Develop Reference

Order of WindowHandles

I'm encountering an issue where WebDriver seems to change the order of WindowHandles. This causes us to close the wrong one intermittently after getting them in some cases.
What seems to happen is the previously established first window handle is returned as a subsequent handle, which causes my logic to of course, close the wrong one.
Is WebDriver supposed to return the window handles in the same order every time (order of first opened window to last?). This is what I initially expected, but now I'm not so sure.
I should also mention the problem seems to only occur in IE right now, but I'm not certain if this is a more generic issue.
Here is how I'm closing the active window and switching back to the root window.
public void Close()
{
//switch to latest window
string windowName = string.Empty;
if (_driver.WindowHandles.Count > 1)
{
//get 'root' window in list
windowName = _driver.WindowHandles[0];
_driver.Close();
_driver.SwitchTo().Window(windowName);
}
else
{
_driver.Close();
}
}
We're on WebDriver 2.45 (C# bindings, 32-bit IEDriver). If there is a method to close the active window in the C# bindings that would most likely solve this issue as well.

This pop up window handler is entirely unordered as per my understanding. I remember having same conversation on SO and luckily JimEvans(one of the contributors of Selenium) chimed in and clarify few factors. I read about the PopupWindowFinder of Selenium .NET bindings and found that class can make your life lot easier. API is here. However, the whole order issue is entirely complex and painful to deal with. See this thread. Just don't want to reinvent the wheel.

ShareLinkTask Serialization.InvalidDataContractException WP8

I'm having an issue with the ShareLinkTask function from WP8.
I have an app with different pages (to view Comics - one to navigate through the Comics and one page to list a thumbnailpreview of all Comics).
The ShareLinkTask function works just fine as long as I stay in the MainPage.xaml. But when I switch to the Thumbnails.xaml (via NavigationService.Navigate...), select a new cartoon and share it the ShareLinkTask.Show() will show the sharing page and then crash the whole app.
If I make a try-catch around the ShareLinkTask.Show() no exception is thrown.
Here is the ShareLink function - it's called via the "Hold gesture":
ShareLinkTask shareLink = new ShareLinkTask();
shareLink.Title = "a";
shareLink.LinkUri = new Uri(b);
shareLink.Message = "Look at that handsome cartoon!";
try
{
shareLink.Show();
}
catch (Exception a)
{
MessageBox.Show(a.ToString());
}
From the console I get this error line: "System.Runtime.Serialization.InvalidDataContractException" occoured in System.Runtime.Serialization.ni.dll
Now Google doesn't now anything about this problem somehow - to be honest I don't really get / understand what's happening - I don't think that I serialize anything anywhere...
I suggest that I do something wrong by switching back to the MainPage.xaml. All indices etc. are correct and every other function of the app is just working fine.
Does anyone know where to look for the error?
Thanks in advance.

When you call Show, your application is put into a dormant state and may be terminated if the user navigates away instead of completing the task.
When your app is put into a dormant state your data gets serialized, but only classes with "DataContact" attributes can be serialized correctly. So the problem is - you are holding some UNSERIALIZABLE data in you app (Like in PhoneApplicationService.Current.State) . Find out what class causes exception.
Your exception should be like this:
System.Runtime.Serialization.InvalidDataContractException: Type 'TYPE HERE' cannot be serialized.
That will give you a hint of what's going on.

