FluentTreeView fill from hierarchical structure

[DomenicoFormoso]

Maybe it's out of this context but I'm asking how to fill FluentTreeView from a data structure like:

Id, IdParent, Text

Thanks

[dvoituron]

You have an example here, using the ITreeViewItem.
https://www.fluentui-blazor.net/TreeView#dynamictreegeneratio

[DomenicoFormoso]

yes I saw, but my code is terribly slow (15 seconds 420 records)

@using Microsoft.EntityFrameworkCore;
<FluentTreeView Items="@Items" @bind-SelectedItem="@SelectedItem" LazyLoadItems="false">
    <ItemTemplate>
        @context.Text
    </ItemTemplate>
</FluentTreeView>
<div>
    <b>Selezionato:</b> @SelectedItem?.Text
</div>

@code {
    private ITreeViewItem? SelectedItem;
    private IEnumerable<ITreeViewItem>? Items = new List<ITreeViewItem>();
    protected async override void OnInitialized()
    {
        Items = CreateTree(-1);
    }
    private IEnumerable<ITreeViewItem> CreateTree(int level)
    {
        var albero = new List<ITreeViewItem>();
        using var dbT = new TabGestio();
        var ta = dbT.Tipoarticolos.Where(x => x.Parent == level).Select(x => new { x.Idtipoarticolo, x.Descrizione }).ToList();
        if (ta.Any())
        {
            foreach (var dato in ta)
            {
                var ramo = new TreeViewItem
                {
                    Text = dato.Descrizione,
                    Id = dato.Idtipoarticolo.ToString(),
                    Items = CreateTree(dato.Idtipoarticolo)
                };
                albero.Add(ramo);
            }
            return albero;
        }
        else
            return albero;
    }
}

[DomenicoFormoso]

this way it's much better:

@using Microsoft.EntityFrameworkCore;
@rendermode InteractiveServer

<FluentTreeView Items="@Items" SelectedItemChanged="OnSelected" >
    <ItemTemplate>
        @context.Text
    </ItemTemplate>
</FluentTreeView>
<div>
    <b>Selected item:</b> @SelectedItem?.Text [@SelectedItem?.Id]
</div>

 private ITreeViewItem? SelectedItem;

 private Icon IconCollapsed = new Icons.Regular.Size20.Folder();
 private Icon IconExpanded = new Icons.Regular.Size20.FolderOpen();

 private IEnumerable<ITreeViewItem>? Items = new List<ITreeViewItem>();

 protected async override void OnInitialized()
 {
     //Items = await CreaAlbero(-1);

     await Root();
     StateHasChanged();
 }

 private async Task Root()
 {
     using var dbT = new TabGestio();
     var ta = await dbT.Tipoarticolos.Where(x => x.Parent == -1).Select(x => new { x.Idtipoarticolo, x.Descrizione }).ToListAsync();
     var albero = new List<ITreeViewItem>();
     foreach (var dato in ta)
     {
         var ramo = new TreeViewItem
         {
             Text = dato.Descrizione,
             Id = dato.Idtipoarticolo.ToString(),
             IconCollapsed = IconCollapsed,
             IconExpanded = IconExpanded,
             Expanded = true,
             Items = new List<ITreeViewItem>()
         };
         albero.Add(ramo);
     }
     Items = albero;
 }


 private async Task OnSelected(ITreeViewItem? selectedItem)
 {
     if (selectedItem != null)
     {
         SelectedItem = selectedItem;
         int IdParent = Convert.ToInt32(selectedItem.Id);

         using var dbT = new TabGestio();
         var ta = await dbT.Tipoarticolos.Where(x => x.Parent == IdParent).Select(x => new { x.Idtipoarticolo, x.Descrizione }).ToListAsync();

         var albero = new List<ITreeViewItem>();
         foreach (var dato in ta)
         {
             var ramo = new TreeViewItem
             {
                 Text = dato.Descrizione,
                 Id = dato.Idtipoarticolo.ToString(),
                 IconCollapsed = IconCollapsed,
                 IconExpanded = IconExpanded,
                 Expanded = true,
                 Items = new List<ITreeViewItem>()
             };
             albero.Add(ramo);
         }
         selectedItem.Items = albero;
     }
 }