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MetadataImporter Class

Imports metadata into System.ServiceModel.Description::ServiceEndpoint objects.

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

public ref class MetadataImporter abstract

Use an implementation of the MetadataImporter abstract class to import service metadata. Types that derive from the MetadataImporter class implement support for importing metadata formats that take advantage of the WS-Policy import logic in Windows Communication Foundation (WCF).

A MetadataImporter implementation collects the policy expressions attached to the service metadata in a System.ServiceModel.Description::PolicyConversionContext object. The MetadataImporter then processes the policies as part of importing the metadata by calling the implementations of the System.ServiceModel.Description::IPolicyImportExtension interface in the MetadataImporter::PolicyImportExtensions property.

You can add support for importing new policy assertions to a MetadataImporter by adding your own implementation of the System.ServiceModel.Description::IPolicyImportExtension interface to the MetadataImporter::PolicyImportExtensions property on a MetadataImporter instance. Alternatively, you can register your policy import extension in your application configuration file.

The System.ServiceModel.Description::WsdlImporter type is the implementation of the MetadataImporter abstract class included with WCF. The System.ServiceModel.Description::WsdlImporter type imports WSDL metadata with attached policies that are bundled in a System.ServiceModel.Description::MetadataSet object.

You can add support for importing WSDL extensions by implementing the System.ServiceModel.Description::IWsdlImportExtension interface and then adding your implementation to the WsdlImporter::WsdlImportExtensions property on your System.ServiceModel.Description::WsdlImporter instance. The System.ServiceModel.Description::WsdlImporter can also load implementations of the System.ServiceModel.Description::IWsdlImportExtension interface registered in your application configuration file.


Because the MetadataImporter constructor is internal, you cannot derive from MetadataImporter in this version.

The following example shows the use of the System.ServiceModel.Description::WsdlImporter derived class to import metadata using custom state, checking the Errors property, compiling imported metadata to managed types and saving the result to a code file.

		static void GenerateCSCodeForService(EndpointAddress metadataAddress, string outputFile)
      MetadataExchangeClient mexClient = new MetadataExchangeClient(metadataAddress);
      mexClient.ResolveMetadataReferences = true;
      MetadataSet metaDocs = mexClient.GetMetadata();

			WsdlImporter importer = new WsdlImporter(metaDocs);
      ServiceContractGenerator generator = new ServiceContractGenerator();

      // Add our custom DCAnnotationSurrogate  
      // to write XSD annotations into the comments.
      object dataContractImporter;
      XsdDataContractImporter xsdDCImporter;
      if (!importer.State.TryGetValue(typeof(XsdDataContractImporter), out dataContractImporter))
        Console.WriteLine("Couldn't find the XsdDataContractImporter! Adding custom importer.");
        xsdDCImporter = new XsdDataContractImporter();
        xsdDCImporter.Options = new ImportOptions();
        importer.State.Add(typeof(XsdDataContractImporter), xsdDCImporter);
        xsdDCImporter = (XsdDataContractImporter)dataContractImporter;
        if (xsdDCImporter.Options == null)
          Console.WriteLine("There were no ImportOptions on the importer.");
          xsdDCImporter.Options = new ImportOptions();
      xsdDCImporter.Options.DataContractSurrogate = new DCAnnotationSurrogate();

      // Uncomment the following code if you are going to do your work programmatically rather than add  
      // the WsdlDocumentationImporters through a configuration file.  
      // The following code inserts a custom WsdlImporter without removing the other 
      // importers already in the collection.
      System.Collections.Generic.IEnumerable<IWsdlImportExtension> exts = importer.WsdlImportExtensions;
      System.Collections.Generic.List<IWsdlImportExtension> newExts 
        = new System.Collections.Generic.List<IWsdlImportExtension>();
      foreach (IWsdlImportExtension ext in exts)
        Console.WriteLine("Default WSDL import extensions: {0}", ext.GetType().Name);
      newExts.Add(new WsdlDocumentationImporter());
      System.Collections.Generic.IEnumerable<IPolicyImportExtension> polExts = importer.PolicyImportExtensions;
      importer = new WsdlImporter(metaDocs, polExts, newExts);

      System.Collections.ObjectModel.Collection<ContractDescription> contracts 
        = importer.ImportAllContracts();
			foreach (ContractDescription contract in contracts)
      if (generator.Errors.Count != 0)
        throw new Exception("There were errors during code compilation.");

      // Write the code dom
      System.CodeDom.Compiler.CodeGeneratorOptions options 
        = new System.CodeDom.Compiler.CodeGeneratorOptions();
			options.BracingStyle = "C";
			System.CodeDom.Compiler.CodeDomProvider codeDomProvider 
        = System.CodeDom.Compiler.CodeDomProvider.CreateProvider("C#");
			System.CodeDom.Compiler.IndentedTextWriter textWriter 
        = new System.CodeDom.Compiler.IndentedTextWriter(new System.IO.StreamWriter(outputFile));
        generator.TargetCompileUnit, textWriter, options


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