SipSubscription.BeginSubscribe Method
Creates an subscribe request body and puts the workItem in queue to invoke Subscribe.
Namespace: Microsoft.Rtc.Signaling
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
Syntax
'Declaration
Public Function BeginSubscribe ( _
userCallback As AsyncCallback, _
state As Object _
) As IAsyncResult
'Usage
Dim instance As SipSubscription
Dim userCallback As AsyncCallback
Dim state As Object
Dim returnValue As IAsyncResult
returnValue = instance.BeginSubscribe(userCallback, _
state)
public IAsyncResult BeginSubscribe(
AsyncCallback userCallback,
Object state
)
Parameters
- userCallback
Type: System.AsyncCallback
The method to be called when the asynchronous operation is completed.
- state
Type: System.Object
A user-provided object that distinguishes this particular asynchronous operation from other asynchronous operations.
Return Value
Type: System.IAsyncResult
An IAsyncResult that references the asynchronous operation.
Exceptions
| Exception | Condition |
|---|---|
| InvalidOperationException | Thrown when the Subscribe/BeginSubscribe operation to this SipSubscription had already been called. |
| InvalidOperationException | Thrown when the endpoint is terminating. |
| InvalidOperationException | Thrown if event package is "vnd-microsoft-roaming-self" and RealTimeEndpoint already have a subscription for this event. |
Remarks
Multiple subscription for the event "vnd-microsoft-roaming-self" are not allowed from same endpoint, so establishing another subscription session for this event will cause InvalidOperationException.