C# 4 and .NET 4

Hosting ❘ 1303
To abort the service host, you can invoke the Abort() method of the ServiceHost class. To get the current
state of the service, the State property returns a value defi ned by the CommunicationState enumeration.
Possible values are Created , Opening , Opened , Closing , Closed , and Faulted .
If you start the service from within a Windows Forms or WPF application and
the service code invokes methods of Windows controls, you must be sure that
only the control’s creator thread is allowed to access the methods and properties
of the control. With WCF, this behavior can be achieved easily by setting the
UseSynchronizationContext property of the attribute [ServiceBehavior].
Was hosting
With WAS (Windows Activation Services) hosting, you get the features from the WAS worker process such
as automatic activation of the service, health monitoring, and process recycling.
To use WAS hosting, you just need to create a web site and a .svc fi le with the ServiceHost declaration
that includes the language and the name of the service class. The code shown here is using the class
Service1 . In addition, you must specify the fi le that contains the service class. This class is implemented in
the same way that you saw earlier when defi ning a WCF service library.
< %@ServiceHost language="C#" Service="Service1" CodeBehind="Service1.svc.cs" % >
If you use a WCF service library that should be available from WAS hosting, you can create a .svc fi le that
just contains a reference to the class:
< %@ ServiceHost Service="Wrox.ProCSharp.WCF.Services.RoomReservationService" % >
Since the introduction of Windows Vista and Windows Server 2008, WAS allows defi ning .NET TCP and
Message Queue bindings. If you are using the previous edition, IIS 6 or IIS 5.1, which is available with
Windows Server 2003 and Windows XP, activation from a .svc fi le can be done only with an HTTP binding.
You can also add a WCF service to Enterprise Service components. This is discussed in
Chapter 51.
Preconfigured host Classes
To reduce the confi guration necessities, WCF also offers some hosting classes with preconfi gured
bindings. One example is located in the assembly System.ServiceModel.Web in the namespace System
.ServiceModel.Web with the class WebServiceHost . This class creates a default endpoint for HTTP and
HTTPS base addresses if a default endpoint is not confi gured with the WebHttpBinding . Also, this class
adds the WebHttpBehavior if another behavior is not defi ned. With this behavior, simple HTTP GET and
POST , PUT , DELETE (with the WebInvoke attribute) operations can be done without additional setup.
Uri baseAddress = new Uri("http://localhost:8000/RoomReservation");
var host = new WebServiceHost(typeof(RoomReservationService), baseAddress);
host.Open();
Console.WriteLine("service running");
Console.WriteLine("Press return to exit...");
Console.ReadLine();
if (host.State == CommunicationState.Opened)
host.Close();
code snippet RoomReservationWebServiceHost/Program.cs
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