.Net Core MemoryCache-权限菜单缓存

 1    public interface ICache
 2     {
 3         /// <summary>
 4         /// 读取缓存
 5         /// </summary>
 6         /// <typeparam name="T"></typeparam>
 7         /// <param name="key"></param>
 8         /// <returns></returns>
 9         T Get<T>(string key);
10         /// <summary>
11         /// 设置缓存
12         /// </summary>
13         /// <param name="key"></param>
14         /// <param name="data"></param>
15         /// <param name="cachetime"></param>
16         void Add<T>(string key, T data, ObsloteType obsloteType = default, int cachetime =  30);
17         /// <summary>
18         /// 是否包含
19         /// </summary>
20         /// <param name="key"></param>
21         /// <returns></returns>
22         bool Contains(string key);
23         /// <summary>
24         /// 清除缓存
25         /// </summary>
26         /// <param name="key"></param>
27         bool Remove(string key);
28         /// <summary>
29         /// 更新缓存
30         /// </summary>
31         /// <param name="key"></param>
32         /// <returns></returns>
33         bool Upate<T>(string key,T data, ObsloteType obsloteType = default, int cacheMin =  30);
34        
35     }

 1  /// <summary>
 2     /// Cache策略类型  永久/绝对过期/滑动过期
 3     /// </summary>
 4     public enum ObsloteType
 5     {
 6         /// <summary>
 7         /// 永久
 8         /// </summary>
 9         Never,
10         /// <summary>
11         /// 绝对过期
12         /// </summary>
13         Absolutely,
14         /// <summary>
15         /// 滑动过期 如果期间查询或更新，就再次延长
16         /// </summary>
17         Relative
18     }

1 services.AddMemoryCache(options =>
2 {
3    //最大缓存空间大小限制为 1024
4    options.SizeLimit = 1024;
5    //缓存策略设置为缓存压缩比为 2%
6    options.CompactionPercentage = 0.02d;
7    //每 5 分钟进行一次过期缓存的扫描
8    options.ExpirationScanFrequency = TimeSpan.FromMinutes(5);
9 });

1 private readonly IMemoryCache _memoryCache;
2 public HomeController(IMemoryCache memoryCache)
3 {
4             _memoryCache = memoryCache;
5 }

public IActionResult Index()
{
  _memoryCache.Set<string>("timestamp", DateTime.Now.ToString());
  return View();
}

public IActionResult Show()
{
  string timestamp = _memoryCache.Get<string>("timestamp");
  return View("Show",timestamp);
}

if (!_memoryCache.TryGetValue<string>
("timestamp", out string timestamp))
{
    _memoryCache.Set<string>("timestamp", DateTime.Now.ToString());
}

public IActionResult Show()
{
  string timestamp = cache.GetOrCreate<string>
  ("timestamp", entry => {
return DateTime.Now.ToString(); });
  return View("Show",timestamp);
}
 

1 MemoryCacheEntryOptions options = new MemoryCacheEntryOptions();
2 options.AbsoluteExpiration = DateTime.Now.AddMinutes(1);
3 options.SlidingExpiration = TimeSpan.FromMinutes(1);
4 _memoryCache.Set<string>("timestamp", DateTime.Now.ToString(), options);

  services.AddScoped(typeof(MemoryCacheExtensions));

 1 private readonly Frame_RelationsService _service;
 2 private readonly MemoryCacheExtensions _memoryCacheExtensions;
 3 public FrameRelationsController(Frame_RelationsService service,  MemoryCacheExtensions  memoryCacheExtensions)
 4 {
 5   _service = service;
 6    _memoryCacheExtensions = memoryCacheExtensions;
 7 }
 8  
 9 [AllowAnonymous]
10 public string LoadRoleMenu( )
11 {
12    PageResponse resp = new PageResponse();
13    string KeyName = "Menu_" + CurrentUser.ID;
14      //第一次加载 判断是否有Key为"Keyname"的缓存
15    if (_memoryCacheExtensions.Contains(KeyName))
16    {
17       resp.Message = _memoryCacheExtensions.Get<string>(KeyName);
18    }
19    else
20    {
21          //返回菜单权限的信息
22      resp.Message = _service.LoadRoleMenu(CurrentUser.RoleID);
23      _memoryCacheExtensions.Add<string>(KeyName, resp.Message);
24    }
25    return  JsonHelper.Instance.Serialize(Newtonsoft.Json.Linq.JArray.Parse(resp.Message));
26  }