WCF and Bindings - Binding configuration
(Page 3 of 4 )
You can use the config file to customize the binding used by the endpoint. To that end, add the bindingConfiguration tag to the endpoint section, and name a customized section in thebindingssection of the config file. Example 1-8 demonstrates using this technique to enable transaction propagation. What thetransactionFlowtag does will be explained in Chapter 7.
Example 1-8. Service-side binding configuration
<system.serviceModel>
<services>
<service name = "MyService">
<endpoint
address = "net.tcp://localhost:8000/MyService/"
bindingConfiguration = "TransactionalTCP"
binding = "netTcpBinding"
contract = "IMyContract"
/>
<endpoint
address = "net.tcp://localhost:8001/MyService/"
bindingConfiguration = "TransactionalTCP"
binding = "netTcpBinding"
contract = "IMyOtherContract"
/>
</service>
</services>
<bindings>
<netTcpBinding>
<binding name = "TransactionalTCP"
transactionFlow = "true"
/>
</netTcpBinding>
</bindings>
</system.serviceModel>
As shown in Example 1-8, you can reuse the named binding configuration in multiple endpoints simply by referring to it.
Programmatic Endpoint Configuration
Programmatic endpoint configuration is equivalent to administrative configuration. Instead of resorting to a config file, you rely on programmatic calls to add endpoints to the ServiceHost instance. Again, these calls are always outside the scope of the service code. ServiceHost provides overloaded versions of theAddServiceEndpoint()method:
public class ServiceHost : ServiceHostBas
{
public ServiceEndpoint AddServiceEndpoint(Type implementedContract,
Binding binding,
string address);
//Additional members
}
You can provideAddServiceEndpoint()methods with either relative or absolute addresses, just as with a config file. Example 1-9 demonstrates programmatic configuration of the same endpoints as in Example 1-7.
Example 1-9. Service-side programmatic endpoint configuration
ServiceHost host = new ServiceHost(typeof(MyService));
Binding wsBinding = new WSHttpBinding(); Binding tcpBinding = new NetTcpBinding();
host.AddServiceEndpoint(typeof(IMyContract),wsBinding,
"http://localhost:8000/MyService"); host.AddServiceEndpoint(typeof(IMyContract),tcpBinding,
"net.tcp://localhost:8001/MyService"); host.AddServiceEndpoint(typeof(IMyOtherContract),tcpBinding,
"net.tcp://localhost:8002/MyService");
host.Open();
When you add an endpoint programmatically, the address is given as a string, the contract as aType, and the binding as one of the subclasses of the abstract classBinding, such as:
public class NetTcpBinding : Binding,...
{...}
To rely on the host base address, provide an empty string if you want to use the base address, or just the URI to use the base address plus the URI:
Uri tcpBaseAddress = new Uri("net.tcp://localhost:8000/");
ServiceHost host = new ServiceHost(typeof(MyService),tcpBaseAddress);
Binding tcpBinding = new NetTcpBinding();
//Use base address as address
host.AddServiceEndpoint(typeof(IMyContract),tcpBinding,"");
//Add relative address
host.AddServiceEndpoint(typeof(IMyContract),tcpBinding,"MyService");
//Ignore base address
host.AddServiceEndpoint(typeof(IMyContract),tcpBinding,
"net.tcp://localhost:8001/MyService");
host.Open();
As with administrative configuration using a config file, the host must provide a matching base address; otherwise, an exception occurs. In fact, there is no difference between programmatic and administrative configuration. When you use a config file, all WCF does is parse the file and execute the appropriate programmatic calls in its place.
You can programmatically set the properties of the binding used. For example, here is the code required to enable transaction propagation similar to Example 1-8:
ServiceHost host = new ServiceHost(typeof(MyService));
NetTcpBinding tcpBinding = new NetTcpBinding();
tcpBinding.TransactionFlow = true;
host.AddServiceEndpoint(typeof(IMyContract),tcpBinding,
"net.tcp://localhost:8000/MyService");
host.Open();
Note that when you’re dealing with specific binding properties, you typically interact with a concrete binding subclass such asNetTcpBinding, and not its abstract base classBindingas in Example 1-9.
Next: Metadata Exchange >>
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 This article is excerpted from chapter one of Programming WCF Services, written by Juval Lowry (O'Reilly, 2007; ISBN: 0596526997). Check it out at your favorite bookstore. Buy this book now.
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