Load controller at startup - web Api core

Question

Hi
Can we call a controller after startup in Web Api Core?

I would like to call a method which saves some data in the cache memory after startup.

Answer 1

Can we call a controller after startup in Web Api Core? I would like to call a method which saves some data in the cache memory after startup.

Move the cache code into a service/class that can be called from the startup.cs file and the Web API Core action.

Answer 2

Hi juanmaximilianoaguilarabanto-6444,

As far as I know, we could run method after asp.net core application started. You could try to use IHostApplicationLifetime's ApplicationStarted method.

This method will be called after the application started immediately.

You could inject IHostApplicationLifetime into Configure() method , then write the callback for ApplicationStarted that would be triggered when the application host has fully started.

More details, you could refer to below example:

Register httpclient service in Startup.cs ConfigureServices method

    public void ConfigureServices(IServiceCollection services)
    {

        services.AddHttpClient();

        services.AddControllersWithViews();


    }

Add lifetime.ApplicationStarted.Register callback in Configure method:

  public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IHostApplicationLifetime lifetime)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        app.UseStaticFiles();


        app.UseRouting();
        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {               
            endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Default}/{action=Index}/{id?}");             

        });

        IHttpClientFactory httpClientFactory = app.ApplicationServices.GetService(typeof(IHttpClientFactory)) as IHttpClientFactory;

        lifetime.ApplicationStarted.Register(onApplicationStartedAsync(httpClientFactory).Wait);
    }



    private async Task<Action> onApplicationStartedAsync(IHttpClientFactory httpClientFactory)
    {

        var httpclient = httpClientFactory.CreateClient();

        var httpMessage = new HttpRequestMessage(HttpMethod.Get, "http://localhost:5000/api/values");

        var httpresponse = await httpclient.SendAsync(httpMessage);

        if (httpresponse.IsSuccessStatusCode)
        {
            string res = await httpresponse.Content.ReadAsStringAsync();
        }

        return null;
    }

Result: