Question

我有一个简单的WCF服务，可以向应用程序发送通知。该服务包含一个静态的订阅者列表，在它尝试向其中任何一个发送消息之前，它会检查...

((ICommunicationObject)callback).State == CommunicationState.Opened

不幸的是，如果使用WCF服务的应用程序崩溃 - 因此不能从WCF服务取消订阅，该服务将会挂起并最终超时。远非理想。为了对此进行排序，我添加了

OperationContext.Current.Channel.Faulted += new EventHandler(Channel_Faulted);

在订阅方法中，但从未被击中。是否有一种可靠的方法来确定回调通道是否实际上是开放的？或者也许是异步发送消息，这样如果订阅者出现在列表中但实际上已经死了，那么服务就不会像一个极客站出来一样等待？：）

任何最乐意接受的帮助

感谢

NAT

以下服务的完整代码......

private static readonly List<INotificationCallback> subscribers = new List<INotificationCallback>();

    public void AddMessage(string SendingUser, string message, List<string> users, MessageType messageType, Guid? CaseID)
    {

        subscribers.ForEach(delegate(INotificationCallback callback)
        {

            if (((ICommunicationObject)callback).State == CommunicationState.Opened)
            {
                callback.OnMessageAdded(SendingUser, message, users, messageType, DateTime.Now, CaseID);
            }
            else
            {
                RemoveSubscriber(callback);
            }
        });
    }

    public bool Subscribe()
    {
        try
        {
            INotificationCallback callback = OperationContext.Current.GetCallbackChannel<INotificationCallback>();
            OperationContext.Current.Channel.Faulted += new EventHandler(Channel_Faulted);
            OperationContext.Current.Channel.Closed += new EventHandler(Channel_Closed);
            if (!subscribers.Contains(callback))
                subscribers.Add(callback);
            return true;
        }
        catch
        {
            return false;
        }
    }

    private void RemoveSubscriber(INotificationCallback callback)
    {
        if (subscribers.Contains(callback))
            subscribers.Remove(callback);
    }

    void Channel_Closed(object sender, EventArgs e)
    {
        INotificationCallback machine = sender as INotificationCallback;
        RemoveSubscriber(machine);
    }

    void Channel_Faulted(object sender, EventArgs e)
    {
        INotificationCallback machine = sender as INotificationCallback;
        RemoveSubscriber(machine);
    }

    public bool Unsubscribe()
    {
        try
        {
            INotificationCallback callback = OperationContext.Current.GetCallbackChannel<INotificationCallback>();
            RemoveSubscriber(callback);
            return true;
        }
        catch
        {
            return false;
        }
    }

Answer 1

最终放弃了HttpBinding并切换到NetTcpBinding，立即引发了故障事件。

WCF服务订户未提出故障事件

1 个答案: