HTTP-based caching

To control the browsers cache you can set a Cache-Control HTTP header. Usually, the StaticFileMiddleware doesn't set a Cache-Control header. This means the clients are free to cache how they prefer. If you like to limit the cache time to just one day, you can do this by passing StaticFileOptions to the middleware:

const string cacheMaxAge = "86400";
app.UseStaticFiles(new StaticFileOptions()
{
    OnPrepareResponse = ctx =>
    {
        ctx.Context.Response.Headers.TryAdd(
            "Cache-Control", 
            $"public, max-age={cacheMaxAge}");
    }
});

This sets the Cache-Control header to every static file that is requested before it gets sent to the client. The Cache-Control is set to public, which...