Pass async Callback to Timer constructor

Question

I have async callback, which is passed into Timer(from System.Threading) constructor :

private async Task HandleTimerCallback(object state)
{
    if (timer == nu         


        

Answer 1

You could use a wrapper method, as recommended by David Fowler here:

public class Pinger
{
    private readonly Timer _timer;
    private readonly HttpClient _client;
    
    public Pinger(HttpClient client)
    {
        _client = client;
        _timer = new Timer(Heartbeat, null, 1000, 1000);
    }

    public void Heartbeat(object state)
    {
        // Discard the result
        _ = DoAsyncPing();
    }

    private async Task DoAsyncPing()
    {
        await _client.GetAsync("http://mybackend/api/ping");
    }
}

Answer 2

Is there any way to omit that o param in lambda?

Sure, just define your event handler method as async void:

private async void HandleTimerCallback(object state)