BeginTransfer Method (Call, CallTransferOptions, AsyncCallback, Object)
Intiates a transfer request to the remote participant of the current call to replace another existing call in Attended mode.
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
'Declaration Public Function BeginTransfer ( _ callToReplace As Call, _ callTransferOptions As CallTransferOptions, _ userCallback As AsyncCallback, _ state As Object _ ) As IAsyncResult
'Usage Dim instance As AudioVideoCall Dim callToReplace As Call Dim callTransferOptions As CallTransferOptions Dim userCallback As AsyncCallback Dim state As Object Dim returnValue As IAsyncResult returnValue = instance.BeginTransfer(callToReplace, _ callTransferOptions, userCallback, _ state)
public IAsyncResult BeginTransfer( Call callToReplace, CallTransferOptions callTransferOptions, AsyncCallback userCallback, Object state )
This is Supervised transfer since the operation involves another call and it waits for success or failure notifications from the remote regarding how the transfer is being carried out at the remote side. When the transfers is successfully by the existing remote participant, the current call is terminated. If it fails, the call is not affected. If callToReplace is passed as the instance of the call initiating the transfer, then this would be considered as the self-transfer.
[T:System.ArgumentNullException]: Thrown if the value is null.
[T:System.ArgumentException]: Thrown if the parameter is specified with unsupported headers, is used to override transferor value by any endpoint other than an Application Endpoint or is of type Unattended transfer.
[T:System.InvalidOperationException]: Thrown if the is not in Established state Current call is not in a valid state to initiate a transfer operation.