c# - AOP Ninject 停止拦截方法被调用

Question

我正在使用 Ninject 和 AOP 进行一些缓存。我有一个属性，我可以将其应用于我的存储库中的任何方法，并且在 BeforeInvoke 上它将返回我的缓存对象(如果有的话)并且 AfterInvoke 创建一个缓存对象。这一切都很好，但我无法弄清楚如何停止调用初始方法，即如果有缓存对象，则返回它而不是调用 intyercepted 方法。我的拦截器在这里:

public class CacheInterceptor : SimpleInterceptor
{
    protected override void BeforeInvoke(IInvocation invocation)
    {
        Type returnType = invocation.Request.Method.ReturnType;
        string cacheKey = CacheKeyBuilder.GetCacheKey(invocation, serializer);
        object cachedValue = cache.Get(cacheKey);
        if (cachedValue == null)
        {
            invocation.Proceed();
        }
        else
        {
            object returnValue = serializer.Deserialize(returnType, cachedValue);
            invocation.ReturnValue = returnValue;
            returnedCachedResult = true;
        }
     }
}

即使在 else 语句中我显然没有说要调用被调用的方法 'invocation.Proceed();'它仍然调用它。我如何告诉 ninject 只返回 invocation.ReturnValue ？

Answer 1

在这种情况下，您不能使用 SimpleInterceptor，因为它是最常见场景的基类，您希望在实际方法调用之前或之后执行操作。此外，您不得调用 Proceed 而是实现 IInterceptor 接口(interface)并将您的代码放入 Intercept 方法中。

但也许我们应该在未来的版本中扩展 SimpleInterceptor，这样您就可以防止实际方法被调用:

public abstract class SimpleInterceptor : IInterceptor
{
    private bool proceedInvocation = true;

    /// <summary>
    /// Intercepts the specified invocation.
    /// </summary>
    /// <param name="invocation">The invocation to intercept.</param>
    public void Intercept( IInvocation invocation )
    {
        BeforeInvoke( invocation );
        if (proceedInvocation)
        {
            invocation.Proceed();
            AfterInvoke( invocation );
        }
    }

    /// <summary>
    /// When called in BeforeInvoke then the invokation in not proceeded anymore.
    /// Or in other words the decorated method and AfterInvoke won't be called anymore.
    /// Make sure you have assigned the return value in case it is not void.
    /// </summary>
    protected void DontProceedInvokation()
    {
        this.proceedInvocation = false;
    }

    /// <summary>
    /// Takes some action before the invocation proceeds.
    /// </summary>
    /// <param name="invocation">The invocation that is being intercepted.</param>
    protected virtual void BeforeInvoke( IInvocation invocation )
    {
    }

    /// <summary>
    /// Takes some action after the invocation proceeds.
    /// </summary>
    /// <param name="invocation">The invocation that is being intercepted.</param>
    protected virtual void AfterInvoke( IInvocation invocation )
    {
    }
}