C# 内存缓存帮助类

using System;
using System.Runtime.Caching;
namespace MyTools
{
    /// <summary>
    /// 缓存类,此类型是线程安全的
    /// </summary>
    public class CacheHelper
    {
        private static ObjectCache cache = MemoryCache.Default;

        /// <summary>
        /// 读
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public static object GetCache(string key)
        {
            var obj = cache.Get(key);
            return obj;
        }

        /// <summary>
        /// 写
        /// </summary>
        /// <param name="key"></param>
        /// <param name="obj"></param>
        /// <param name="timeout">过期时间,默认7200秒</param>
        public static void SetCache(string key, object obj, int timeout = 7200)
        {
            cache.Set(key, obj, DateTimeOffset.Now.AddSeconds(timeout));
        }

        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="key"></param>
        public static void RemoveCache(string key)
        {
            cache.Remove(key);
        }

    }
}