public class ApiCache : ActionFilterAttribute
 {
  /// <summary>
  /// Header是否參與緩存驗證
  /// </summary>
  public bool SignHeader = false;
  /// <summary>
  /// 緩存有效時間（分鐘）
  /// </summary>
  public int CacheMinutes = 5;/// <summary>
  /// 
  /// </summary>
  /// <param name="SignHeader">Header是否參與請求體簽名</param>
  /// <param name="CacheMinutes">緩存有效時間（分鐘）</param>
  public ApiCache(bool SignHeader = false, int CacheMinutes = 5)
  {
   this.SignHeader = SignHeader;
   this.CacheMinutes = CacheMinutes;
  }


  public override void OnActionExecuting(ActionExecutingContext filterContext)
  {
   //請求體簽名
   string cacheKey = getKey(filterContext.HttpContext.Request);
   //根據簽名查詢緩存
   string data = CsRedisHepler.Get(cacheKey);
   if (!string.IsNullOrWhiteSpace(data))
   {
    //有緩存則設置返回信息
    var content = new Microsoft.AspNetCore.Mvc.ContentResult();
    content.Content = data;
    content.ContentType = "application/json; charset=utf-8";
    content.StatusCode = 200;
    filterContext.HttpContext.Response.Headers.Add("ContentType", "application/json; charset=utf-8");
    filterContext.HttpContext.Response.Headers.Add("CacheData", "Redis");
    filterContext.Result = content;
   }
  }

  public override void OnActionExecuted(ActionExecutedContext filterContext)
  {
   base.OnActionExecuted(filterContext);
  }

  public override void OnResultExecuting(ResultExecutingContext filterContext)
  {
   base.OnResultExecuting(filterContext);
  }

  public override void OnResultExecuted(ResultExecutedContext filterContext)
  {
   if (filterContext.HttpContext.Response.Headers.ContainsKey("CacheData")) return;
   //獲取緩存key
   string cacheKey = getKey(filterContext.HttpContext.Request);
   var data = JsonSerializer.Serialize((filterContext.Result as Microsoft.AspNetCore.Mvc.ObjectResult).Value);
   //如果緩存null，則設置較短過期時間（此處是防止緩存穿透）
   var disData = JsonSerializer.Deserialize<Dictionary<string, object>>(data);
   if(disData.ContainsKey("data") && disData["data"]==null)
   {
    CacheMinutes = 1;
   }
   CsRedisHepler.Set(cacheKey, data, TimeSpan.FromMinutes(CacheMinutes));
  }
  /// <summary>
  /// 請求體MDH簽名
  /// </summary>
  /// <param name="request"></param>
  /// <returns></returns>
  private string getKey(HttpRequest request)
  {
   var keyContent = request.Host.Value + request.Path.Value + request.QueryString.Value + request.Method + request.ContentType + request.ContentLength;
   try
   {
    if (request.Method.ToUpper() != "DELETE" && request.Method.ToUpper() != "GET" && request.Form.Count > 0)
    {
     foreach (var item in request.Form)
     {
      keyContent += $"{item.Key}={item.Value.ToString()}";
     }
    }
   }
   catch (Exception e)
   {

   }
   if (SignHeader)
   {
    var hs = request.Headers.Where(a => !(new string[] { "Postman-Token", "User-Agent" }).Contains(a.Key)).ToDictionary(a => a);
    foreach (var item in hs)
    {
     keyContent += $"{item.Key}={item.Value.ToString()}";
    }
   }
　　　　　　　//md5加密
   return CryptographyHelper.MD5Hash(keyContent);
  }