Public Function BeginRefer ( _
		referTarget As RealTimeAddress, _
		referStatus As ReferStatus, _
		signalingHeaders As IEnumerable(Of SignalingHeader), _
		userCallback As AsyncCallback, _
		state As Object _
) As IAsyncResult

public IAsyncResult BeginRefer (
		RealTimeAddress referTarget,
		ReferStatus referStatus,
		IEnumerable<SignalingHeader> signalingHeaders,
		AsyncCallback userCallback,
		Object state
)

Parameters

referTarget

RealTimeAddress that contains the refer Uri.

referStatus

The refer status object provided by the caller to signal refer state change

signalingHeaders

Headers required for this refer.

userCallback

The method to be called when the Refer operation is complete.

state

The state to be passed back to the callback.

Return Value

The platform supports multiple Refer operations at the same time. Some clients may not support parallel Refer operations. Until the first notification is received, the capability of the remote client is not known. For this reason, the first Refer operation is special in the sense the subsequent Refer operations are queued until first notify is received to learn the capability of the remote client. If the remote supports parallel Refer operations, the queued Refer operations are all released. If the remote does not support parallel Refer operations, the Refer operations are carried out one at a time. When the terminating notify is received, the next Refer operation is started. For this reason, calling synchronous method to send Refer or waiting on the operation to complete (EndRefer) before the callback is called are highly discouraged.

Development Platforms

Target Platforms