public async Task <MessageModel <Users> > Get()
{
//if(id<=0)
// return new MessageModel<Users>() { Msg = "信息有误,请稍后再试!" };
var loginId = await _redis.GetValue("LoginId");
var user = _context.Users.AsQueryable().Where(u => u.LoginsId == loginId).FirstOrDefault();
await _redis.Set("Users", user, TimeSpan.FromMinutes(30));
user = await _redis.Get <Users>("Users");
return(new MessageModel <Users>()
{
Msg = "成功!", Success = true, Response = user
});
}
//Intercept方法是拦截的关键所在，也是IInterceptor接口中的唯一定义
public override void Intercept(IInvocation invocation)
{
var method = invocation.MethodInvocationTarget ?? invocation.Method;
//对当前方法的特性验证
var qCachingAttribute = method.GetCustomAttributes(true).FirstOrDefault(x => x.GetType() == typeof(CachingAttribute)) as CachingAttribute;
if (qCachingAttribute != null)
{
//获取自定义缓存键，这个和Memory内存缓存是一样的，不细说
var cacheKey = CustomCacheKey(invocation);
//核心1：注意这里和之前不同，是获取的string值，之前是object
var cacheValue = _cache.GetValue(cacheKey);
if (cacheValue != null)
{
//将当前获取到的缓存值，赋值给当前执行方法
var type = invocation.Method.ReturnType;
var resultTypes = type.GenericTypeArguments;
if (type.FullName == "System.Void")
{
return;
}
object response;
if (type != null && typeof(Task).IsAssignableFrom(type))
{
//核心2：返回异步对象Task<T>
if (resultTypes.Count() > 0)
{
var resultType = resultTypes.FirstOrDefault();
// 核心3，直接序列化成 dynamic 类型，之前我一直纠结特定的实体
dynamic temp = Newtonsoft.Json.JsonConvert.DeserializeObject(cacheValue, resultType);
response = Task.FromResult(temp);
}
else
{
//Task 无返回方法 指定时间内不允许重新运行
response = Task.CompletedTask;
}
}
else
{
object value = _cache.Get <object>(cacheKey);
// 核心4，要进行 ChangeType
response = System.Convert.ChangeType(value, type);
}
invocation.ReturnValue = response;
return;
}
//去执行当前的方法
invocation.Proceed();
//存入缓存
if (!string.IsNullOrWhiteSpace(cacheKey))
{
object response;
//Type type = invocation.ReturnValue?.GetType();
var type = invocation.Method.ReturnType;
if (type != null && typeof(Task).IsAssignableFrom(type))
{
var resultProperty = type.GetProperty("Result");
response = resultProperty?.GetValue(invocation.ReturnValue);
}
else
{
response = invocation.ReturnValue;
}
if (response == null)
{
response = string.Empty;
}
// 核心5：将获取到指定的response 和特性的缓存时间，进行set操作
_cache.Set(cacheKey, response, TimeSpan.FromSeconds(qCachingAttribute.AbsoluteExpiration));
}
}
else
{
invocation.Proceed();//直接执行被拦截方法
}
}