ASP.NET DllImport导致应用程序退出

[DllImport(@\"MyAntiquatedLibrary.dll\")
[SecurityPermission(SecurityAction.Assert, Unrestricted = true)]
internal static extern void GetConnectionString(string port, string server, string instance, [Out] StringBuilder output);

void GetConnectionString(const char far *Portname, const char far *ServerName const char far *InstanceName, char far *retConnectionName);

protected void Page_Load(object sender, EventArgs e)
{
  try
  {
    var connectionString = new StringBuilder();
    GetConnectionString(null, \"myHost\", \"myInstance\", connectionString);
    MyLabel.Text = connectionString.ToString();
  }
  catch(Exception ex)
  {
    MyLabel.Text = string.Format(\"Something went wrong: {0}\", ex.Message);
  }
}

AccessViolationException was unhandled.
Attempted to read or write protected memory.  This is often an indication that other memory is corrupt.