WCF发现根本不起作用

Question

我正在尝试将ad-hoc发现添加到简单的WCF服务 - 客户端设置(当前通过控制台应用程序中的自托管实现).在Windows 7上使用VS2010进行调试,并执行我在在线教程中可以找到的任何内容,但仍然 - 发现客户端根本找不到任何内容.不用说,如果我打开客户端到正确的服务端点,我可以从客户端访问服务.

服务代码:

using (var selfHost = new ServiceHost(typeof(Renderer)))
{
    try
    {
        selfHost.Open();
        ...
        selfHost.Close();

service app.config:

<?xml version="1.0"?>
<configuration>
  <system.serviceModel>
    <services>
      <service name="TestApp.Renderer">
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:9000" />
          </baseAddresses>
        </host>
        <endpoint address="ws" binding="wsHttpBinding" contract="TestApp.IRenderer"/>
        <endpoint kind="udpDiscoveryEndpoint"/>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <serviceDiscovery/>
          <serviceMetadata httpGetEnabled="True"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
</configuration>

客户端发现代码:

DiscoveryClient discoveryClient = new DiscoveryClient(new UdpDiscoveryEndpoint());
var criteria = new FindCriteria(typeof(IRenderer)) { Duration = TimeSpan.FromSeconds(5) };
var endpoints = discoveryClient.Find(criteria).Endpoints;

"端点"集合总是空洞的.我试过从调试器,从命令行,从管理命令行运行服务和客户端 - 一切,但无济于事(当然,所有在本地机器上,不是我需要它运行我的整个子网最终)

任何帮助,将不胜感激 :-)

Answer 1

这是一个超级简单的发现示例.它不使用配置文件,它都是c#代码,但您可以将概念移植到配置文件中.

在主机和客户端程序之间共享此接口(现在复制到每个程序)

[ServiceContract]
public interface IWcfPingTest
{
  [OperationContract]
  string Ping();
}

把这段代码放在主机程序中

public class WcfPingTest : IWcfPingTest
{
  public const string magicString = "djeut73bch58sb4"; // this is random, just to see if you get the right result
  public string Ping() {return magicString;}
}
public void WcfTestHost_Open()
{
  string hostname = System.Environment.MachineName;
  var baseAddress = new UriBuilder("http", hostname, 7400, "WcfPing");
  var h = new ServiceHost(typeof(WcfPingTest), baseAddress.Uri);

  // enable processing of discovery messages.  use UdpDiscoveryEndpoint to enable listening. use EndpointDiscoveryBehavior for fine control.
  h.Description.Behaviors.Add(new ServiceDiscoveryBehavior());
  h.AddServiceEndpoint(new UdpDiscoveryEndpoint());

  // enable wsdl, so you can use the service from WcfStorm, or other tools.
  var smb = new ServiceMetadataBehavior();
  smb.HttpGetEnabled = true;
  smb.MetadataExporter.PolicyVersion = PolicyVersion.Policy15;
  h.Description.Behaviors.Add(smb);

  // create endpoint
  var binding = new BasicHttpBinding(BasicHttpSecurityMode.None);
  h.AddServiceEndpoint(typeof(IWcfPingTest) , binding,   "");
  h.Open();
  Console.WriteLine("host open");
}

把这段代码放在客户端程序中

private IWcfPingTest channel;
public Uri WcfTestClient_DiscoverChannel()
{
  var dc = new DiscoveryClient(new UdpDiscoveryEndpoint());
  FindCriteria fc = new FindCriteria(typeof(IWcfPingTest));
  fc.Duration = TimeSpan.FromSeconds(5);
  FindResponse fr = dc.Find(fc);
  foreach(EndpointDiscoveryMetadata edm in fr.Endpoints) 
  {
    Console.WriteLine("uri found = " + edm.Address.Uri.ToString());
  }
  // here is the really nasty part
  // i am just returning the first channel, but it may not work.
  // you have to do some logic to decide which uri to use from the discovered uris
  // for example, you may discover "127.0.0.1", but that one is obviously useless.
  // also, catch exceptions when no endpoints are found and try again.
  return fr.Endpoints[0].Address.Uri;  
}
public void WcfTestClient_SetupChannel()
{
  var binding = new BasicHttpBinding(BasicHttpSecurityMode.None);
  var factory = new ChannelFactory<IWcfPingTest>(binding);
  var uri = WcfTestClient_DiscoverChannel();
  Console.WriteLine("creating channel to " + uri.ToString());
  EndpointAddress ea = new EndpointAddress(uri);
  channel = factory.CreateChannel(ea);
  Console.WriteLine("channel created");
  //Console.WriteLine("pinging host");
  //string result = channel.Ping();
  //Console.WriteLine("ping result = " + result);
}
public void WcfTestClient_Ping()
{
  Console.WriteLine("pinging host");
  string result = channel.Ping();
  Console.WriteLine("ping result = " + result);
}

在主机上,只需调用WcfTestHost_Open()函数,然后永远睡眠或其他东西.

在客户端上,运行这些功能.主机打开需要一段时间,因此这里有几个延迟.

System.Threading.Thread.Sleep(8000);
this.server.WcfTestClient_SetupChannel();
System.Threading.Thread.Sleep(2000);
this.server.WcfTestClient_Ping();

主机输出应该是这样的

host open

客户端输出应该是这样的

uri found = http://wilkesvmdev:7400/WcfPing
creating channel to http://wilkesvmdev:7400/WcfPing
channel created
pinging host
ping result = djeut73bch58sb4

对于一个发现例子来说,这是我能想到的最低限度.这些东西变得非常复杂.

Answer 2

该死！这是防火墙的原因...由于某种原因，所有 UDP 通信都被阻止 - 禁用防火墙解决了问题。现在我只需要找出正确的防火墙配置......