Use a proxy with webBrowser control C#/.net 3.5

I need some help from someone who has already use the webBrowser control along with a proxys.
What I need is the following.
1 - Set a proxy for a webBrowser control.
2 - Load a specific site.
3 - Execute a routine over the site.
4 - Set a diferent proxy for the webBrowser control.
5 - Load another site.
6 - Execute the same routine from point number 3.
And the process keeps in that way, looping from a list of proxys, until all of them had been used.
But. I'm having some problems with the app. to do that:
1 - I'm using the code attached to set the proxy into the webBrowser control, but seems to work only once during the execution, when I call it again in the loop it just doesn't work, I can get t ounderstand why.
2 - I'm having problems to determine when the page has loaded completely, I mean, when I set the first site to load, I need the program to wait until it has finish to load, and after that execute the routine over it, and continue with the process.
Hope some one could help me with this...
/// The function that I'm using -----------------------------
private void SetProxy(string Proxy)
{
MessageBox.Show("Setting :" + Proxy);
string key = "Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings";
RegistryKey RegKey = Registry.CurrentUser.OpenSubKey(key, true);
RegKey.SetValue("ProxyServer", Proxy);
RegKey.SetValue("ProxyEnable", 1);
}
// The app logic --------------------------------------
SetProxy("190.97.219.38:80");
webBrowser1.Navigate("http://www.whatismyip.com/");
ExecuteRoutine();
SetProxy("187.93.77.235:80");
webBrowser1.Navigate("http://www.whatismyip.com/");
ExecuteRoutine();
SetProxy("109.235.49.243:80");
webBrowser1.Navigate("http://www.whatismyip.com/");
ExecuteRoutine();

Perhaps this link is useful:
http://blogs.msdn.com/b/jpsanders/archive/2011/04/26/how-to-set-the-proxy-for-the-webbrowser-control-in-net.aspx
I tested the code and it seemed to work. But two points are important:
It's not compatible to projects in compile mode "Any CPU" (x86 works fine)
JUST for HTTP proxy servers ; not for SOCKS

1- I guess webBrowser control checks the proxy only while its is created, so create a new control after setting the proxy
2- Navigate is not a blocking call and does not wait till page it loaded, use webBrowser.DocumentCompleted event
Below code should work (Not tested)
void Exec(string proxy,string url)
{
var th = new Thread(() =>
{
SetProxy(proxy);
using (WebBrowser wb = new WebBrowser())
{
wb.DocumentCompleted += (sndr, e) =>
{
ExecuteRoutine();
Application.ExitThread();
};
wb.Navigate(url);
Application.Run();
}
});
th.SetApartmentState(ApartmentState.STA);
th.Start();
th.Join();
}

I had a somewhat similar question in the past. The accepted answer for the question suggests to take a look at this Microsoft Knowledge Base article:
"How to programmatically query and set proxy settings under Internet Explorer"
Basically, you have to do some P/Invoke and call some WinInet DLL functions. Although I never tried it in a real-world project, I strongly assume that this is the way to go.

Just to let you all know, this guy has posted 5 question, all asking the same thing, and based on his first question and how badly he was knocked down, it seems he is trying to commit some type of cybercrime. Now, based on my reading of his intellect, he'll probably end up in prison really quickly, but I'm just thinking perhaps we can save him from that by letting him know that it's not possible to provide an imaginary IP address to services you are communicating with (since if you did, the service will not be able to reach you to provide a response). Here is his entertaining list:
https://stackoverflow.com/questions/12045317/how-to-hide-my-ip-address-c-net-3-5
Use a proxy with webBrowser control C#/.net 3.5
how to pass ip-address to webBrowser control
how to use custom ip address to browse a web page c#/.net
https://stackoverflow.com/questions/12019890/how-to-load-webpage-using-user-provided-ipaddress-webbrowser-control-c-net
And now, I think he has created a new username, user1563019, with more proxy/settings questions below:
https://stackoverflow.com/users/1563019/user1563019

