<div style="display: flex; gap: 2em;">
    <div>
        <TelerikButtonGroup SelectionMode="@ButtonGroupSelectionMode.Single">
            <ButtonGroupToggleButton @bind-Selected="@UseOnChange">Use OnChange</ButtonGroupToggleButton>
            <ButtonGroupToggleButton @bind-Selected="@UseOnClose">Use OnClose</ButtonGroupToggleButton>
        </TelerikButtonGroup>

        <TelerikDropDownList Data="@Data"
                             @bind-Value="@Value"
                             ValueField="@nameof(SampleModel.Text)"
                             OnChange="@OnDropDownListChange"
                             OnClose="@OnDropDownListClose"
                             Width="160px" />

    </div>
    <div>
        <TelerikButton OnClick="@( () => CloseLog = string.Empty )">Clear Event Log</TelerikButton>
        <p>
            <pre>@CloseLog</pre>
        </p>
    </div>
</div>

@code {
    private List<SampleModel> Data { get; set; } = new();

    private string Value { get; set; } = string.Empty;
    private List<string> Values { get; set; } = new();

    private string CloseLog { get; set; } = string.Empty;

    private bool UseOnClose { get; set; } = true;
    private bool UseOnChange { get; set; }

    [CascadingParameter]
    public DialogFactory? TelerikDialogs { get; set; }

    private async Task OnDropDownListChange(object currentValue)
    {
        CloseLog += $"OnChange {DateTime.Now.ToString("HH:mm:ss.fff")} \n";

        if (UseOnChange)
        {
            await TelerikDialogs!.AlertAsync("OnChange");
        }
    }

    private async Task OnDropDownListClose(DropDownListCloseEventArgs args)
    {
        CloseLog += $"OnClose {DateTime.Now.ToString("HH:mm:ss.fff")} \n";

        if (UseOnClose)
        {
            await TelerikDialogs!.AlertAsync("OnClose");
        }
    }

    public class SampleModel
    {
        public int Id { get; set; }
        public string Text { get; set; } = string.Empty;
    }
}