Question

我想构建一个带有IInterceptionBehavior的缓存类，如此MSDN article中的describe，我想像属性一样使用它。

但是当我测试它时，我有这个错误：类型“CacheAction”没有可访问的构造函数。我需要你的帮助来理解原因。 “CacheAction”是我给构造函数的枚举。

这是代码，没有私有方法的缓存类：

    /// <summary>
/// Cache action types.
/// </summary>
public enum CacheAction
{
    /// <summary>
    /// Add a new item to cache.
    /// </summary>
    Add,
    /// <summary>
    /// Remove all associated items from cache for the given domain model.
    /// </summary>
    Remove
}

[Serializable]
public class CacheAttribute : FilterAttribute, ICache, IInterceptionBehavior
{
    private readonly ICache _cache;

    [NonSerialized]
    private object _syncRoot;
    public readonly CacheAction _action;

    public CacheAttribute(CacheAction action)
    {
        _cache = new StaticMemoryCache();
        _action = action;
        _syncRoot = new object();
    }

    public IMethodReturn Invoke(IMethodInvocation input,
    GetNextInterceptionBehaviorDelegate getNext)
    {
        if (_action == CacheAction.Add)
        {
            var cacheKey = BuildCacheKey(input);

            // If cache is empty, execute the target method, retrieve the return value and cache it.
            if (_cache[cacheKey] == null)
            {
                lock (_syncRoot)
                {
                    // Execute the target method
                    IMethodReturn returnVal = getNext()(input, getNext);
                    // Cache the return value
                    _cache[cacheKey] = returnVal;

                    return returnVal;
                }
            }
            // Otherwise, return the cache result
            return input.CreateMethodReturn(_cache[cacheKey]);
        }
        else
        {
            var typeName = GetTypeName(input.GetType());

            lock (_syncRoot)
            {
                _cache.Remove(typeName);
            }

            IMethodReturn returnVal = getNext()(input, getNext);
            return returnVal;
        }
    }

这里是Unity配置的代码（查看InterfaceInterceptor调用）：

container.AddNewExtension<Interception>();
        container
            //.RegisterType<ICache, CacheAttribute>()
            .RegisterType<IDataContextAsync, ApplicationDbContext>(new PerRequestLifetimeManager())
           .RegisterType<IRepositoryProvider, RepositoryProvider>(
               new PerRequestLifetimeManager(),
               new InjectionConstructor(new object[] { new RepositoryFactories() })
               )
           .RegisterType<IUnitOfWorkAsync, UnitOfWork>(new PerRequestLifetimeManager())
           .RegisterType<IRepositoryAsync<Movie>, Repository<Movie>>(
                new Interceptor<InterfaceInterceptor>(),
                new InterceptionBehavior<CacheAttribute>())
           .RegisterType<IMovieService, MovieService>()
           .RegisterType<IUnitOfWorkAsync, UnitOfWork>(new PerRequestLifetimeManager());

        DependencyResolver.SetResolver(new Microsoft.Practices.Unity.Mvc.UnityDependencyResolver(container));

以下是我使用存储库进行测试的地方：

public static class MovieRepository
{
    [Cache(CacheAction.Add)]
    public static int test(this IRepositoryAsync<Movie> repository)
    {
        return 1;
    }
}

所以，需要帮助才能理解我所缺少的错误：“CacheAction”类型没有可访问的构造函数。

谢谢，

大卫

如何使用构造函数，属性和Unity的IInterceptionBehavior？

0 个答案: