这是我用来处理通道工厂的辅助类：
public class ChannelFactoryManager : IDisposable
{
private static Dictionary<Type, ChannelFactory> _factories = new Dictionary<Type,ChannelFactory>();
private static readonly object _syncRoot = new object();
public virtual T CreateChannel<T>() where T : class
{
return CreateChannel<T>("*", null);
}
public virtual T CreateChannel<T>(string endpointConfigurationName) where T : class
{
return CreateChannel<T>(endpointConfigurationName, null);
}
public virtual T CreateChannel<T>(string endpointConfigurationName, string endpointAddress) where T : class
{
T local = GetFactory<T>(endpointConfigurationName, endpointAddress).CreateChannel();
((IClientChannel)local).Faulted += ChannelFaulted;
return local;
}
protected virtual ChannelFactory<T> GetFactory<T>(string endpointConfigurationName, string endpointAddress) where T : class
{
lock (_syncRoot)
{
ChannelFactory factory;
if (!_factories.TryGetValue(typeof(T), out factory))
{
factory = CreateFactoryInstance<T>(endpointConfigurationName, endpointAddress);
_factories.Add(typeof(T), factory);
}
return (factory as ChannelFactory<T>);
}
}
private ChannelFactory CreateFactoryInstance<T>(string endpointConfigurationName, string endpointAddress)
{
ChannelFactory factory = null;
if (!string.IsNullOrEmpty(endpointAddress))
{
factory = new ChannelFactory<T>(endpointConfigurationName, new EndpointAddress(endpointAddress));
}
else
{
factory = new ChannelFactory<T>(endpointConfigurationName);
}
factory.Faulted += FactoryFaulted;
factory.Open();
return factory;
}
private void ChannelFaulted(object sender, EventArgs e)
{
IClientChannel channel = (IClientChannel)sender;
try
{
channel.Close();
}
catch
{
channel.Abort();
}
throw new ApplicationException("Exc_ChannelFailure");
}
private void FactoryFaulted(object sender, EventArgs args)
{
ChannelFactory factory = (ChannelFactory)sender;
try
{
factory.Close();
}
catch
{
factory.Abort();
}
Type[] genericArguments = factory.GetType().GetGenericArguments();
if ((genericArguments != null) && (genericArguments.Length == 1))
{
Type key = genericArguments[0];
if (_factories.ContainsKey(key))
{
_factories.Remove(key);
}
}
throw new ApplicationException("Exc_ChannelFactoryFailure");
}
public void Dispose()
{
Dispose(true);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
lock (_syncRoot)
{
foreach (Type type in _factories.Keys)
{
ChannelFactory factory = _factories[type];
try
{
factory.Close();
continue;
}
catch
{
factory.Abort();
continue;
}
}
_factories.Clear();
}
}
}
}
接着我定义了一个服务调用器：
public interface IServiceInvoker
{
R InvokeService<T, R>(Func<T, R> invokeHandler) where T: class;
}
以及一个实现：
public class WCFServiceInvoker : IServiceInvoker
{
private static ChannelFactoryManager _factoryManager = new ChannelFactoryManager();
private static ClientSection _clientSection = ConfigurationManager.GetSection("system.serviceModel/client") as ClientSection;
public R InvokeService<T, R>(Func<T, R> invokeHandler) where T : class
{
var endpointNameAddressPair = GetEndpointNameAddressPair(typeof(T));
T arg = _factoryManager.CreateChannel<T>(endpointNameAddressPair.Key, endpointNameAddressPair.Value);
ICommunicationObject obj2 = (ICommunicationObject)arg;
try
{
return invokeHandler(arg);
}
finally
{
try
{
if (obj2.State != CommunicationState.Faulted)
{
obj2.Close();
}
}
catch
{
obj2.Abort();
}
}
}
private KeyValuePair<string, string> GetEndpointNameAddressPair(Type serviceContractType)
{
var configException = new ConfigurationErrorsException(string.Format("No client endpoint found for type {0}. Please add the section <client><endpoint name=\"myservice\" address=\"http://address/\" binding=\"basicHttpBinding\" contract=\"{0}\"/></client> in the config file.", serviceContractType));
if (((_clientSection == null) || (_clientSection.Endpoints == null)) || (_clientSection.Endpoints.Count < 1))
{
throw configException;
}
foreach (ChannelEndpointElement element in _clientSection.Endpoints)
{
if (element.Contract == serviceContractType.ToString())
{
return new KeyValuePair<string, string>(element.Name, element.Address.AbsoluteUri);
}
}
throw configException;
}
}
现在，每当您需要调用WCF服务时，您可以使用以下内容：
WCFServiceInvoker invoker = new WCFServiceInvoker();
SomeReturnType result = invoker.InvokeService<IMyServiceContract, SomeReturnType>(
proxy => proxy.SomeMethod()
);
假设您已经在配置文件中定义了IMyServiceContract服务契约的客户端终端点:
<client>
<endpoint
name="myservice"
address="http://example.com/"
binding="basicHttpBinding"
contract="IMyServiceContract" />
</client>
((IClientChannel)local).Faulted += ChannelFaulted时，默认情况下return invokeHandler(arg);行不会抛出异常。我猜这就是为什么添加了throw new ApplicationException("Exc_ChannelFailure");的原因。有人找到了获取原始异常的方法吗？ - Nelson Rothermel