Resolved How to use RadzenRequiredValidator to validate a RadzenDropDown?

[RajeshKumar]

I have one ParentComponent and one ChildComponent. The ChildComponent contain RadzenDropDown is not validating when click on submit button from ParentComponent .
ParentComponent.razor:

<RadzenTemplateForm TItem="ProductModel" Submit="OnValidSubmit" Data=@model>
 <DataAnnotationsValidator />
   <ChildComponent @ref="productSelection" />
  </RadzenTemplateForm> 

@code{
    private async void OnValidSubmit()
    {
        if (productSelection.idCategory?.Any() == true)
        {
            //save the checked items.
        }
        else
        {
            //show validation message.
        }
    }
}

ChildComponent.razor:

<RadzenDropDown class="form-control" placeholder="Select Category"
                        AllowClear="true"
                        AllowFiltering="true"
                        Multiple="true"
                        FilterCaseSensitivity="FilterCaseSensitivity.CaseInsensitive"
                        TextProperty="Name"
                        ValueProperty="Id"
                    @bind-Value=@idCategory
                    Data = @_listCategory
                    Name="CategoryName"
                        Change=@(args => onProductsChange(args)) />
                    <RadzenRequiredValidator style="color:red; font-weight:bold;position: absolute;" Component="CategoryName" Text="Category is Required" />
    @code{
    public IEnumerable<string> idCategory{ get; set; } = new List<string>();

    IList<string> _listCategory;
}

I have tried to implementing certain properties such as ValueExpression and FieldIdentifier from here and here But I am not getting.

 

[Skydiver]

This isn't a C# general discussion topic. Moving to a more appropriate forum...