从 .net windows 服务调用宁静的 api 服务似乎不起作用

Question

I have created a windows service application which is supposed to make a call to a restful api each one minute. I am actually running the API on my localhost device and putting a breakpoint to detect if the api being called, but nothing was received.

I have then copied exact same code to a console application and it seems being working as perfect. I am really new to windows services and I don't know if have any restrictions for calling an api within a service, so could you please tell me where is the issue

=================================================================

this function will be called each 1 minute

    public async Task<DateTime> GetLastUpdatedDate(string branchName)
    {
        var VpsBaseUrl = System.Configuration.ConfigurationManager.AppSettings["VpsBaseUrl"];
        HttpResponseMessage response = await client.GetAsync($"{VpsBaseUrl}/api/transactions/{branchName}");
        if (response.IsSuccessStatusCode)
        {
            var json = await response.Content.ReadAsStringAsync();
            var result = JsonConvert.DeserializeObject<DateTime>(json);
            Console.WriteLine(result.ToString());
            return result;
        }
        else
        {
            return DateTime.Now.AddDays(-10);
        }
    }

==========================================================================

   protected override void OnStart(string[] args)
    {
        //Create a new Timer with Interval set to seconds(1 Minutes).
        System.Timers.Timer aTimer = new System.Timers.Timer(1 * 60 * 1000);
        aTimer.Elapsed += new System.Timers.ElapsedEventHandler(OnTimedEvent);
        aTimer.AutoReset = true;
        aTimer.Enabled = true;
        aTimer.Start();
    }

    protected override void OnStop(){ }

    //object source, System.Timers.ElapsedEventArgs e
    private void OnTimedEvent(object source, System.Timers.ElapsedEventArgs e)
    {
        try
        {
            var task = Task.Run(async () =>
            {
                var x =  await tProxy.GetLastUpdatedDate("branch1");
                LogHelper.AppendToLogInfo(x.ToString());
            });
        }
        catch(Exception ex)
        {
            LogHelper.AppendToLogError(ex.Message);
        }
    }

Answer 1

Let me clear you few points.

1. There is no different between calling API from Window Service or Window Form or Any Web API.

2. Context is important if account under which API execute does not have permission. (This could be second thing you can check).

3. One thing I will correct is

    var task = Task.Run(async () => { var x = await tProxy.GetLastUpdatedDate("branch1"); LogHelper.AppendToLogInfo(x.ToString()); }); task.Wait(); // It seems that you are missing this.

if you don't wait then it goes to next line and in your case it will get out of scope so possibly garbage collected.

Answer 2

It's possible that your configuration is not being read correctly in the Win32 service. Win32 services have their working directory set differently than console applications.

Try putting the following line of code at the top of your Main method:

Directory.SetCurrentDirectory(AppDomain.CurrentDomain.BaseDirectory);