MessageFilter Class

.NET Framework (current version)

abstract base class for different classes of filters used to query messages.

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

Inheritance Hierarchy

Syntax

C++

[DataContractAttribute]
[KnownTypeAttribute((XPathMessageFilter^::typeid))]
[KnownTypeAttribute((ActionMessageFilter^::typeid))]
[KnownTypeAttribute((MatchAllMessageFilter^::typeid))]
[KnownTypeAttribute((MatchNoneMessageFilter^::typeid))]
public ref class MessageFilter abstract

Constructors

	Name	Description
	MessageFilter()	When called in a derived class, initializes a new instance of the MessageFilter class.

Methods

	Name	Description
	CreateFilterTable<FilterData>()	Creates a filter table for a filter that has a specified type of data associated with it.
	Equals(Object^)	Determines whether the specified object is equal to the current object.(Inherited from Object.)
	Finalize()	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)
	GetHashCode()	Serves as the default hash function. (Inherited from Object.)
	GetType()	Gets the Type of the current instance.(Inherited from Object.)
	Match(Message^)	When overridden in a derived class, tests whether a message satisfies the filter criteria. The body cannot be examined.
	Match(MessageBuffer^)	When overridden in a derived class, tests whether a buffered message satisfies the criteria of a filter.
	MemberwiseClone()	Creates a shallow copy of the current Object.(Inherited from Object.)
	ToString()	Returns a string that represents the current object.(Inherited from Object.)

MessageFilter is an abstract class that developers implement in order to specify the criteria to use for inspecting messages. Typically, filters are used by an endpoint application to determine what to do with a message based on an examination of some part of the message. A queuing process, for example, can use an XPath 1.0 query to check the priority element of a known header to determine whether to move a message to the front of the queue.

Filters are stored in a filter table that implements IMessageFilterTable<TFilterData>. Each filter in the table is associated with specified filter data that can be used to indicate what actions to take if a message matches the filter. The Match methods are used to determine if a message satisfies a filter.

The criteria used by a filter cannot be changed once the filter is constructed because the filter tables have no way to detect a change. The only way to modify the criteria of a filter is to construct a new one and delete the existing filter.

The following classes implement the abstractMessageFilter class:

XPathMessageFilter uses an XPath 1.0 expression to specify the criteria for a match.
MatchAllMessageFilter matches all messages.
MatchNoneMessageFilter matches none of the messages.
ActionMessageFilter tests whether the action of a message is one of a specified set of actions.
EndpointAddressMessageFilter tests whether a message satisfies a specified endpoint address.

ChannelListenerBase<TChannel> is an abstract base class that you can use for writing non-queuing listeners.

Version Information

.NET Framework
Available since 3.0

Thread Safety

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