Client Configuration

You can use the Windows Communication Foundation (WCF) client configuration to specify the address, binding, behavior, and contract, the "ABC" properties of the client endpoint, which clients use to connect to service endpoints. The <client> element has an <endpoint> element whose attributes are used to configure the endpoint ABCs. These attributes are discussed in the Configuring Endpoints section.

The <endpoint> element also contains a <metadata> element that is used to specify settings for importing and exporting metadata, a <headers> element that contains a collection of custom address headers, and an <identity> element that enables the authentication of an endpoint by other endpoints exchanging messages with it. The <headers> and <identity> elements are part of the EndpointAddress and are discussed in the Addresses article. Links to topics that explain the use of metadata extensions are provided in the Configuring Metadata section.

Configuring Endpoints

The client configuration is designed to allow the client to specify one or more endpoints, each with its own name, address, and contract, with each referencing the <bindings> and <behaviors> elements in the client configuration to be used to configure that endpoint. The client configuration file should be named "App.config" because this is the name that the WCF runtime expects. The following example shows a client configuration file.

<?xml version="1.0" encoding="utf-8"?>  
            contract="IHello" >  
                  type="Microsoft.ServiceModel.Samples.WsdlDocumentationImporter, WsdlDocumentation"/>  
              <servicePrincipalName value="host/localhost" />  
            <!-- Add another endpoint by adding another <endpoint> element. -->
           //Configure another endpoint here.  
<!-- The bindings section references by the bindingConfiguration endpoint attribute.   -->
        <binding name="WSHttpBinding_IHello"
          <readerQuotas maxDepth="32"/>  
          <reliableSession ordered="true"
                           enabled="false" />  
          <security mode="Message">  
           <!-- Security settings go here.   -->
        <binding name="Another Binding"  
          <!-- Configure this binding here. -->  
<!-- The behavior section references by the behaviorConfiguration endpoint attribute.   -->
                <behavior name=" IHello_Behavior ">  
                    <clientVia />  

The optional name attribute uniquely identifies an endpoint for a given contract. It is used by the ChannelFactory<TChannel> or by the ClientBase<TChannel> to specify which endpoint in the client configuration is being targeted and must be loaded when a channel is created to service. A wildcard endpoint configuration name "*" is available and indicates to the ApplyConfiguration method that it should load any endpoint configuration in the file, provided there is precisely one available, and otherwise throws an exception. If this attribute is omitted, the corresponding endpoint is used as the default endpoint associated with the specified contract type. The default value for the name attribute is an empty string which is matched like any other name.

Every endpoint must have an address associated with it to locate and identify the endpoint. The address attribute can be used to specify the URL that provides the location of the endpoint. But the address for a service endpoint can also be specified in code by creating a Uniform Resource Identifier (URI) and is added to the ServiceHost using one of the AddServiceEndpoint methods. For more information, see Addresses. As the introduction indicates, the <headers> and <identity> elements are part of the EndpointAddress and are also discussed in the Addresses topic.

The binding attribute indicates the type of binding the endpoint expects to use when connecting to a service. The type must have a registered configuration section if it is to be referenced. In the previous example, this is the <wsHttpBinding> section, which indicates that the endpoint uses a WSHttpBinding. But there may be more than one binding of a given type that the endpoint can use. Each of these has its own <binding> element within the (binding) type element. The bindingconfiguration attribute is used to distinguish between bindings of the same type. Its value is matched with the name attribute of the <binding> element. For more information about how to configure a client binding using configuration, see How to: Specify a Client Binding in Configuration.

The behaviorConfiguration attribute is used to specify which <behavior> of the <endpointBehaviors> the endpoint should use. Its value is matched with the name attribute of the <behavior> element. For an example of using configuration to specify client behaviors, see Configuring Client Behaviors.

The contract attribute specifies which contract the endpoint is exposing. This value maps to the ConfigurationName of the ServiceContractAttribute. The default value is the full type name of the class that implements the service.

Configuring Metadata

The <metadata> element is used to specify settings used to register metadata import extensions. For more information about extending the metadata system, see Extending the Metadata System.

See also