelect1.ClientID %>");

        if (multiselect.get_value().length == 0) {
            args.IsValid = false;
        }
    }
</script>