Asp.net 使缓存过期的最佳方法

以下是我检索所有类别的代码，它运行良好：

public static List<Category> GetAllCategories()
{
    var context = HttpContext.Current;
    var profiler = MiniProfiler.Current;
    using (profiler.Step("GetAllCategories()"))
    {
        if (context.Cache["StoreCategories"] == null)
        {
            var r = new List<Category>();
            using (var db = new MainContext())
            {
                var q = db.v2StoreCategories;
                foreach (var cat in q)
                {
                    r.Add(new Category(cat));
                }
            }
            context.Cache["StoreCategories"] = r;
        }
    }
    return (List<Category>)HttpContext.Current.Cache["StoreCategories"];
}

假设我需要以每n分钟刷新一次缓存的方式进行构建，那么最好的方法是什么

在global.asax中设置定时事件是否安全？

使用类似

Response.Cache.SetExpires(DateTime.Now.AddSeconds(60));

如适用

确保使用正确的上下文。即

HttpContext.Current

我建议你使用缓存。插入。。。方法这样，您就可以为缓存中的对象提供生存时间。大概是这样的：

public static List<Category> GetAllCategories()
{
    var context = HttpContext.Current;
    var profiler = MiniProfiler.Current;
    using (profiler.Step("GetAllCategories()"))
    {
        if (context.Cache["StoreCategories"] == null)
        {
            var r = new List<Category>();
            using (var db = new MainContext())
            {
                var q = db.v2StoreCategories;
                foreach (var cat in q)
                {
                    r.Add(new Category(cat));
                }
            }
            HttpContext.Current.Cache.Insert(
                "StoreCategories",
                r,
                null,
                DateTime.UtcNow.AddMinutes(1),  // TTL = one minute in this sample
                TimeSpan.Zero
            );
        }
    }
    return (List<Category>)HttpContext.Current.Cache["StoreCategories"];
}

以及：

HttpContext.Current.Cache.Insert(
    "StoreCategories",
    r,
    null,
    DateTime.UtcNow.AddMinutes(1),
    TimeSpan.Zero,
    UpdateCategoriesCache
);

private static void UpdateCategoriesCache(
    string key,
    System.Web.Caching.CacheItemUpdateReason reason,
    out Object categories,
    out CacheDependency dependency,
    out DateTime absoluteExpiration,
    out TimeSpan slidingExpiration
)
{
    // fetch categories here
    categories = fetchedCategories;
    dependency = null;
    absoluteExpiration = DateTime.UtcNow.AddMinutes(1);
    slidingExpiration = TimeSpan.Zero;
}