CacheHelperApiController.cs

using System.Web.Http;
using Umbraco.Core.Cache;
using Umbraco.Web;
using Umbraco.Web.Mvc;
using Umbraco.Web.WebApi;
using Umbraco.Web.Cache;
using Umbraco.Core.Services.Changes;

namespace Our.Umbraco.Web.Controllers
{
    // Accessed via /umbraco/api/CacheHelperApi/ClearCaches
    public class CacheHelperApiController : UmbracoApiController // UmbracoAuthorizedApiController
    {
        private AppCaches _appCaches;
        private DistributedCache _distributedCache;

        public CacheHelperApiController(AppCaches appCaches, DistributedCache distributedCache)
        { 
            _appCaches = appCaches;
            _distributedCache = distributedCache;
        }

        [HttpGet]
        public void ClearCaches()
        {
            // Clear system caches
            _appCaches.RequestCache.Clear();
            _appCaches.RuntimeCache.Clear(); 
            _appCaches.IsolatedCaches.ClearAllCaches();

            // Clear NuCache memory cache
            _distributedCache.RefreshByPayload(ContentCacheRefresher.UniqueId, new[] { new ContentCacheRefresher.JsonPayload(0, null, TreeChangeTypes.RefreshAll) });
            _distributedCache.RefreshByPayload(MediaCacheRefresher.UniqueId, new[] { new MediaCacheRefresher.JsonPayload(0, null, TreeChangeTypes.RefreshAll) });
            _distributedCache.RefreshByPayload(DomainCacheRefresher.UniqueId, new[] { new DomainCacheRefresher.JsonPayload(0, DomainChangeTypes.RefreshAll) }); 
        }
    }
}