Problems getting newly created thread to send outputs to asp:panel in ASP.NET C#

I'm creating a file processor for use in an intranet.
I described it in another question - ERR_EMPTY_RESPONSE when processing a large number of files in ASP.Net using C#
Now, as suggested on above question's answer, I'm trying to use threads to execute the file processing task.
But there is a problem. I need the newly created thread to write feedbacks to a component in page (asp:panel, or div, or whatever). Those feedbacks would be results from several database operations.
The application reads those txts, interprets each line of it, and insert data in database. Each line inserted in database must return a feedback, like "registry 'regname' inserted successfully", or "i got problems inserting registry 'regname' in file 'filename', skipping to next registry".
I did test with something very simple:
protected void DoImport()
{
try
{
MainBody.Style.Add(HtmlTextWriterStyle.Cursor, "wait");
int x = 0;
while (x < 10000)
{
ReturnMessage(String.Format("Number {0}<hr />", x), ref pnlConfirms);
x++;
}
}
catch (Exception ex)
{
ReturnMessage(String.Format("<font style='color:red;'><b>FATAL ERROR DURING DATA IMPORT</b></font><br /><br /><font style='color:black;'><b>Message:</b></font><font style='color:orange;'> {0}</font><br />{1}", ex.Message, ex.StackTrace), ref pnlErrors);
}
finally
{
MainBody.Style.Add(HtmlTextWriterStyle.Cursor, "default");
}
}
This function is called from Page_Load, and fills an asp:panel called "pnlConfirms" with a row of numbers, but all at once, on load.
I changed it to:
protected void DoImport()
{
try
{
MainBody.Style.Add(HtmlTextWriterStyle.Cursor, "wait");
ThreadPool.QueueUserWorkItem(new WaitCallback(DoWork));
}
catch (Exception ex)
{
ReturnMessage(String.Format("<font style='color:red;'><b>FATAL ERROR DURING DATA IMPORT</b></font><br /><br /><font style='color:black;'><b>Message:</b></font><font style='color:orange;'> {0}</font><br />{1}", ex.Message, ex.StackTrace), ref pnlErrors);
}
finally
{
MainBody.Style.Add(HtmlTextWriterStyle.Cursor, "default");
}
}
private void DoWork(Object stateInfo)
{
int x = 0;
while (x < 10000)
{
ReturnMessage(String.Format("Number {0}<hr />", x), ref pnlConfirms);
x++;
}
}
And both uses this function:
public void ReturnMessage(string message, ref Panel panel, bool reset = false)
{
if (reset)
{
panel.Controls.Clear();
}
Label msg = new Label();
msg.Attributes.Add("width", "100%");
msg.Text = message;
panel.Controls.Add(msg);
}
I need ThreadPool.QueueUserWorkItem(new WaitCallback(DoWork)); to fill those asp:panels with feedbacks - like insertion errors and warnings.
My code already has those feedbacks under try...catch statements, but they're not getting output to any asp:panel from threadpool (it works when invoked directly from DoImport() function, like in the first example I posted).
I'm doing something very wrong, but I can't find out what (and I'm researching this for almost 2 weeks). Please, help!

In ASP.NET, when a browser requests a page, that page is rendered and sent to the browser as soon as its processing finishes, so the browser will show the page as it's finally rendered.
According to your code you're trying to render a page, show a wait cursor, and expect it's shown on the browser and then, the cursor is changed by a default cursor. As I explained, independently from using or not additional threads, the page won't be sent to the browser until it's completely rendered. So you'l never see the wait cursor on the client side.
The easiest wait to get what you're trying to do is to use web services (traditional .asmx or WCF) and AJAX (jquery os ASP.NET AJAX).
1) create a web service that does the processing
2) create a page which is sent to the browser, and, using javascript (jQuery or ASP.NET AJAX) make a call to the web service, and show something to let the user know that the request is being processed. (a wait cursor, or even better an animated gif)
3) when the process finishes, your javascript will get the responde from the web service, and you can update the page to let the user know the process has finished.
if you don't have experience on javascript, you can make most of this task using:
ScriptManager which can be used to create a javascript web service proxy for your client side (other interesting article) and is required for the rest of the controls
some javascript (or jquery) which can be use to update the "process running/ process finished hints" on the client side. I.e. when the call to the web service ends, you can use javascript to update the page using DOM, or load a new page or the same page with an special parameter to show the result of the process
In this way you can do what you want:
1) show a page in a state that shows the process is running
2) show the same, or other page, in a state that shows the end of the process
The trick is comunicating the browser with the server, and this can only be done using some of the available ajax techniques.
Another typical technique is using jQuery.ajax, like explained in encosia.com
According to the OP message, the process of all the files would be so slow that it would tiemout the web service call. If this is the case, you can use this solution:
1) Create a web service that process one (or a batch) of the pending files, and returns at least the number of pending files when it finishes the processing of the current file (or batch).
2) from the client side (javascript), call the web service. When it finishes, update the page showing the number of pending files, and, if this number is greater than zero, call the web service again.
3) when the call to the web service returns 0 pending files, you can update the page to show the work is finished, and don't call it any more.
If you process all the files at once, there will be no feedback on the client side, and there will also be a timeout. Besides, IIS can decide to stop the working thread which is making the work. IIS does this for several reasons.
A more reliable solution, but harder to implement, is:
1) implement a Windows Service, that does the file processing
2) implement a web service that returns the number of pending files (you can communicate the Windows Service and Web App indirectly using the file system, a database table or something like that)
3) use a timer (ajax timer, or javascript setInterval) from your web page to poll the server every N seconds using the web service, until the number of pending files is 0.
An even harder way to do this is hosting a WCF service in your Windows Service, instead of the indirect communication between your web app and windows service. This case is much more complicated because you need to use threads to do the work, and attend the calls to the wcf service. If you can use indirect communitacion it's much easier to implemente. The dtabse table is a simple and effective solution: your working process updates a row a table whenever it process a file, and the web service reads the progress state from this table.
There are many different soultions for a not so simple problem.

