我正在使用一个 Windows 服务,我也想在其中添加一个 GUI。我通过我的服务创建了一个 ServiceHost 对象并托管 WCF 命名管道服务,然后我使用控制台应用程序来使用 WCF 服务并从服务获取回调响应(从服务器发送到连接的客户端的消息),进行了概念验证。这很好用,我的控制台应用程序运行并从服务中获得响应,没有中断或延迟。
但是,当在我的 WPF GUI 应用程序中做同样的事情时,当单击一个按钮然后调用 WCF 服务时,它会冻结整个 UI 线程,然后在几分钟后引发异常,然后使用消息回调更新 UI(服务器发送消息到连接的客户端),但由于抛出异常,服务的任何返回值都将丢失。
我得到的两个异常消息是论文(最常见的是第一个):
1:发送到net.pipe://localhost/PipeGUI的请求动作在指定的超时时间(00:00:59.9989999)内没有收到响应。分配给此操作的时间可能是较长超时的一部分。这可能是因为服务仍在处理操作,或者因为服务无法发送回复消息。提高操作的截止日期(通过输入通道/代理到图标文本通道并设置属性操作超时)并验证服务可以连接到客户端。
2:通讯对象System.ServiceModel.Channels.ServiceChannel,因为已经取消,不能用于通讯。
有人知道为什么会这样吗?如有必要,我可以发布更多代码。
更新,添加代码供参考
public interface IClientCallback
{
[OperationContract(IsOneWay = true)]
void MessageRecived(string message);
}
[ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(IClientCallback))]
public interface IPipeServiceContract
{
[OperationContract]
string Hello();
[OperationContract]
void Message(string msg);
[OperationContract(IsInitiating = true)]
void Connect();
[OperationContract(IsTerminating = true)]
void Disconnect();
}
[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, IncludeExceptionDetailInFaults = true, UseSynchronizationContext = false)]
public class PipeService : IPipeServiceContract
{
List<IClientCallback> _clients = new List<IClientCallback>();
public string Hello()
{
PublishMessage("Hello World.");
return "Return from method!";
}
public void Connect()
{
_clients.Add(OperationContext.Current.GetCallbackChannel<IClientCallback>());
}
public void Disconnect()
{
IClientCallback callback = OperationContext.Current.GetCallbackChannel<IClientCallback>();
_clients.Remove(callback);
}
void PublishMessage(string message)
{
for (int i = _clients.Count - 1; i > 0; i--)
{
try
{
_clients[i].MessageRecived(message);
}
catch (CommunicationObjectAbortedException coae)
{
_clients.RemoveAt(i);
}
catch(CommunicationObjectFaultedException cofe)
{
_clients.RemoveAt(i);
}
}
}
public void Message(string msg)
{
PublishMessage(msg);
}
}
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window, INotifyPropertyChanged, IClientCallback
{
public ServiceController Service { get; set; }
protected IPipeServiceContract Proxy { get; set; }
protected DuplexChannelFactory<IPipeServiceContract> PipeFactory { get; set; }
public ObservableCollection<ServerActivityNotification> Activity { get; set; }
public override void BeginInit()
{
base.BeginInit();
PipeFactory = new DuplexChannelFactory<IPipeServiceContract>(this, new NetNamedPipeBinding(), new EndpointAddress("net.pipe://localhost/PipeGUI"));
}
public MainWindow()
{
InitializeComponent();
Activity = new ObservableCollection<ServerActivityNotification>();
Service = ServiceController.GetServices().First(x => x.ServiceName == "Server Service");
NotifyPropertyChanged("Service");
var timer = new DispatcherTimer();
timer.Tick += new EventHandler(OnUpdate);
timer.Interval = new TimeSpan(0, 0, 0, 0, 850);
timer.Start();
if (Service.Status == ServiceControllerStatus.Running)
{
Proxy = PipeFactory.CreateChannel();
Proxy.Connect();
}
}
void OnUpdate(object sender, EventArgs e)
{
Service.Refresh();
NotifyPropertyChanged("Service");
StartButton.IsEnabled = Service.Status != ServiceControllerStatus.Running ? true : false;
StopButton.IsEnabled = Service.Status != ServiceControllerStatus.Stopped ? true : false;
if (PipeFactory != null && Service.Status == ServiceControllerStatus.Running)
{
Proxy = PipeFactory.CreateChannel();
Proxy.Connect();
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string name)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(name));
}
private void OnStart(object sender, RoutedEventArgs e)
{
try
{
Service.Start();
}
catch
{
Service.Refresh();
}
}
private void OnStop(object sender, RoutedEventArgs e)
{
try
{
if (Proxy != null)
{
Proxy.Disconnect();
PipeFactory.Close();
}
Service.Stop();
}
catch
{
Service.Refresh();
}
}
public void MessageRecived(string message)
{
Dispatcher.BeginInvoke(DispatcherPriority.Background, new Action(() =>
{
ServerActivityNotification log = new ServerActivityNotification { Activity = message, Occured = DateTime.Now };
Activity.Add(log);
ListBoxLog.ScrollIntoView(log);
NotifyPropertyChanged("Activity");
}));
}
private void OnHello(object sender, RoutedEventArgs e)
{
try
{
Proxy.Message(txtSendMessage.Text);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
}
}