DiscoveryClientProtocol Class


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Provides support for programmatically invoking XML Web services discovery.

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


Public Class DiscoveryClientProtocol
	Inherits HttpWebClientProtocol


Initializes a new instance of the DiscoveryClientProtocol class.


Gets information in addition to references found in the discovery document.


Gets or sets whether the client automatically follows server redirects.(Inherited from HttpWebClientProtocol.)


Gets a value indicating whether the component can raise an event.(Inherited from Component.)


Gets the collection of client certificates.(Inherited from HttpWebClientProtocol.)


Gets or sets the name of the connection group for the request.(Inherited from WebClientProtocol.)


Gets the IContainer that contains the Component.(Inherited from Component.)


Gets or sets the collection of cookies.(Inherited from HttpWebClientProtocol.)


Gets or sets security credentials for XML Web service client authentication.(Inherited from WebClientProtocol.)


Gets a value that indicates whether the Component is currently in design mode.(Inherited from Component.)


Gets a collection of discovery documents.


Gets or sets a value that indicates whether decompression is enabled for this HttpWebClientProtocol. (Inherited from HttpWebClientProtocol.)


Gets a collection of exceptions that occurred during invocation of method from this class.


Gets the list of event handlers that are attached to this Component.(Inherited from Component.)


Gets or sets whether pre-authentication is enabled.(Inherited from WebClientProtocol.)


Gets or sets proxy information for making an XML Web service request through a firewall.(Inherited from HttpWebClientProtocol.)


A collection of references founds in resolved discovery documents.


The Encoding used to make the client request to the XML Web service.(Inherited from WebClientProtocol.)


Gets or sets the ISite of the Component.(Inherited from Component.)


Indicates the time an XML Web service client waits for the reply to a synchronous XML Web service request to arrive (in milliseconds).(Inherited from WebClientProtocol.)


Gets or sets a value that indicates whether connection sharing is enabled when the client uses NTLM authentication to connect to the Web server that hosts the XML Web service.(Inherited from HttpWebClientProtocol.)


Gets or sets the base URL of the XML Web service the client is requesting.(Inherited from WebClientProtocol.)


Gets or sets a value that indicates whether to set the Credentials property to the value of the CredentialCache.DefaultCredentials property.(Inherited from WebClientProtocol.)


Gets or sets the value for the user agent header that is sent with each request.(Inherited from HttpWebClientProtocol.)


Cancels a request to an XML Web service method.(Inherited from WebClientProtocol.)


Cancels an asynchronous call to an XML Web service method, unless the call has already completed.(Inherited from HttpWebClientProtocol.)


Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.(Inherited from MarshalByRefObject.)


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


Discovers the supplied URL to determine if it is a discovery document, service description or an XML Schema Definition (XSD) schema.


Releases all resources used by the Component.(Inherited from Component.)


Releases the unmanaged resources used by the Component and optionally releases the managed resources.(Inherited from Component.)


Downloads the discovery document at the supplied URL into a Stream object.

System_CAPS_pubmethodDownload(String, String)

Downloads the discovery document at the supplied URL into a Stream object, setting the contentType parameter to the MIME encoding of the discovery document.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Releases unmanaged resources and performs other cleanup operations before the Component is reclaimed by garbage collection.(Inherited from Component.)


Serves as the default hash function. (Inherited from Object.)


Retrieves the current lifetime service object that controls the lifetime policy for this instance.(Inherited from MarshalByRefObject.)


Returns an object that represents a service provided by the Component or by its Container.(Inherited from Component.)


Gets the Type of the current instance.(Inherited from Object.)


Creates a WebRequest for the specified URI.(Inherited from HttpWebClientProtocol.)


Returns a response from a synchronous request to an XML Web service method.(Inherited from HttpWebClientProtocol.)

System_CAPS_protmethodGetWebResponse(WebRequest, IAsyncResult)

Returns a response from an asynchronous request to an XML Web service method.(Inherited from HttpWebClientProtocol.)


Obtains a lifetime service object to control the lifetime policy for this instance.(Inherited from MarshalByRefObject.)


Obsolete. Instructs the DiscoveryClientProtocol object to load any external references.


Creates a shallow copy of the current Object.(Inherited from Object.)


Creates a shallow copy of the current MarshalByRefObject object.(Inherited from MarshalByRefObject.)


Reads in a file containing a map of saved discovery documents populating the Documents and References properties, with discovery documents, XML Schema Definition (XSD) schemas, and service descriptions referenced in the file.


Resolves all references to discovery documents, XML Schema Definition (XSD) schemas, and service descriptions in the References property, as well as references found in referenced discovery documents.


Resolves all references to discovery documents, XML Schema Definition (XSD) schemas and service descriptions in References, as well as references found in those discovery documents.


Returns a String containing the name of the Component, if any. This method should not be overridden.(Inherited from Component.)

System_CAPS_pubmethodWriteAll(String, String)

Writes all discovery documents, XML Schema Definition (XSD) schemas, and Service Descriptions in the Documents property to the supplied directory and creates a file in that directory.


Occurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)

XML Web service discovery is the process of locating, or discovering, one or more related documents that describe available XML Web services. It is through XML Web services discovery that XML Web service clients learn about the available XML Web services at a given URL and how to use them. XML Web services discovery works from the premise that you have already obtained the URL to a discovery document, possibly through a directory service, such as, however, you do not have the details about the XML Web services offered. Through XML Web services discovery, you can discover the details about the XML Web services listed in a DiscoveryDocument at a specific URL.

