onecmonitor/oneswiss-server/Components/Shared/TreeView.razor

<CascadingValue Value="@(this)" IsFixed="true">
    <MudStack Spacing="0" Class="@Class">
        @if (ShowAddButton)
        {
            <MudStack Row AlignItems="AlignItems.Start" Class="mb-3">
                <MudButton Color="Color.Primary" Variant="Variant.Filled" @onclick="OnClickAddButton">Добавить
                </MudButton>
            </MudStack>
        }
        <MudPaper Class="w-100 h-100 pa-3">
            <MudStack Spacing="0" AlignItems="AlignItems.Stretch" StretchItems="StretchItems.All">
                @foreach (var item in Items)
                {
                    <TreeViewItem IsSelected="SelectedItem?.Id == item.Id" Item="item"/>
                }
            </MudStack>
        </MudPaper>
    </MudStack>
</CascadingValue>

@code
{
    private readonly List<TreeViewItem> _leafs = [];

    [Parameter] public IReadOnlyCollection<TreeItem> Items { get; set; } = [];

    [Parameter] public EventCallback<IReadOnlyCollection<TreeItem>?> ItemsChanged { get; set; }

    [Parameter] public TreeItem? SelectedItem { get; set; }

    [Parameter] public EventCallback<TreeItem?> SelectedItemChanged { get; set; }

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

    [Parameter] public bool ShowAddButton { get; set; }

    [Parameter] public Func<Task>? AddButtonCallback { get; set; }

    public async Task SelectItem(TreeItem item)
    {
        foreach (var treeViewItem in _leafs)
        {
            treeViewItem.Item.IsSelected = treeViewItem.Item.Id == item.Id;
            await treeViewItem.UpdateVisualState();
        }

        SelectedItem = item;
        await SelectedItemChanged.InvokeAsync(SelectedItem);
    }

    public void RegisterItem(TreeViewItem item)
    {
        _leafs.Add(item);
    }

    public void UnregisterItem(TreeViewItem item)
    {
        _leafs.Remove(item);
    }

    private async Task OnClickAddButton()
    {
        if (AddButtonCallback != null)
            await AddButtonCallback();
    }
}