SoapHeader Class

When overridden in a derived class, represents the content of a SOAP header.

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

public abstract class SoapHeader
public abstract class SoapHeader
public abstract class SoapHeader
Not applicable.

SOAP headers offer a method for passing data to and from an XML Web service method if the data is not directly related to the XML Web service method's primary functionality. For instance, an XML Web service might contain several XML Web service methods that each require a custom authentication scheme. Instead of adding parameters to each XML Web service method for the custom authentication scheme, a SoapHeaderAttribute, referring to a class deriving from SoapHeader, can be applied to each XML Web service method. The implementation for the class deriving from SoapHeader handles the custom authentication scheme. In this manner, the XML Web service method implements only the functionality specific to it and adds additional functionality using a SOAP header.

The following list outlines the basic steps to receiving and processing a SOAP header:

  1. Create a class that derives from SoapHeader representing the data passed into the SOAP header.

  2. Add a member to the class implementing an XML Web service or an XML Web service client proxy class, of the type created in the first step.

  3. Apply a SoapHeaderAttribute to the XML Web service method or the corresponding method in the proxy class, specifying the member created in the second step in the MemberName property.

  4. Within the XML Web service method or XML Web service client code, access the MemberName property to process the data sent in the SOAP header.

The following MyWebService XML Web service defines the MyHeader SOAP header and requires it to be sent with any calls to the MyWebMethod XML Web service method. Additionally, MyWebMethod receives any SOAP headers other than the MyHeader SOAP header.

<%@ WebService Language="C#" Class="MyWebService"%>
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml;
using System;

// Define a SOAP header by deriving from the SoapHeader base class.

public class MyHeader : SoapHeader {
    public string MyValue;

public class MyWebService {

    public MyHeader myHeader;
    // Receive all SOAP headers besides the MyHeader SOAP header.
    public SoapUnknownHeader[] unknownHeaders;
    [SoapHeader("myHeader", Direction=SoapHeaderDirection.InOut)]

    //Receive any SOAP headers other than MyHeader.

    public string MyWebMethod() {

       foreach (SoapUnknownHeader header in unknownHeaders) {
           // Perform some processing on the header.
       if (header.Element.Name == "MyKnownHeader")
               header.DidUnderstand = true;
                // For those headers that cannot be  
                // processed, set the DidUnderstand property to false.
                header.DidUnderstand = false;
       return "Hello";


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 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, 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

.NET Compact Framework

Supported in: 2.0, 1.0

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