HttpContext.Current.Cache vs. HttpRuntime.Cache

.NET中Cache有两种调用方式：HttpContext.Current.Cache 和 HttpRuntime.Cache，这两种方式有什么区别呢？我们先看MSDN上的解释：

HttpContext.Current.Cache：为当前 HTTP 请求获取Cache对象。

HttpRuntime.Cache：获取当前应用程序的Cache。

我们再用.NET Reflector工具看看HttpContext.Cache和HttpRuntime.Cache的实现：

//System.Web.HttpContext.Cache属性实现

public sealed class HttpContext

//System.Web.HttpRuntime.Cache属性实现

public sealed class HttpRuntime

class CacheTest

{

static void Main(string[] args)

{

System.Web.Caching.Cache httpRuntimeCache = System.Web.HttpRuntime.Cache;

httpRuntimeCache.Insert("httpRuntimeCache", "I am stored in HttpRuntime.Cache");

if (httpRuntimeCache != null)

{

Console.WriteLine("httpRuntimeCache:" + httpRuntimeCache["httpRuntimeCache"]);

}

System.Web.HttpContext httpContext = System.Web.HttpContext.Current;

if (httpContext == null)

{

Console.WriteLine("HttpContext object is null in Console Project");

}

else

{

System.Web.Caching.Cache httpContextCache = httpContext.Cache;

httpContextCache.Insert("httpContextCache", "I am stored in HttpRuntime.Cache");

if (httpContextCache == null)

{

Console.WriteLine("httpContextCache is null");

}

}

Console.ReadLine();

}

}

输出结果：httpRuntimeCache:I am stored in HttpRuntime.Cache

HttpContext object is null in Console Project

综上：我们在使用Cache时，尽量使用HttpRuntime.Cache，既能减少出错，也减少了一次函数调用。

参考资料：HttpRuntime.Cache 与HttpContext.Current.Cache的疑问，HttpRuntime.Cache vs. HttpContext.Current.Cache