llAuthors.authors.Rows(i)
If (row("au_lname").ToString() =
state.Author) Then
found = True
End If
i = i + 1
End
While
If (found) Then
Dim cb As AsyncCallback =
state.originalCallback
' Calls the second XML Web service, because the
author is
' valid.
rs.BeginReturnedStronglyTypedDS(state.Author,
cb, state)
Else
' Cannot throw the exception in this function or
the XML Web
' service will hang. So, set the state argument to
the
' exception and let the End method of the chained XML Web
'
service check for it.
Dim ex As ArgumentException = New
ArgumentException( "Author does not exist.", "Author")
Dim cb As
AsyncCallback = state.originalCallback
' Call the second XML Web
service, setting the state to an
'
exception.
rs.BeginReturnedStronglyTypedDS(state.Author, cb,
ex)
End If
End Sub
' Define the End method.
＜WebMethod()＞
_
Public Function EndGetAuthorRoyalties(ByVal asyncResult As
_
IAsyncResult) As localhost.AuthorRoyalties
' Return the
asynchronous result from the other XML Web service.
Return
remoteService.EndReturnedStronglyTypedDS(asyncResult)
End
Function
End Class
' Class to wrap the callback and state
for the intermediate asynchronous
' operation.
Public Class
AsyncStateChain
Public originalCallback As AsyncCallback
Public
originalState As Object
Public Author As String
End Class
End
Namespace
上一页 [1] [2] |
