radzen-blazor/Radzen.Blazor/RadzenNotification.razor

@implements IDisposable
@using System.Collections.Specialized

<div aria-live="polite" class="rz-notification" style="@Style">
@if (Service?.Messages != null)
{
    @for (var i = 0; i < Service.Messages.Count; i++)
    {
        <div @key="Service.Messages[i]">
            @DrawMessage(i, Service.Messages[i])
        </div>
    }
}
</div>
@code {
    [Inject] private NotificationService? Service { get; set; }

    [Parameter]
    public string? Style { get; set; }

    RenderFragment DrawMessage(int index, NotificationMessage m)
    {
        return new RenderFragment(builder =>
        {
            var i = 0;
            builder.OpenComponent(i, typeof(RadzenNotificationMessage));
            builder.AddAttribute(i++, "Message", m);
            builder.AddAttribute(i++, "Style", m.Style);
            builder.CloseComponent();
        });
    }

    void Update(object? sender, NotifyCollectionChangedEventArgs args)
    {
        InvokeAsync(StateHasChanged);
    }

    public void Dispose()
    {
        if (Service?.Messages != null)
        {
            Service.Messages.CollectionChanged -= Update;
        }
    }

    protected override void OnInitialized()
    {
        if (Service?.Messages != null)
        {
            Service.Messages.CollectionChanged += Update;
        }
    }
}