Windows apps
Collapse the table of content
Expand the table of content
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

HttpMessageHandler Class

.NET Framework (current version)

The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

A base type for HTTP message handlers.

Namespace:   System.Net.Http
Assembly:  System.Net.Http (in System.Net.Http.dll)


public abstract class HttpMessageHandler : IDisposable


Initializes a new instance of the HttpMessageHandler class.


Releases the unmanaged resources and disposes of the managed resources used by the HttpMessageHandler.


Releases the unmanaged resources used by the HttpMessageHandler and optionally disposes of the managed resources.


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


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


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


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


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

System_CAPS_protmethodSendAsync(HttpRequestMessage, CancellationToken)

Send an HTTP request as an asynchronous operation.


Returns a string that represents the current object.(Inherited from Object.)

There are various HTTP message handles that can be used. These include the following.

  1. DelegatingHandler - A class used to plug a handler into a handler chain.

  2. HttpMessageHandler - A simple to class to derive from that supports the most common requirements for most applications.

  3. HttpClientHandler - A class that operates at the bottom of the handler chain that actually handles the HTTP transport operations.

  4. WebRequestHandler - A specialty class that operates at the bottom of the handler chain class that handles HTTP transport operations with options that are specific to the System.Net.HttpWebRequest object.

If developers derive classes from HttpMessageHandler and override the SendAsync method, they must make sure that SendAsync can get called concurrently by different threads.

This is necessary since methods on HttpClient can be called concurrently and need a guarantee of thread safety. So if a handler is assigned to an HttpClient instance, the SendAsync method of the handler may get called concurrently by the HttpClient instance and needs to be thread safe.

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.5
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1

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

Return to top
© 2017 Microsoft