Question

假设我想要从MarketDataProvider类发布一个事件。问题是事件逻辑更深层次。MarketDataProvider - ＆gt; Level1SocketClient - ＆gt; Level1MessageHandler。

简而言之，我想提出Level1MessageHandler MarketDataProvider可以发布的事件。此处的性能至关重要，因为生成了大量事件。我想找到一种干净的方式来做到这一点，而不是从每个级别链接事件。

Answer 1

中间类可以将Add和Remove调用传递给最低级别的类，而不是拥有一个Event本身吗？即

public class Level1MessageHandler
{
    public event EventHandler<MessageEventArgs> MessageReceived;
}

public class Level1SocketClient
{
    Level1MessageHandler level1Handler;

    public event EventHandler<MessageEventArgs> MessageReceived 
    {
        add 
        {
            level1Handler.MessageReceived += value;
        }
        remove 
        {
            level1Handler.MessageReceived -= value;
        }
    }
}

这至少会削减一级代表电话。

（或者我的调用方向是否被颠倒？无论如何，我认为这个想法很明确。）

更新

出现了一个有趣的问题：如果中间监听器需要是一次性的，并且在处理时，会删除通过它添加的所有事件，会发生什么？您可以通过记录在本地事件中添加的事件来实现，如下所示：

public interface IMessagePublisher<TEventArgs> where TEventArgs : EventArgs
{
    event EventHandler<TEventArgs> MessageReceived;
}

public class MessageRePublisher<TEventArgs> : IMessagePublisher<TEventArgs>, IDisposable where TEventArgs : EventArgs
{
    readonly IMessagePublisher<TEventArgs> publisher;

    public MessageRePublisher(IMessagePublisher<TEventArgs> publisher)
    {
        this.publisher = publisher;
    }

    EventHandler<TEventArgs> messageReceivedEventsAdded = null;

    public event EventHandler<TEventArgs> MessageReceived 
    {
        [MethodImpl(MethodImplOptions.Synchronized)]
        add 
        {
            // events are multicast delegates, which are immutable.  We need to remove the previous
            // combined event, create a new combined event, then added that.
            // More here: http://msdn.microsoft.com/en-us/magazine/cc163533.aspx
            if (messageReceivedEventsAdded != null)
                publisher.MessageReceived -= messageReceivedEventsAdded;
            messageReceivedEventsAdded += value;
            if (messageReceivedEventsAdded != null)
                publisher.MessageReceived += messageReceivedEventsAdded;
        }
        [MethodImpl(MethodImplOptions.Synchronized)]
        remove 
        {
            if (messageReceivedEventsAdded != null)
                publisher.MessageReceived -= messageReceivedEventsAdded;
            messageReceivedEventsAdded -= value;
            if (messageReceivedEventsAdded != null)
                publisher.MessageReceived += messageReceivedEventsAdded;
        }
    }

    #region IDisposable Members

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (disposing)
        {
            if (messageReceivedEventsAdded != null && publisher != null)
            {
                publisher.MessageReceived -= messageReceivedEventsAdded;
            }
        }
        messageReceivedEventsAdded = null;
    }

    #endregion
}

中间监听器将其所有事件组合成一个连接事件，然后每次添加和删除它。

具有极高性能的C＃Inter class通信

1 个答案: