PowerTCP Mail for .NET
Exception Property
See Also  Send comments on this topic.
Dart.PowerTCP.Mail Namespace > SegmentEventArgs Class : Exception Property




Gets any exception which occurred during the asynchronous operation.

Syntax

Visual Basic (Declaration) 
Public ReadOnly Property Exception As Exception
Visual Basic (Usage)Copy Code
Dim instance As SegmentEventArgs
Dim value As Exception
 
value = instance.Exception
C# 
public Exception Exception {get;}
Managed Extensions for C++ 
public: __property Exception* get_Exception();
C++/CLI 
public:
property Exception^ Exception {
   Exception^ get();
}

Property Value

If any exception occurred during the asynchronous operation, this property will contain an Exception object describing the exception.

Example

The following example demonstrates asynchronous receiving and sending of data.
Visual BasicCopy Code
Private Sub AsynchTcpDemo()

   ' Attempt to connect to an echo port.
   Try
      Tcp1.Connect("myserver", 7)
   Catch ex As Exception
      Return
   End Try

   ' Send data, since we are connected to an echo port, the same data should be returned.
   ' The following code demonstrates asynchronously sending data. When data has been sent
   ' the EndSend event will be raised.

   Dim buffer() As Byte = System.Text.Encoding.Default.GetBytes("a")
   Tcp1.BeginSend(buffer, 0, buffer.Length, Net.Sockets.SocketFlags.None, Nothing)
End Sub

Private Sub Tcp1_EndSend(ByVal sender As Object, ByVal e As Dart.PowerTCP.SegmentEventArgs) Handles Tcp1.EndSend
   ' Check for exception
   If e.Exception Is Nothing Then

      ' Send is complete. Display info about the data sent.
      Debug.WriteLine("Byte count sent: " + e.Segment.Count)
      Debug.WriteLine("Data sent: " + e.Segment.ToString())
      
      Dim buffer(Tcp1.ReceiveBufferSize) As Byte

      ' Receive the data. The EndReceive event will be raised upon completion.
      Tcp1.BeginReceive(buffer, 0, buffer.Length, Net.Sockets.SocketFlags.None, Nothing)
    
    End If
End Sub

Private Sub Tcp1_EndReceive(ByVal sender As Object, ByVal e As Dart.PowerTCP.SegmentEventArgs) Handles Tcp1.EndReceive
   ' Check for exception
   If e.Exception Is Nothing Then

      ' Receive is complete. Display info about the data sent.
      Debug.WriteLine("Byte count received: " + e.Segment.Count)
      Debug.WriteLine("Data received: " + e.Segment.ToString())

      ' Close the connection
      Tcp1.Close()
    End If
End Sub
C#Copy Code
private void AsynchTcpDemo()
{
    // Attempt to connect to an echo port.
    try
    {
        tcp1.Connect("myserver", 7);
    }
    catch(Exception ex)
    {return;}

    // Send data, since we are connected to an echo port, the same data should be returned.
    // The following code demonstrates asynchronously sending data. When data has been sent
    // the EndSend event will be raised.

    byte[] buffer = System.Text.Encoding.Default.GetBytes("a");
    tcp1.BeginSend(buffer, 0, buffer.Length, System.Net.Sockets.SocketFlags.None, null);
}

private void tcp1_EndSend(object sender, Dart.PowerTCP.SegmentEventArgs e)
{
    // Check for exception
    if(e.Exception == null)
    {
        // Send is complete. Display info about the data sent.
        Debug.WriteLine("Byte count sent: " + e.Segment.Count);
        Debug.WriteLine("Data sent: " + e.Segment.ToString());
                

        byte[] buffer = new byte[tcp1.ReceiveBufferSize];
                    
        // Receive the data. The EndReceive event will be raised upon completion.
        tcp1.BeginReceive(buffer, 0, buffer.Length, System.Net.Sockets.SocketFlags.None, null);
    }
}

private void tcp1_EndReceive(object sender, Dart.PowerTCP.SegmentEventArgs e)
{
    // Check for exception
    if(e.Exception == null)
    {
        // Receive is complete. Display info about the data sent.
        Debug.WriteLine("Byte count received: " + e.Segment.Count);
        Debug.WriteLine("Data received: " + e.Segment.ToString());

        // Close the connection
        tcp1.Close();
    }
}

Remarks

Check this property to tell if an exception occurred during the asynchronous operation. If this property is null, no exception occurred.

The exception property is useful for checking exceptions and handling them appropriately. For example, if a bad command was sent to the server, a ProtocolException may be thrown. You could check this property to see if it was of type ProtocolException, than handle appropriately.

Requirements

Target Platforms: Microsoft .NET Framework 2.0

See Also

Documentation Version 3.2
© 2010 Dart Communications. All Rights Reserved.