SipSubscription.BeginRefresh Method
Creates a transaction async result to refresh an existing subscription and puts the workitem in queue. Refresh is allowed only if the current subscription state is valid. Multiple simultaneous refreshes are allowed, but not recommended for the application.
Namespace: Microsoft.Rtc.Signaling
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
Syntax
'Declaration
Public Function BeginRefresh ( _
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.BeginRefresh(userCallback, _
state)
public IAsyncResult BeginRefresh(
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 current subscription signaling state is not Subscribed. |