Supports network communication that allows reading and writing whole messages using a WebSocket.
Public NotInheritable Class MessageWebSocket Implements IWebSocket, _ IDisposable
The MessageWebSocket class has these types of members:
The MessageWebSocket class has these constructors.
|MessageWebSocket||Creates a new MessageWebSocket object.|
The MessageWebSocket class has these events.
|Closed||Occurs when a close frame is received on the MessageWebSocket object as part of the close handshake.|
|MessageReceived||An event that indicates that a message was received on the MessageWebSocket object.|
The MessageWebSocket class has these methods. With C#, Visual Basic, and C++, it also inherits methods from the Object class.
|Close(UInt16, String)||Closes the MessageWebSocket object and indicates a reason for the closure.|
|ConnectAsync||Starts an asynchronous operation to connect to a remote network destination on a MessageWebSocket object.|
|Dispose [C#, VB]||Performs tasks associated with freeing, releasing, or resetting unmanaged resources.|
|SetRequestHeader||Adds an HTTP request header to the HTTP request message used in the WebSocket protocol handshake by the MessageWebSocket object.|
The MessageWebSocket class has these properties.
|Read-only||Gets socket control data on a MessageWebSocket object.|
|Read-only||Gets socket information on a MessageWebSocket object.|
|Read-only||Gets the output stream to write to the remote network destination on a MessageWebSocket object.|
The MessageWebSocket class provides a message-based abstraction of the WebSocket protocol. When using MessageWebSocket, the entire WebSocket message is read or written in a single operation. In contrast, the StreamWebSocket allows sections of a message to be read with each read operation, rather than requiring the entire message to be read in a single operation.
For UTF-8 messages, MessageWebSocket must be used. StreamWebSocket only supports binary messages.
You must write code to handle exceptions when you call asynchronous methods on the MessageWebSocket class. Exceptions can result from parameter validation errors, name resolutions failures, and network errors. Exceptions from network errors (loss of connectivity, connection failures, and HTTP server failures, for example) can happen at any time. These errors result in exceptions being thrown. If not handled by your app, an exception can cause your entire app to be terminated by the runtime.
The Windows.Networking.Sockets namespace has a convenient helper method and enumeration for handling errors when using WebSockets. This can be useful for handling specific network exceptions differently in your app. An app can also use the HRESULT from the exception on parameter validation errors to learn more detailed information on the error that caused the exception.
For more information on possible exceptions and how to handle exceptions, see Handling exceptions in network apps.
On Windows Server 2012 and Windows Server 2012 R2, the Windows.Networking.dll that implements most of the classes in the Windows.Networking.Sockets namespace will fail to load unless the Media Foundation feature is enabled. As a result, apps that use MessageWebSocket and related WebSocket classes in the Windows.Networking.Sockets namespace will fail if the Media Foundation feature is disabled. Windows Server 2012 or Windows Server 2012 R2 installs with the Media Foundation feature disabled.
The Media Foundation feature can be enabled on Windows Server 2012 or Windows Server 2012 R2 using Server Manager or by entering the following text in a command prompt or a script:
dism /online /enable-feature /featurename:ServerMediaFoundation
After the Media Foundation feature is enabled, the user is prompted to restart. Once the computer is restarted, classes for sockets and WebSockets in the Windows.Networking.Sockets namespace will work as expected.
Minimum supported client
|Windows 8 [Windows Store apps, desktop apps]|
Minimum supported server
|Windows Server 2012 [Windows Store apps, desktop apps]|
- Connecting with WebSockets
- Handling exceptions in network apps
- Quickstart: Connecting with a MessageWebSocket
- Connecting with WebSockets sample
Build date: 11/16/2013