vshost32.exe crash when calling unmanaged DLL

Question

Hi all,

I'm using a VS 2005 app to interface against an unmanaged (Fortran) DLL. When I run the compiled executable straight from the command line, everything is fine - the DLL can be accessed, and I can work with the functions in the DLL.

Unfortunately, when I launch the app from VS 2005, I get a popup stating "vshost32.exe has stopped working" and no useful debugging information.

Has anyone experienced this behavior, or know why this might be occuring? I can't figure out why it would run fine when launched stand-alone, but not via vshost32.

(One last note: I am using .local files to force registered dlls to be used from cwd, but this particular dll is not registered. I'm just noting it here in case it helps.)

---

Thanks very much,

Mike

Answer 1

Not sure but you can disable use of the visual studio hosting process from Properties -> Debug

Answer 2

Might be that there is an unhandled exception. You could try to add the following code to handle all uncatched exceptions:

static void Main()
{
  // Add a handler for the UnhandledExceptionEvent
  AppDomain.CurrentDomain.UnhandledException +=
    new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);

  Application.EnableVisualStyles();
  Application.SetCompatibleTextRenderingDefault(false);
  Application.Run(new Form1());
}

static void CurrentDomain_UnhandledException
     (object sender, UnhandledExceptionEventArgs e)
{
    try
    {
        Exception ex = (Exception)e.ExceptionObject;

        MessageBox.Show(ex.ToString(), "Error", 
              MessageBoxButtons.OK, MessageBoxIcon.Stop);
    }
    finally
    {
        Application.Exit();  
    }
}

The reason for the underlying problem is that you might have a different working folder when debugging so that your native library is not found.

Answer 3

download dependency walker http://www.dependencywalker.com/ use it to open up your dll, and see if it relies on other dlls that are not present in that folder.

Answer 4

I had problem with crashes of vshost32.exe the problem vanished when I checked the checkbox:

Properties -> Debug -> Enable unmanaged code debugging

Does it work for you?