PolicyConversionContext.GetBindingAssertions 方法

定义

命名空间:

System.ServiceModel.Description

程序集:

System.ServiceModel.dll

从元数据获取策略断言的集合。

public:
 abstract System::ServiceModel::Description::PolicyAssertionCollection ^ GetBindingAssertions();

public abstract System.ServiceModel.Description.PolicyAssertionCollection GetBindingAssertions ();

abstract member GetBindingAssertions : unit -> System.ServiceModel.Description.PolicyAssertionCollection

Public MustOverride Function GetBindingAssertions () As PolicyAssertionCollection

返回

PolicyAssertionCollection

一个包含绑定策略断言的类型为 ICollection<T> 的 XmlElement。

示例

下面的代码示例演示了 ImportPolicy 方法的实现，该方法将所有策略断言写入了控制台。 代码注释说明了如何查找特定的自定义策略断言，如何创建和插入实现绑定元素，以及如何从集合中移除断言。

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;
    }
}

下面的代码示例演示了如何使用 IPolicyImportExtension 配置节来注册 <policyImporters> 实现。

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

下面的代码示例演示了自定义绑定元素是如何实现 IPolicyExportExtension 的，以便将自定义策略断言附加到绑定断言。

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);
    }
}

注解

从 GetBindingAssertions 返回的集合不是副本。 您可以在必要时添加和移除断言。