<TelerikWindow @bind-Visible="@WindowIsVisible" Modal="true">
    <WindowTitle>
        <strong>The Title</strong>
    </WindowTitle>
    <WindowContent>
        Selected value: @selectedValue
        <br />

        <TelerikComboBox Data="@myComboData" TextField="MyTextField" ValueField="MyValueField" @bind-Value="selectedValue"
                         Placeholder="Select an item..." ClearButton="true" Filterable="true" FilterOperator="@StringFilterOperator.Contains">
        </TelerikComboBox>
        <p>some more content</p>
        <p>lore ipsum</p>
    </WindowContent>
    <WindowActions>
        <WindowAction Name="Minimize"></WindowAction>
        <WindowAction Name="Maximize"></WindowAction>
        <WindowAction Name="Close"></WindowAction>
    </WindowActions>
</TelerikWindow>

<TelerikButton OnClick="@( () => WindowIsVisible = !WindowIsVisible )">Toggle window</TelerikButton>

@code {
    bool WindowIsVisible { get; set; }
    IEnumerable<MyDdlModel> myComboData = Enumerable.Range(1, 20).Select(x => new MyDdlModel { MyTextField = "item " + x, MyValueField = x });

    int selectedValue { get; set; }

    //in a real case, the model is usually in a separate file
    //the model type and value field type must be provided to the dropdpownlist
    public class MyDdlModel
    {
        public int MyValueField { get; set; }
        public string MyTextField { get; set; }
    }
}

<style>
    .k-animation-container {
        z-index: 15000;
    }
</style>