Threading with manualResetEvent

Hello,

I have the following code in a class library. And I wait for a call back into my main application. I am making a DownloadStringAsync call so I have to wait a few seconds to get the callback after it has finished. I have a 3 of these calls to wait for (but for being simple just testing with one), so in my main application I am using ManualResetEvent to wait all of them to finish. So I will block until they have been set in the callback functions.

However, after testing the callback don't get called. I am thinking when the code gets blocked by the ManualResetEvent as its blocking the DownloadStringAsync. As when I comment out this code everything works fine.

So I think as soon as I make a call to: objNoGateway.NoGatewayStatus(sipUsername, statusDisplay1.PhoneNumber); And when the code reaches here: handle.WaitOne(); It will block the code in the class library.

I think the main UI thread is being blocked, so cannot receive any messages.

Many thanks for any suggestions,

My class library:

Code:

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' Event handler that makes a call back in my main application
        ' Event handler and method that handles the event
        Public NoGatewayCompletedEvent As EventHandler(Of NoGatewayEventArgs)
        ' The method that raises the event.
        Private Sub OnNoGatewayCompleted(ByVal sender As Object, ByVal e As NoGatewayEventArgs)
                If NoGatewayCompletedEvent IsNot Nothing Then
                        NoGatewayCompletedEvent(Me, e)
                End If
        End Sub

        ' Start the Async call to find if NoGateway is true or false
        Public Sub NoGatewayStatus(ByVal sipUsername As String, ByVal phoneNumber As String)
                Dim strURL As String = String.Format("http://xxxxxxxxxxxxxxx={0}&CalledNumber={1}", sipUsername, phoneNumber)

                If (Not wc.IsBusy) Then
                        Try
                                Dim errorMsg As String = String.Empty
                                wc.DownloadStringAsync(New Uri(strURL))
                        Catch ex As WebException
                                Console.WriteLine("IsNoGateway: " & ex.Message)
                        Catch ex As Exception
                                Console.WriteLine("IsNoGateway: " & ex.Message)
                        End Try
                Else
                        Console.WriteLine("WebClient: IsNoGateWay(): Busy please try again")
                End If

        End Sub

        Private Sub wc_DownloadStringCompleted(ByVal sender As Object, ByVal e As DownloadStringCompletedEventArgs)
                If e.Error Is Nothing Then
                        If e.Result = "No gateway" Then
                                OnNoGatewayCompleted(Me, New NoGatewayEventArgs(validateResponse_e.VALIDATION_FAILED))
                                Console.WriteLine("NoGatway() DownloadedCompleted: " & e.Result)
                        Else
                                OnNoGatewayCompleted(Me, New NoGatewayEventArgs(validateResponse_e.OK))
                                Console.WriteLine("NoGateway() DownloadCompleted: " & e.Result)
                        End If
                Else
                        Me.OnNoGatewayCompleted(Me, New NoGatewayEventArgs(validateResponse_e.SERVER_FAILED))
                        Console.WriteLine("No Gateway: DownloadCompleted() Error: " & e.Error.Message)
                End If
        End Sub

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In my main application I register this callback. And wait for the for the result. Then set the ManualResetEvent.

Code:

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Private waitValidateCallResponse() As ManualResetEvent = { New ManualResetEvent(False), New ManualResetEvent(False), New ManualResetEvent(False) }
        ' Event handler for NoGateway event
        Private Sub OnNoGatewayCompleted(ByVal sender As Object, ByVal e As NoGatewayEventArgs)
                Console.WriteLine("OnNoGatewayComleted: " & e.noGateway)
                waitValidateCallResponse(0).Set()
        End Sub

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Where I am start and then wait for the thread to finish

Code:

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Private Sub ValidateDialedNumber()
          'Incorrect country code has been entered.
          Using objNoGateway As New NoGateway()
                        AddHandler objNoGateway.NoGatewayCompletedEvent, AddressOf OnNoGatewayCompleted
                        objNoGateway.NoGatewayStatus(sipUsername, statusDisplay1.PhoneNumber)
          End Using

          ' Block here - Wait for all reponses to finish before moving on
          'WaitHandle.WaitAll(waitValidateCallResponse); 
          waitEvent.WaitOne(5000, True)
          Console.WriteLine("All thread finished")
End Sub

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