Begins an asynchronous operation to subscribe on the subscription.

Namespace:  Microsoft.Rtc.Collaboration.Presence
Assembly:  Microsoft.Rtc.Collaboration(in Microsoft.Rtc.Collaboration.dll)

Syntax

Visual Basic (Declaration) 
Public 
Overridable 
Function 
BeginSubscribe ( _
	
userCallback 
As 
AsyncCallback, _
	
state 
As 
Object _
) 
As 
IAsyncResult
C# 
public 
virtual 
IAsyncResult 
BeginSubscribe(
	
AsyncCallback 
userCallback,
	
Object 
state
)
Visual C++ 
public:
virtual 
IAsyncResult^ 
BeginSubscribe(
	
AsyncCallback^ 
userCallback, 
	
Object^ 
state
)
JavaScript 
function 
beginSubscribe(
userCallback, 
state);

Parameters

userCallback
Type: AsyncCallback
The method to be called when the asynchronous operation is completed.
state
Type: Object
A user-provided object that distinguishes this particular asynchronous operation from other asynchronous operations.

Return Value

An IAsyncResult that references the asynchronous operation.

Remarks

UCMA allows subscription to be reused. Hence, the application can re-subscribe to the same subscription after it has been unsubscribed.

Exceptions

Exception Condition
InvalidOperationException Thrown when the subscription is not in a valid state.

See Also