Definition of event delegate you should use if you want to receive the OnCallStateChange event.
[Visual Basic]
Public Delegate Sub OnCallStateChange( _
ByVal Sender As Object, _
Byval e As OnCallStateChangeArgs_
)
[C#]
public delegate void OnCallStateChange(
object Sender,
OnCallStateChangeArgs e
);
Namespace: TAPIEx
Assembly: TAPIEx.Net.Dll