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DiscoveryClientProtocol.Discover Method

Discovers the supplied URL to determine if it is a discovery document.

Namespace: System.Web.Services.Discovery
Assembly: System.Web.Services (in

public DiscoveryDocument Discover (
	string url
public DiscoveryDocument Discover (
	String url
public function Discover (
	url : String
) : DiscoveryDocument
Not applicable.



The URL where XML Web services discovery begins.

Return Value

A DiscoveryDocument containing the results of XML Web services discovery at the supplied URL.

Exception typeCondition


Accessing the supplied URL returned an HTTP status code other than OK.


The url parameteris a valid URL, but does not point to a valid discovery document.

The Discover method expects that the supplied URL is a discovery document. If the URL refers to a service description or an XML schema an exception is thrown. To discover an XML schema or a service description invoke the DiscoverAny method.

If the supplied URL points to a valid discovery document, the discovery document at the supplied URL is added to the Documents and References collection. Additionally, references within the discovery document are added to the References collection, but not verified to point to valid discovery documents. To verify the references, point to valid discovery documents to invoke the ResolveAll or ResolveOneLevel methods.

The following code example is a Web Form that populates a DataGrid with the details about the documents in the Documents property together with the references found in each document during XML Web services discovery. The PopulateGrid method fills the DataGrid with the results from a Discover invocation followed by a call to ResolveAll.

 protected void Discover_Click(object Source, EventArgs e)
  // Specify the URL to discover.
  string sourceUrl = DiscoURL.Text;
  // Specify the URL to save discovery results to or read from.
  string outputDirectory = DiscoDir.Text;

      DiscoveryClientProtocol client = new DiscoveryClientProtocol();
  // Use default credentials to access the URL being discovered.
      client.Credentials = CredentialCache.DefaultCredentials;

           DiscoveryDocument doc;
        // Only discover discovery documents, which might contain references to other types of discoverable documents.  
    doc = client.Discover(sourceUrl);
        // Resolve all possible references from the supplied URL.
      catch ( Exception e2) 
        Status.Text = e2.Message;
  // If documents were discovered, display the results in a data grid.
      if (client.Documents.Count > 0)

  // Save the discovery results to disk.
      DiscoveryClientResultCollection results = client.WriteAll(outputDirectory, "results.discomap");
      Status.Text = "The following file holds the links to each of the discovery results: <b>" + 
                                  Path.Combine(outputDirectory,"results.discomap") + "</b>";

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0