ant-design-blazor/components/layout/Layout.razor

@namespace AntDesign
@inherits AntDomComponentBase


<CascadingValue Value="this" IsFixed="@true">
    <section class="@ClassMapper.Class" style="@Style" id="@Id">
        @ChildContent
    </section>
</CascadingValue>

@code
     {
    [Parameter]
    public RenderFragment ChildContent { get; set; }

    private bool _hasSider;


    protected override void OnInitialized()
    {
        base.OnInitialized();
        ClassMapper
            .Add("ant-layout")
            .If("ant-layout-has-sider", () => _hasSider);
    }

    internal void HasSider()
    {
        _hasSider = true;
        StateHasChanged();
    }

}