How do I even start debugging this.

[Doug Robertson]

First off, I'm a hardware/OS guy. I just write code on the side and I'm
completely self taught - so bear in mind my total lack of expertise.

I have a program originally written in VB2003 using the dotnet 1.1
framework. The program makes extensive use of Win32 API calls to help manage
and track remote access sessions with out clients. I've left it running for
days at a time on my system with no problems. It has always been stable.

I recently upgraded the program to VB2005 using the upgrade wizard. It
seemed to port cleanly with only minor cleanup needed (such as 2005 needing
more explicit references. i.e. "if result = dialogresult.ye s" becoming "if
result = windows.forms.d ialogresult.yes "). The problem is that under dotnet
2.0 the program is unstable. If I leave it minimized for several hours then
try to acess it from the taskbar, the program form will just display as a
blank white form. No actual error occurs, the form is just white. Task
manager shows the process running normally. It goes to not-responding when
you try to close it and has to be force closed. I have try...catch clauses
around everything and as far as I can tell, no exceptions are occuring. The
problem only occurs if the program has been idle for a long time. It's as if
Windows has simply decided to quit drawing the form.

Obviously no one can tell me exactly what's happening, my problem is that I
don't have even the vaguest idea how to start debugging something like this.
How do you troubleshoot a program that just hangs without causing an error?

Can somebody recommend an article or website (or even a book) that gives a
general debugging process for something like this?

[mg]

Doug Robertson wrote:

I have a program originally written in VB2003 using the dotnet 1.1
framework. The program makes extensive use of Win32 API calls to help manage
and track remote access sessions with out clients. I've left it running for
days at a time on my system with no problems. It has always been stable.

Doug,
I have written an almost identical application in VB2005. Here is the
code I use to start a RAS VPN connection and launch either the RDP
client or VNC:

Dim spVPN As New Process()
With spVPN
.StartInfo.File Name = oSettings.RASDi alPath
.StartInfo.UseS hellExecute = False
.StartInfo.Redi rectStandardOut put = True
.StartInfo.Wind owStyle = ProcessWindowSt yle.Hidden
.StartInfo.Crea teNoWindow = True
.StartInfo.Argu ments = VPNargs
.Start()
sOut = spVPN.StandardO utput.ReadToEnd
.WaitForExit(10 00)
Application.DoE vents()
ec = .ExitCode
End With
If Not spVPN Is Nothing Then spVPN.Close()

Debug.Print("ex it code: [" & CStr(ec) & "]" & vbCrLf & sOut)
If ec = 0 Then
Dim sp As New Process()
With sp
.StartInfo.File Name = launchApp
.StartInfo.UseS hellExecute = False
.StartInfo.Work ingDirectory = My.Application. Info.DirectoryP ath
.StartInfo.Argu ments = launchCMD
.Start()
.WaitForExit(10 00)
Application.DoE vents()
End With
If Not sp Is Nothing Then sp.Close()
Else
Select Case ec
Case 623
MsgBox("Support RAS phonebook entry not found.", MsgBoxStyle.OkO nly,
"Connection Error")
Case Else
MsgBox(sOut, MsgBoxStyle.OkO nly, "Connection Error")
End Select
End If

It uses a dummy RAS connectoid (the the right security/VPN settings)
that you can call with rasdial and command line switches.

One thing I have noticed is that RAS dial/hangup is very sensitive to
trying to 'rush' it when hanging up. Any help?