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c#asp.netasp.net-core.net-corememorycache

Asp.Net Core: Use memory cache outside controller


In ASP.NET Core its very easy to access your memory cache from a controller

In your startup you add:

public void ConfigureServices(IServiceCollection services)
        {
             services.AddMemoryCache();
        }

and then from your controller

[Route("api/[controller]")]
public class MyExampleController : Controller
{
    private IMemoryCache _cache;

    public MyExampleController(IMemoryCache memoryCache)
    {
        _cache = memoryCache;
    }

    [HttpGet("{id}", Name = "DoStuff")]
    public string Get(string id)
    {
        var cacheEntryOptions = new MemoryCacheEntryOptions().SetAbsoluteExpiration(TimeSpan.FromHours(1));
        _cache.Set("key", "value", cacheEntryOptions);
    }
}

But, how can I access that same memory cache outside of the controller. eg. I have a scheduled task that gets initiated by HangFire, How do I access the memorycache from within my code that starts via the HangFire scheduled task?

public class ScheduledStuff
{
    public void RunScheduledTasks()
    {
        //want to access the same memorycache here ...
    }
}

Solution

  • Memory cache instance may be injected to the any component that is controlled by DI container; this means that you need configure ScheduledStuff instance in the ConfigureServices method:

    public void ConfigureServices(IServiceCollection services) {
      services.AddMemoryCache();
      services.AddSingleton<ScheduledStuff>();
    }
    

    and declare IMemoryCache as dependency in ScheduledStuff constructor:

    public class ScheduledStuff {
      IMemoryCache MemCache;
      public ScheduledStuff(IMemoryCache memCache) {
        MemCache = memCache;
      }
    }