using System;

using Microsoft.Extensions.DependencyInjection;

using Microsoft.Extensions.Caching.Memory;

using Microsoft.Extensions.Hosting;

​

HostApplicationBuilder builder = Host.CreateApplicationBuilder(args);

​

builder.Services.AddTransient<IMyService, MyService>();

// uncomment the line below to show a working version

builder.Services.AddMemoryCache();

​

using IHost host = builder.Build();

// injecting the service 

Console.WriteLine("Starting the application");

​

MyProgram(host.Services.GetRequiredService<IMyService>());

await host.RunAsync();

​

static void MyProgram(IMyService svc){

    Console.WriteLine("Attempting to save the item into memory");

    svc.SaveIt("key","value");

}

​

public interface IMyService{

    void SaveIt(string key,string val);

}

public class MyService : IMyService {

    private readonly IMemoryCache cache;

    public MyService(IMemoryCache cache){

        this.cache = cache;

    }

    public void SaveIt(string key,string val){

        cache.Set(key, val, TimeSpan.FromDays(1));

        // read it out to show it was  there

        var item = cache.Get(key);      

        Console.WriteLine(item.ToString());

    }

}