Getting around System.UnauthorizedAccessException : Access is denied

I am using Waitin RC2, WatiN-2.0.20.1089, Windows XP OS with IE8 With VS2008 and NUnit-2.5.7.10213. I have added the sites to the trusted list, I have thread sleeps, I have tried "WaitForComplete". yet when the script goes "back" I am still getting an unauthorized access exception. Here is a chunk of my code, the exceptions are never caught inspite of the fact that most of the code is in try catch blocks.

public string FindAllLinks()

    {
        /*
         * This function is designed to find and use all of the links on a given page.
         * After clicking on a link it waits for 400 milliseconds on the page so the page
         * has some time to load and then the function "hits the back button" reseting 
         * to the originating page.
         * This function is not meant to be recursive.
         */

        string message = "";
        bool flag = true;

        //Get a list of all links from the browser instance
        foreach (Link link in browserInstance.Links)
        {
            System.Threading.Thread.Sleep(1000);
            Console.WriteLine(link);
            try
            {//clicking on the link to make sure it leads somewhere
                link.Click();  //If the click fails hopefull we will thrwo out of the try block and not execute the next two commands.
                //Console.WriteLine(link);
            }
            catch (Exception)
            {//OOPs we have an error let's log a message.
                message = message + "The link titled " + link + " was not found, or did not work.\n";
                flag = false;
            }

     开发者_如何学运维       if (flag)
            {
                System.Threading.Thread.Sleep(1000);
                //browserInstance.WaitForComplete;
                try { browserInstance.Back(); }
                catch (UnauthorizedAccessException)
                {
                    //do nothing
                }
            }//close if flag

        }//close for each

        //return the message
        return (message);

    }//Close function


    [STAThread]
    [Test]
    public void TestTitleHomePage()
    {
        bool testPassed = false;

        if (browserInstance.Title.Contains("<title>"))

        {

            string message = FindAllLinks();

            if (message == "") { testPassed = true; }

        }//close if

        else { message = "The Title was not the same."; }


        Assert.IsTrue(testPassed, message);


    }// end TestTitleHomePage

I tried your code and I also get the exception. I think I understand what happens. When you first do Browser.Links, you get all the links of the current page, then you navigate to another page and return to the first page, but for WatiN it is a new page. So your enumeration cannot work because you enumerate though the links of the first page.

What I suggest you could do is to get all the Uri of the links, then try them one by one in a new browser

IEnumerable<Uri> uris = Browser.Links.Select(l => l.Uri);
foreach(Uri uri in Uris)
{
   try 
   {
      using(var browser = new IE(uri))
      {
          // do nothing or detect 404, 403, etc errors
      }

      // no error
   }
   catch(exception)
   {
      // log error
   }
}