Can the state of the Counter in the example Blazor project be preserved between page switches?

Question

In the default example project for both server-side Blazor and WebAssembly Blazor projects, the Counter example resets to 0 every time you move between the pages. However, o

Answer 1

For server side Blazor if you want the counter value to be persisted/updated on all tabs/clients you could simply store it in a static variable and rerender if the value changes.

@page "/counter"

Static Counter

Current static count: @currentCount

Click me

@code {
    public static int currentCount = 0;

    private void IncrementCount()
    {
        currentCount++;

        StaticCount.FireUpdate();
    }

    protected override void OnInitialized()
    {
        base.OnInitialized();

        StaticCount.NewCounterValue += OnNewCounterValue;
    }

    void OnNewCounterValue(object sender, EventArgs e)
    {
        InvokeAsync(() =>
        {
            StateHasChanged();
        });
    }

    public void Dispose()
    {
        StaticCount.NewCounterValue -= OnNewCounterValue;
    }

}

@code{
    public static class StaticCount
    {
        public static event EventHandler NewCounterValue;

        public static void FireUpdate()
        {
            NewCounterValue?.Invoke(null, new EventArgs());
        }
    }
}

You could also do this with a (singleton) service and even persist the value in a database if you want to keep the value between server restarts.