@implements IDisposable
@inject IShoppingCartService shoppingCartService

<a href="ShoppingCart" class="btn btn-info">
    <i class="oi oi-cart"></i>&nbsp;Cart
    <span class="badge bg-dark">@shoppingCartItemCount</span>
</a>

@code {
    private int shoppingCartItemCount = 0;

    protected override void OnInitialized()
    {
        shoppingCartService.OnShoppingCartChanged += ShoppingCartChanged; //subscribe to event
    }

    protected void ShoppingCartChanged(int totalQuantity){
        shoppingCartItemCount = totalQuantity;
        StateHasChanged();
    }

    void IDisposable.Dispose()
    {
        shoppingCartService.OnShoppingCartChanged -= ShoppingCartChanged; //subscribe from event
    }
}