You are starting new thread (or more precise running your code on one of free threads in thread pool)and not waiting for results in main thread. Something like Thread.Join (if you would use manual thread creation) or other synchronization mechanism as events need to be used if you want to go this route.
The question you've linked to suggests using asynchronous pages which you are not doing. You would start processing request, kick off the task and release the thread, when the task is finished you complete request.
Side note: consider simply doing all conversion on main thread that handles request. Unless you expect slow I/O to complete the task moving CPU work from one thread to another may not produce significant gains. Please measure performance of your current solution and confirm that it does not meet performance goals you have set up for your application. (this does not apply if you doing it for fun/educational purposes).

How to reduce the CPU usage when a progress change event handler is fired?

I had created a BHO application with the help of this link.
If I Build the source code obtained in above article, the CPU usage is increased to 70-80%.
How can I reduce this?
In the above article, instead of Document complete event handler, i used progresschange event handler.
In the foreach loop, I used to check the tagname of every tag of a web page, while building the above code (or after registering the dll), the CPU usage was going on increasing from 10-80 percent which may cause problems if there is web page with lot of data(elements).....
I want to avoid this, Is there any method such that i can get all the tagnames of all the tag present in a web page.
Please suggest something such that i can avoid this problem.
Thanks...
The code which causes problem is in bold characters.
For each and every tag element found, It has display the message box containing the tagname of the tag element.
The code where I get problem is:
public void onProgressChange(int Progress, int ProgressMax)
{
document = (HTMLDocument)webBrowser.Document;
foreach(IHTMLElement tempElement in (IHTMLElementCollection)document.documentElement.all)
{
System.Windows.Forms.MessageBox.Show(" Tagname:"+ tempElement.tagname);
}
}
public int SetSite(object site)
{
if (site != null)
{
webBrowser = (WebBrowser)site;
webBrowser.ProgressChange += new DWebBrowserEvents2_ProgressChangeEventHandler(this.onProgressChange);
}
else
{
webBrowser.ProgressChange = new DWebBrowserEvents2_ProgressChangeEventHandler(this.onProgressChange);
webBrowser = null;
}
return 0;
}
This Event is generated repeatedly. How to reduce CPU usage?

This is a question without an answer. Your CPU usage problem is a result of what your doing, not so much how. IE is a dog, especially if you walking the all collection. Remember each and every object has to be marshaled into .Net for you to access it. I would recommend you approach your problem another way, or use a parser other than IE to process the HTML. You can use the WebClient class to load the HTML, then feed the result to whatever parser you like. Running a simple google search will turn up several alternative parsers:
http://www.google.com/search?hl=en&rlz=1C1GGLS_enUS330US330&q=html+parser+C%23+.net&aq=f&oq=&aqi=
If for whatever reason your stuck with IE, you need to find an alternative answer to the foreach statement on the document.all collection.

This Event is generated repeatedly. How to reduce CPU usage?
Function onProgressChange can be potentially invoked very very fast depending on webBrowser implementation.
Try rewriting onProgressChange to skip some of it's calls and to do actual work once in a while, for example once per second.