HttpContext.Current.Cache item null after page refresh

Question

I\'ve a C# web page in which I\'m storing a List<> object in the server cache, using HttpContext.Current.Cache. The object is saved in the cache after the first page load

Answer 1

Can you use the System.Runtime.Caching instead. That way you're not dependent on the HttpRuntime namespace.

I suspect you're getting null because .Net is clearing it due to web-server restarts. Would it be better to do something along the lines of

    public List GetUsers()
    {
        var cache = System.Runtime.Caching.MemoryCache.Default;
        if (cache["MainADList"] == null)
        {
            // Rebuild cache. Perhaps for Multithreading, you can do object locking
            var cachePolicy = new System.Runtime.Caching.CacheItemPolicy() { AbsoluteExpiration = DateTime.Now + TimeSpan.FromMinutes(30) };
            var users = Uf.GetUsers();
            cache.Add(new System.Runtime.Caching.CacheItem("MainADList", users), cachePolicy);

            return users;
        }

        return cache["MainADList"] as List; 
    }