An XML Web service client starts XML Web services discovery by supplying a URL to either the Discover or DiscoverAny methods. Typically, this URL refers to a discovery document, which in turn refers to documents that describe one or more XML Web services, which are added to the References property. At that point, only that document is downloaded and verified to point to valid information about XML Web services. However, the references contained in that document are not verified at this stage. Instead they are added to the References property. To verify that the references are valid, invoke the ResolveAll or ResolveOneLevel methods, which add valid referenced documents to the Documents property. Last, if a client wants to save the discovery results to disk, invoke the WriteAll method.

If programmatic access to XML Web services discovery is not needed, the Windows Software Development Kit (SDK) ships the Web Services Discovery tool (Disco.exe) for discovering XML Web services within a command prompt. For more details, see Web Services Discovery Tool (Disco.exe).

The following code example is a Web Form demonstrating how to use the DiscoveryClientProtocol class together with the other classes in the System.Web.Services.Discovery namespace to programmatically invoke XML Web services discovery. The code example demonstrates using the Discover, DiscoverAny, Discover, ResolveAll, ResolveOneLevel, ReadAll and WriteAll methods.

System_CAPS_security Security Note

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

<%@ Page Language="VB" Debug="true" %>

<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Web.Services.Discovery" %>
<%@ Import Namespace="System.Net" %>
<%@ Import Namespace="System.Data" %>

   Public Sub Discover_Click(Source As Object, e as EventArgs )
      ' Specify the URL to discover.
      Dim sourceUrl as String = DiscoURL.Text
      ' Specify the URL to save discovery results to or read from.
      Dim outputDirectory As String = DiscoDir.Text

      Dim client as DiscoveryClientProtocol = new DiscoveryClientProtocol()
      ' Use default credentials to access the URL being discovered.
      client.Credentials = CredentialCache.DefaultCredentials
       	Dim doc As DiscoveryDocument
        ' Check to see whether the user wanted to read in existing discovery results.
	If (DiscoverMode.Value = "ReadAll") Then
	   Dim results As DiscoveryClientResultCollection 
           results = client.ReadAll(Path.Combine(DiscoDir.Text,"results.discomap"))
	   SaveMode.Value = "NoSave"						
	   ' Check to see whether the user user wants the capability to discover any kind of discoverable document.
           If (DiscoverMode.Value = "DiscoverAny") Then
	     doc = client.DiscoverAny(sourceUrl)
	     ' Discover only discovery documents, which might contain references to other types of discoverable documents. 
   	     doc = client.Discover(sourceUrl)
	   End If

           ' Check to see whether the user wants to resolve all possible references from the supplied URL.
 	   If (ResolveMode.Value = "ResolveAll") Then
           ' Check to see whether the user wants to resolve references nested more than one level deep.
	   ElseIf (ResolveMode.Value = "ResolveOneLevel")  Then
  	      Status.Text = String.Empty
           End If
	End If

       Catch e2 As Exception
          Status.Text = e2.Message
       End Try

       ' If documents were discovered, display the results in a data grid.
       If (client.Documents.Count > 0) Then
            'populate our Grid with the discovery results.
       End If

       ' If the user also asked to have the results saved to the Web server, do so.	    
       If (SaveMode.Value = "Save") Then
	  Dim results As 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>"
       End If                             

      End Sub
      Public Sub PopulateGrid(client As DiscoveryClientProtocol) 
         Dim dt As DataTable = new DataTable()
         Dim dr AS DataRow 

         dt.Columns.Add(new DataColumn("Discovery Document") )
         dt.Columns.Add(new DataColumn("References") )
         dt.Columns.Add(new DataColumn("Type") )

	 Dim entry As DictionaryEntry
         For Each entry in client.Documents
            dr = dt.NewRow()
 	    dr(0) = entry.Key
 	    dr(2) = entry.Value.GetType()
	    If TypeOf entry.Value Is DiscoveryDocument Then
	       Dim discoDoc As DiscoveryDocument = entry.Value
	       Dim discoref As DiscoveryReference
	       For Each discoref in discoDoc.References
		  dr = dt.NewRow()
		  dr(1) = discoref.Url
		  dr(2) = discoref.GetType()
	    End If   

        Dim dv As DataView = new DataView(dt)
	DiscoveryResultsGrid.DataSource = dv
     End Sub
	<H3> <p align="center"> Discovery Class Sample </p> </H3>

        Enter the URL to discover:
        <asp:textbox id=DiscoURL Columns=60 runat="SERVER" /><p>

       Discovery Mode:
       <select id="DiscoverMode" size=1 runat="SERVER">
	     <option Value="DiscoverAny">Discover any of the discovery types</option>
             <option Value="Discover">Discover just discovery documents</option>
             <option Value="ReadAll">Read in saved discovery results</option>
	</select> <p>

       Resolve References Mode:
       <select id="ResolveMode" size=1 runat="SERVER">
	      <option Value="ResolveAll">Resolve all references</option>
             <option Value="ResolveOneLevel">Resolve references only in discovery documents within the supplied URL</option>
             <option Value="ResolveNone">Do not resolve references</option>
	</select> <p>

       Save Results Mode:
	<select id="SaveMode" size=1 runat="SERVER">
	      <option Value="NoSave">Do not save any of the discovery documents found locally</option>
             <option Value="Save">Save the discovery documents found locally</option>
      	</select> <p>
        Enter the directory to Read/Save the Discovery results:
        <asp:textbox id=DiscoDir runat="SERVER" /> <p>

	<p align="center"> <asp:Button id=Discover Text="Discover!" onClick="Discover_Click" runat="SERVER"/> </p><p>

        <asp:label id="Status" runat="SERVER" /><p>
     <asp:DataGrid id="DiscoveryResultsGrid"

         <HeaderStyle BackColor="DarkBlue" ForeColor="White">

         <AlternatingItemStyle BackColor="LightYellow">


.NET Framework
Available since 1.1

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

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