c# - 处置由 WCF ChannelFactory 创建的 Channel

Question

我正在寻找一种干净的方式让ChannelFactory 为我创建 channel ，并在使用后能够处理它们。< br/>这是我得到的:

public class ClientFactory : IClientFactory
{
    private const string endpointName = "IMyService";
    private readonly ChannelFactory<IMyService> _factory;

    public ClientFactory()
    {
        _factory = new ChannelFactory<IMyService>(endpointName);
    }

    public Client<IMyService> GetClient()
    {       
        IMyService channel = _factory.CreateChannel();
        return new Client<IMyService>(channel);
    }
}

public class Client<T> : IDisposable
{
    public T Channel { get; private set; }

    public Client(T channel)
    {
        if (channel == null)
            throw new ArgumentException("channel");

        Channel = channel;
    }

    public void Dispose()
    {
        (Channel as IDisposable).Dispose();
    }
}

//usage
using (var client = _serviceFactory.GetClient())
{
    client.Channel.DoStuff();
}

这是一个好的解决方案吗？
有没有更简洁的方法来做到这一点？

Answer 1

不，没有更干净的方式来包装 channel 。

另一种方法是改用 Action/Func。它不是更干净，但可能更适合您的应用程序。

我是这样做的:

internal class WrappedClient<T, TResult> : IDisposable
{
    private readonly ChannelFactory<T> _factory;
    private readonly object _channelLock = new object();
    private T _wrappedChannel;

    public WrappedClient(ChannelFactory<T> factory)
    {
        _factory = factory;
    }

    protected T WrappedChannel
    {
        get
        {
            lock (_channelLock)
            {
                if (!Equals(_wrappedChannel, default(T)))
                {
                    var state = ((ICommunicationObject)_wrappedChannel).State;
                    if (state == CommunicationState.Faulted)
                    {
                        // channel has been faulted, we want to create a new one so clear it
                        _wrappedChannel = default(T);
                    }
                }

                if (Equals(_wrappedChannel, default(T)))
                {
                    _wrappedChannel = _factory.CreateChannel();
                }
            }

            return _wrappedChannel;
        }
    }

    public TResult Invoke(Func<T, TResult> func)
    {
        try
        {
            return func(WrappedChannel);
        }
        catch (FaultException)
        {
            throw;
        }
        catch (CommunicationException)
        {
            // maybe retry works
            return func(WrappedChannel);
        }
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!disposing ||
            Equals(_wrappedChannel, default(T)))
            return;

        var channel = _wrappedChannel as ICommunicationObject;
        _wrappedChannel = default(T);
        try
        {
            channel.Close();
        }
        catch (CommunicationException)
        {
            channel.Abort();
        }
        catch (TimeoutException)
        {
            channel.Abort();
        }
    }

    public void Dispose()
    {
        Dispose(true);
    }
}

然后你像这样使用服务

client.Invoke(channel => channel.DoStuff())