public class Startup
{
	public void ConfigureServices(IServiceCollection services)
	{
		// ....
		services.AddMemcached(options => Configuration.GetSection("Memcached").Bind(options));
	}
	
	public void Configure(IApplicationBuilder app, IHostingEnvironment env)
	{ 
		// ....
		app.UseMemcached();
	}
}

public class TabNavService
{
	ITabNavRepository _tabNavRepository;
	IMemcachedClient _cache;

	public TabNavService(ITabNavRepository tabNavRepository, IMemcachedClient cache)
	{
		_tabNavRepository = tabNavRepository;
		_cache = cache;
	}

	public async Task<IEnumerable<TabNav>> GetAllAsync()
	{
		var cacheKey = "aboutus_tabnavs_all";
		var result = await _cache.GetAsync<IEnumerable<TabNav>>(cacheKey);
		if (result == null)
		{
			var tabNavs = await _tabNavRepository.GetAll();
			await _cache.SetAsync(cacheKey, tabNavs, TimeSpan.FromMinutes(30));
			return tabNavs;
		}
		else
			return result;
	}
}

public class CreativeService
{
	ICreativeRepository _creativeRepository;
	IDistributedCache _cache;

	public CreativeService(ICreativeRepository creativeRepository, IDistributedCache cache)
	{
		_creativeRepository = creativeRepository;
		_cache = cache;
	}

	public async Task<IList<CreativeDTO>> GetCreativesAsync(string unitName)
	{
		var cacheKey = $"creatives_{unitName}";
		IList<CreativeDTO> creatives = null;

		var creativesBytes = await _cache.GetAsync(cacheKey);
		var creativesJson = creativesBytes != null ? System.Text.Encoding.UTF8.GetString(creativesBytes) : null;
		if (creativesJson == null)
		{
			creatives = await _creativeRepository.GetCreatives(unitName).ProjectTo<CreativeDTO>().ToListAsync();
			var json = creatives != null && creatives.Count() > 0 ? JsonConvert.SerializeObject(creatives) : string.Empty;
			creativesBytes = System.Text.Encoding.UTF8.GetBytes(json);
			await _cache.SetAsync(cacheKey, creativesBytes, new DistributedCacheEntryOptions().SetSlidingExpiration(TimeSpan.FromMinutes(30)));
		}
		else
			creatives = JsonConvert.DeserializeObject<List<CreativeDTO>>(creativesJson);

		return creatives;
	}
}

public class CreativeService
{
	MemcachedClient _cache;

	public CreativeService()
	{
		_cache = new MemcachedClient(ConfigurationManager.GetSection("memcached") as MemcachedClientConfigurationSectionHandler);
	}

	public async Task<IList<CreativeDTO>> GetCreativesAsync(string unitName)
	{
		return await _cache.GetAsync<IList<CreativeDTO>>($"creatives_{unitName}");
	}
}