IRequestChannel.BeginRequest Method (Message, TimeSpan, AsyncCallback, Object)

Begins an asynchronous operation to transmit a request message to the reply-side of a request-reply message exchange within a specified interval of time.

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


Function BeginRequest ( _
    message As Message, _
    timeout As TimeSpan, _
    callback As AsyncCallback, _
    state As Object _
) As IAsyncResult
IAsyncResult BeginRequest(
    Message message,
    TimeSpan timeout,
    AsyncCallback callback,
    Object state


  • timeout
    Type: System.TimeSpan
    The TimeSpan that specifies the interval of time within which a response must be received. (On the defaults, see the remarks.)
  • callback
    Type: System.AsyncCallback
    The AsyncCallback delegate that receives the notification of the completion of the asynchronous operation transmitting a request message.
  • state
    Type: System.Object
    An object, specified by the application, that contains state information associated with the asynchronous operation transmitting a request message.

Return Value

Type: System.IAsyncResult
The IAsyncResult that references the asynchronous message transmission.


If the request message is larger that the maximum message size allowed by the binding being used, a QuotaExceededException should be thrown. The maximum message size is set by the MaxReceivedMessageSize property. The default value is 65536 bytes.

If a timeout is passed while calling the function then that value is used. If the SendTimeout is set on the binding, then the value on the binding is used if no timeout is specified while calling the function.

The DefaultSendTimeout is used if no timeout is specified on either the binding or while calling the function. This default value is 1 minute.

Notes to Implementers

The operation should throw a TimeoutException if the specified timeout is exceeded before the operation is completed.


The following code illustrates how to implement this method:

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.