InstantMessagingCall.BeginEstablish Method (ToastMessage, CallEstablishOptions, AsyncCallback, Object)
Begins the operation of establishing the instant messaging call on existing Conversation.
Namespace: Microsoft.Rtc.Collaboration
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
Syntax
'Declaration
Public Function BeginEstablish ( _
toastMessage As ToastMessage, _
options As CallEstablishOptions, _
userCallback As AsyncCallback, _
state As Object _
) As IAsyncResult
'Usage
Dim instance As InstantMessagingCall
Dim toastMessage As ToastMessage
Dim options As CallEstablishOptions
Dim userCallback As AsyncCallback
Dim state As Object
Dim returnValue As IAsyncResult
returnValue = instance.BeginEstablish(toastMessage, _
options, userCallback, state)
public IAsyncResult BeginEstablish(
ToastMessage toastMessage,
CallEstablishOptions options,
AsyncCallback userCallback,
Object state
)
Parameters
- toastMessage
Type: Microsoft.Rtc.Collaboration.ToastMessage
A short message which can be displayed to the recipient upon receipt. Can be null.
- options
Type: Microsoft.Rtc.Collaboration.CallEstablishOptions
Optional parameters to establish the call.
- 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 |
|---|---|
| ArgumentException | Thrown when the options parameter contains invalid or restricted signaling headers, or when the call is used as a third party call controller with custom MIME parts or with early media support. |
| InvalidOperationException | Thrown when the call is not in a valid state to perform this operation or does not have valid media provider to bind to. |
Remarks
toastMessage specifies the message that is displayed on the client when the callee is notified of an incoming call.