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.
Namespace: Microsoft.Rtc.Collaboration.AudioVideo
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
Syntax
'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
)
Parameters
- callToReplace
Type: Microsoft.Rtc.Collaboration..::..Call
- callTransferOptions
Type: Microsoft.Rtc.Collaboration..::..CallTransferOptions
- userCallback
Type: System..::..AsyncCallback
- state
Type: System..::..Object
Return Value
Type: System..::..IAsyncResult
Remarks
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.
Exceptions
[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.