PolicyConversionContext Class

Defines a class used to retrieve binding assertions in metadata and to attach implementing binding elements at the appropriate scope.

Namespace:  System.ServiceModel.Description
Assembly:  System.ServiceModel (in System.ServiceModel.dll)

public abstract class PolicyConversionContext

An implementation of the PolicyConversionContext is passed to IPolicyExportExtension and IPolicyImportExtension objects to export and import, respectively, custom policy assertions to and from metadata. On export, a collection of policy assertions are retrieved in order to add custom assertions. On import, the assertions are retrieved in order to import specific ones and configure binding elements appropriately.

The following code example shows an implementation of the ImportPolicy method that writes all policy assertions to the console. The code comments describe how to locate a specific custom policy assertion, create and insert an implementing binding element, and remove the assertion from the collection.

public void ImportPolicy(MetadataImporter importer, 
    PolicyConversionContext context)
{
    Console.WriteLine("The custom policy importer has been called.");
    foreach (XmlElement assertion in context.GetBindingAssertions())
    {
        Console.WriteLine(assertion.NamespaceURI + " : " + assertion.Name);
        // locate a particular assertion by Name and NamespaceURI
        XmlElement customAssertion = context.GetBindingAssertions().Find(name1, ns1);
        if (customAssertion != null)
        {
          // Found assertion; remove from collection.
          context.GetBindingAssertions().Remove(customAssertion);
          Console.WriteLine(
            "Removed our custom assertion from the imported "
            + "assertions collection and inserting our custom binding element."
          );
            // Here if you find the custom policy assertion that you are looking for, 
            // add the custom binding element that handles the functionality that the policy indicates. 
            // Attach it to the PolicyConversionContext.BindingElements collection. 
            // For example, if the custom policy had a "speed" attribute value:
            /*
              string speed 
                = customAssertion.GetAttribute(SpeedBindingElement.name2, SpeedBindingElement.ns2);
              SpeedBindingElement e = new SpeedBindingElement(speed);
              context.BindingElements.Add(e);
            */
        }

        // write assertion name in red.
        Console.ForegroundColor = ConsoleColor.Red;
        Console.WriteLine(assertion.NamespaceURI + " : " + assertion.Name);

        //write contents in gray.
        Console.WriteLine(assertion.OuterXml);
        Console.ForegroundColor = ConsoleColor.Gray; 
    }
}

The following code example shows how to register IPolicyImportExtension implementations using the <policyImporters> configuration section.

<configuration>
  <system.serviceModel>
    <client>
      <metadata>
        <policyImporters>
          <extension type="CustomPolicyImporter, assembly"/>
        </policyImporters>
      </metadata>
    </client>
  </system.serviceModel>
</configuration>

The following code example demonstrates how a custom binding element can implement IPolicyExportExtension to attach a custom policy assertion to the binding assertions.

	public class MyBindingElement : BindingElement, IPolicyExportExtension
	{
	// BindingElement implementation . . . 

		public void ExportPolicy(
		 MetadataExporter exporter, PolicyConversionContext context)
		{
			XmlDocument xmlDoc = new XmlDocument();
			XmlElement xmlElement = 
			       xmlDoc.CreateElement("MyPolicyAssertion");
			context.GetBindingAssertions().Add(xmlElement);
		}


		// Note: All custom binding elements must return a deep clone  
		// to enable the run time to support multiple bindings using the  
		// same custom binding. 
		public override BindingElement Clone()
		{
			// this is just a placeholder 
			return null;
		}


		// Call the inner property. 
		public override T GetProperty<T>(BindingContext context)
		{
			return context.GetInnerProperty<T>();
		}

	}

	public class Program {
		public static void Main(string[] args) {
			EndpointAddress address = 
				new EndpointAddress("http://localhost/metadata");
			CustomBinding customBinding = 
				new CustomBinding(new BasicHttpBinding());
			customBinding.Elements.Add(new MyBindingElement());
			ContractDescription contract =
				ContractDescription.GetContract(typeof(MyContract));
			ServiceEndpoint endpoint = 
				new ServiceEndpoint(contract, customBinding, address);
			MetadataExporter exporter = new WsdlExporter();
			exporter.ExportEndpoint(endpoint);
		}
	}

System.Object
  System.ServiceModel.Description.PolicyConversionContext

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0
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