[英]TimeOut exception in WCF while implementing duplex
我的服務合同和回調合同如下所示:
[ServiceContract(CallbackContract = typeof(IWebshopCallback))]
interface IWebshop
{
[OperationContract]
string GetWebshopName ();
[OperationContract]
string GetProductInfo (Item i);
[OperationContract]
List<Item> GetProductList ();
[OperationContract]
bool BuyProduct (string i);
[OperationContract]
void ConnectNewClient ();
}
[ServiceContract]
interface IWebshopCallback
{
[OperationContract]
void NewClientConnected (int totalNrOfConnectedClients);
}
我的服務:
[ServiceBehavior (InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Reentrant)]
class WebshopService : IWebshop
{
...
}
在服務內部,我有一個方法可以在客戶端調用另一個方法:
public void ConnectNewClient ()
{
totalNumber++;
OperationContext.Current.GetCallbackChannel<IWebshopCallback> ().NewClientConnected (totalNumber);
}
在客戶端,我有一個從IWebshopCallback派生並具有方法NewClientConnected(int a)的表單。
問題是,當我嘗試運行代碼時,遇到了以下異常:
發送到http:// localhost:4000 / IWebshopContract的此請求操作在配置的超時時間(00:00:59.9989895)內未收到答復。 分配給該操作的時間可能是較長超時的一部分。
但是,更奇怪的是,如果我繼續應用程序的工作,我會看到此功能有效。
是什么原因造成的呢?
在服務器端,當您調用一個函數時,您需要使用Task.Run(),因此您應該像這樣:
var callback = OperationContext.Current.GetCallbackChannel<IWebshopCallback> ();
Task.Run (() => callback.NewClientConnected(totalNumber));
而不是這樣:
OperationContext.Current.GetCallbackChannel<IWebshopCallback> ().NewClientConnected ();
通常,除雙工模式外,我們的行為是客戶端在調用服務后立即返回,並且服務器發送回的信息通過回調合同進行傳輸。 在這種工作模式下,我們將服務合同和回調合同都轉換為單向通信。
[OperationContract(Action = "post_num", IsOneWay = true)]
void PostNumber(int n);
我做了一個演示,希望對您有用。
服務器端。
class Program
{
static void Main(string[] args)
{
using (ServiceHost sh=new ServiceHost(typeof(MyService)))
{
ServiceMetadataBehavior smb;
smb = sh.Description.Behaviors.Find<ServiceMetadataBehavior>();
if (smb==null)
{
smb = new ServiceMetadataBehavior()
{
HttpGetEnabled = true
};
sh.Description.Behaviors.Add(smb);
}
sh.Open();
Console.WriteLine("Service is ready");
Console.ReadKey();
sh.Close();
}
}
}
[ServiceContract(Namespace ="mydomain",Name = "demo", ConfigurationName = "isv", CallbackContract = typeof(ICallback))]
public interface IDemo
{
[OperationContract(Action = "post_num", IsOneWay = true)]
void PostNumber(int n);
}
[ServiceContract]
public interface ICallback
{
[OperationContract(Action = "report", IsOneWay = true)]
void Report(double progress);
}
[ServiceBehavior(ConfigurationName ="sv")]
public class MyService : IDemo
{
public void PostNumber(int n)
{
ICallback callback = OperationContext.Current.GetCallbackChannel<ICallback>();
for (int i = 0; i <=n; i++)
{
Task.Delay(500).Wait();
double p = Convert.ToDouble(i) / Convert.ToDouble(n);
callback.Report(p);
}
}
}
服務器配置
<system.serviceModel>
<services>
<service name="sv">
<endpoint address="http://localhost:3333" binding="wsDualHttpBinding" contract="isv"/>
<host>
<baseAddresses>
<add baseAddress="http://localhost:3333"/>
</baseAddresses>
</host>
</service>
</services>
</system.serviceModel>
客戶端。
class Program
{
static void Main(string[] args)
{
DuplexChannelFactory<IDemo> factory = new DuplexChannelFactory<IDemo>(new CallbackHandler(), "test_ep");
IDemo channel = factory.CreateChannel();
Console.WriteLine("Start to Call");
channel.PostNumber(15);
Console.WriteLine("Calling is done");
Console.ReadLine();
}
}
[ServiceContract(Namespace ="mydomain",Name = "demo", ConfigurationName = "isv", CallbackContract = typeof(ICallback))]
public interface IDemo
{
[OperationContract(Action = "post_num",IsOneWay =true)]
void PostNumber(int n);
}
[ServiceContract]
public interface ICallback
{
[OperationContract(Action = "report",IsOneWay =true)]
void Report(double progress);
}
public class CallbackHandler : ICallback
{
public void Report(double progress)
{
Console.WriteLine("{0:p0}", progress);
}
}
客戶端配置
<system.serviceModel>
<client>
<endpoint name="test_ep" address="http://localhost:3333" binding="wsDualHttpBinding" contract="isv"/>
</client>
</system.serviceModel>
結果。
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