#@item.ToString("N0") Item number @item of one million

``` ```csharp private BitVirtualize basicRef = default!; private readonly int[] basicItems = Enumerable.Range(0, 1_000_000).ToArray(); private int basicTargetIndex; private int basicVisibleStart; private int basicVisibleEnd; private async Task ScrollToBasicIndex() { await basicRef.ScrollToIndexAsync(basicTargetIndex, BitVirtualizeScrollAlignment.Start, smooth: true); } private void OnBasicRangeChanged((int Start, int End) range) { (basicVisibleStart, basicVisibleEnd) = range; StateHasChanged(); } ``` \n**ItemsProvider**: ```razor

@product.Name record #@product.Id.ToString("N0") · loaded at @product.LoadedAt

``` ```csharp private const int TotalProducts = 100_000; private async ValueTask> LoadProducts(BitVirtualizeItemsProviderRequest request) { await Task.Delay(500, request.CancellationToken); // simulate a network fetch var items = Enumerable.Range(request.StartIndex, Math.Min(request.Count, TotalProducts - request.StartIndex)) .Select(i => new Product(i, $"Product {i:N0}", DateTime.Now.ToString("HH:mm:ss"))) .ToList(); return new(items, TotalProducts); } public record Product(int Id, string Name, string LoadedAt); ``` \n**Dynamic size**: ```razor

@post.Author · @post.Time

@post.Body

``` ```csharp private List posts = []; protected override void OnInitialized() { var random = new Random(42); var words = "lorem ipsum dolor sit amet consectetur adipiscing elit sed do eiusmod tempor incididunt ut labore et dolore magna aliqua".Split(' '); posts = Enumerable.Range(0, 10_000).Select(i => { var body = string.Join(' ', Enumerable.Range(0, random.Next(5, 60)).Select(_ => words[random.Next(words.Length)])); return new Post($"Author {i % 20}", $"{random.Next(1, 59)}m ago", body); }).ToList(); } public record Post(string Author, string Time, string Body); ``` \n**Horizontal**: ```razor

@item.ToString("N0")

``` ```csharp private readonly int[] horizontalItems = Enumerable.Range(0, 100_000).ToArray(); ``` \n**Infinite scrolling**: ```razor

@item

@(feedLoading ? "Loading more..." : $"{feedItems.Count:N0} items loaded · scroll down to load more")

``` ```csharp private BitVirtualize feedRef = default!; private readonly List feedItems = [.. Enumerable.Range(0, 25).Select(i => $"Feed item {i:N0}")]; private bool feedLoading; private async Task LoadMoreFeedItems() { if (feedLoading) return; feedLoading = true; StateHasChanged(); await Task.Delay(700); // simulate a network fetch feedItems.AddRange(Enumerable.Range(feedItems.Count, 25).Select(i => $"Feed item {i:N0}")); feedLoading = false; await feedRef.RefreshDataAsync(); } ``` \n**Sticky headers**: ```razor @if (contact.IsHeader) {

@contact.Name

} else {

@contact.Name @contact.Email

}

@contact.Name

``` ```csharp private List contacts = []; protected override void OnInitialized() { var random = new Random(11); contacts = []; for (var c = 'A'; c <= 'Z'; c++) { contacts.Add(new Contact(true, c.ToString(), string.Empty)); for (var i = 0; i < random.Next(5, 20); i++) { var name = $"{c}ontact {i + 1}"; contacts.Add(new Contact(false, name, $"{name.Replace(" ", ".").ToLower()}@example.com")); } } } public record Contact(bool IsHeader, string Name, string Email); ``` \n**Reversed (chat)**: ```razor

@message.Text

Send

``` ```csharp private BitVirtualize chatRef = default!; private List messages = []; private string? draftMessage; private bool loadingChatHistory; private int chatHistoryRemaining = 381; // count of the older messages (0..380) not loaded yet protected override void OnInitialized() { // The newest messages (381..400); scrolling up loads the older ones down to 0. messages = Enumerable.Range(381, 20).Select(i => new Message(i, i % 3 == 0, $"Message number {i}")).ToList(); } private async Task SendChatMessage() { if (string.IsNullOrWhiteSpace(draftMessage)) return; var id = messages.Count == 0 ? 1000 : Math.Max(1000, messages.Max(m => m.Id) + 1); messages.Add(new Message(id, true, draftMessage.Trim())); draftMessage = string.Empty; await chatRef.RefreshDataAsync(); // Reversed mode keeps the list pinned to the bottom } private async Task LoadChatHistory() { if (loadingChatHistory || chatHistoryRemaining <= 0) return; loadingChatHistory = true; await Task.Delay(600); // simulate fetching older messages var batch = Math.Min(15, chatHistoryRemaining); messages.InsertRange(0, Enumerable.Range(chatHistoryRemaining - batch, batch).Select(i => new Message(i, i % 3 == 0, $"Message number {i}"))); chatHistoryRemaining -= batch; loadingChatHistory = false; await chatRef.RefreshDataAsync(); // Reversed mode preserves the scroll position } public record Message(int Id, bool Mine, string Text); ```