When using a SoapExtension, you must also derive a custom SoapExtensionAttribute. This attribute is used to "connect" methods in your web service or proxy class to the corresponding extension.
When creating a custom SoapExtensionAttribute, you need to override the ExtensionType property so that it returns the type of your custom SoapExtension class. You can then use your custom attribute to mark methods in your web service or proxy class. ASP.NET will automatically use the specified SoapExtension when the associated method is invoked.
public abstract class SoapExtensionAttribute : Attribute { // Protected Constructors protected SoapExtensionAttribute( ); // Public Instance Properties public abstract Type ExtensionType{get; } public abstract int Priority{set; get; } }