blazor display validation message

C#
EditContext _editContext = new EditContext(_foodTruck);
private async void HandleValidSubmit()
{
  var messageStore = new ValidationMessageStore(_editContext);
  if (_foodTruck.StartDelivery >= _foodTruck.EndDelivery)
  {
    messageStore.Add(_editContext.Field("EndDelivery"), "Bad time entered");
    _editContext.NotifyValidationStateChanged();
  }
 if (!_editContext.Validate()) return;
}<ValidationMessage For="@(() => starship.MaximumAccommodation)" />
@using System.Globalization
@typeparam TValue
@inherits InputBase<TValue>

<input @attributes="AdditionalAttributes" type="radio" value="@SelectedValue" 
       checked="@(SelectedValue.Equals(Value))" @onchange="OnChange" />

@code {
    [Parameter]
    public TValue SelectedValue { get; set; }

    private void OnChange(ChangeEventArgs args)
    {
        CurrentValueAsString = args.Value.ToString();
    }

    protected override bool TryParseValueFromString(string value, 
        out TValue result, out string errorMessage)
    {
        var success = BindConverter.TryConvertTo<TValue>(
            value, CultureInfo.CurrentCulture, out var parsedValue);
        if (success)
        {
            result = parsedValue;
            errorMessage = null;

            return true;
        }
        else
        {
            result = default;
            errorMessage = $"{FieldIdentifier.FieldName} field isn't valid.";

            return false;
        }
    }
}
@page "/RadioButtonExample"
@using System.ComponentModel.DataAnnotations

<h1>Radio Button Group Test</h1>

<EditForm Model="model" OnValidSubmit="HandleValidSubmit">
    <DataAnnotationsValidator />
    <ValidationSummary />

    @for (int i = 1; i <= 5; i++)
    {
        <label>
            <InputRadio name="rate" SelectedValue="i" @bind-Value="model.Rating" />
            @i
        </label>
    }

    <button type="submit">Submit</button>
</EditForm>

<p>You chose: @model.Rating</p>

@code {
    private Model model = new Model();

    private void HandleValidSubmit()
    {
        Console.WriteLine("valid");
    }

    public class Model
    {
        [Range(1, 5)]
        public int Rating { get; set; }
    }
}

Source

Also in C#: