Develop Reference

C# Download a complete weired HTML page

I'm sorry if this question has allready been answered , but I litterally spent more than two weeks searching the Internet for a solution to my issue.
Now , I definitly do not perform the best google searches , and it might seem that my question has several effective answers on the Internet. but I really tried every single solution that I found , without any positive results.
What i'm trying to do is simple , and I did it successfully on many websites :
Navigating to a website using WebBrowser (1).
Waiting for everything to load properly (document completed event).
Download the page using DocumentText property (1).
(1) : I also use WebClient from time to time.
And there it is , I get the html page , and I can exploit it anyway I like. The issue is with a particular website that I cannot obtain the full content inspite of using all the different solutions that I found. I suspected the fact that this page might need to load several scripts before getting the full content. Yet again, I read that WebBrowser does run all the necessarry scripts before triggering the " completed " event, so , apparently , that's not the issue. The page that i'm inquiring about is : http://www.coolmod#com/tarjetas-graficas-nvidia-pci-express
I tried , after that the WebBrowser loads the entire page , looking for random elements using GetElementByID property and checking if I get a null result. It appears that when I try getting an element that does not belong to the products list , i'm successful. But , whenever I try to get an element that belongs to the list it self , I always get a null. Which means , the list it self does not load. and I really don't know why. By the way , I do not prevent the WebBrowser. Navigate () from delivering multiple responses , I allow it to give as many feedbacks as possible , and still , the product list does not load , even when I pass the cookies. I Even tried copying all the content of the document and pasting it through the clipboard. Here is a simple example of what I try to do :
private void catalogueDownload()
{
System.Windows.Forms.WebBrowser wb = new System.Windows.Forms.WebBrowser();
wb.ScriptErrorsSuppressed = true;
wb.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(Catalogue_DocumentCompleted);
wb.Navigate("http://www.coolmod.com/tarjetas-graficas-nvidia-pci-express");
}
public void Catalogue_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
var wb = sender as System.Windows.Forms.WebBrowser;
string output = wb.DocumentText;
File.WriteAllText("testing.html", output);
}
Thanks for giving up your time to read all this.

System.Windows.Forms.WebBrowser is a bit outdated, If I were you, I would consider using an external library for that, Selenium would be my 1st choice, given it has all the necessary integrations with .NET Framework (and a lot of other languages)

End page background working, WP8, C#

I dont know if it is even possible, but is there some way how to "end" page in Windows Phone 8 app?
My problem is that i am using one delegate (to know when is my xml downloaded) on multiple pages. It works fine, but when i open one page, she initialize herself, i go on other page (trough back button) and new page initialize herself too. Everything is fine, but the previous page is still listening to the delegate and it is really big problem. So i need to get the previous page (that closed) into a same state like she was not ever opened.
I will be thankful for any advice (maybe i am thinking in wrong way now, i dont know, maybe the page just have to be de-initialize).
PS: If its necessary i will post the code, but i think it is not. :)
Okey here is some code:
In class whis is downloading XML i have delegate like this:
public delegate void delDownloadCompleted();
public static event delDownloadCompleted eventDownloadCompleted;
This class is downloading few different xml files depends of constructor in run(int number) method.
After is download complete and all information from xml are saved in my local list i call delegateCompled. if (eventDownloadCompleted != null)
{
eventDownloadCompleted();
}
Then i have few different pages. All pages are used for display specific data from downloaded xml. So on this specific page I have method that is fired when "downloadClass" says it is complet.
XML_DynamicDataChat.delDownloadCompleted delegMetoda = new XML_DynamicDataChat.delDownloadCompleted(inicialiyaceListu);
XML_DynamicDataChat.eventDownloadCompleted += delegMetoda;
This is that "inicializaceListu" method:
private void inicialiyaceListu()
{
Dispatcher.BeginInvoke(() =>
{
model = new datka();
// object model is just model where i am saving all specific list of informations that i got from xml files.
chatList9 = model.getChat(1);
gui_listNovinky.ItemsSource = chatList9;
gui_loadingGrid.Visibility = Visibility.Collapsed;
});
}
All of these works fine, but when i go back (with back button) and open other specific page with other specific information from other downloaded xml, previous page is still listening for the delegate and inicialiyaceListu() method is still fired everytime i complete download of xml.
So i need to say previous page something like: "hey page, you are now closed! Can you shut the **** up and stop work?!?"
I think that specific delegate for each pages could solve this, but it is not correct programing way.

I solved it nice and easy. It is really simple solution. I just created bool variable and set it false when i go back. In inicializaceListu() i have condition if it is true. If it is true do that stuffs when false do nothing.

c# customizing controls on a save dialog -- how to disable parent folder button?

I am working from the sample project here: http://www.codeproject.com/Articles/8086/Extending-the-save-file-dialog-class-in-NET
I have hidden the address/location bar at the top and made other modifications but I can't for the life of me manage to disable the button that lets you go up to the parent folder. Ist is in the ToolbarWindow32 class which is the problem. This is what I have at the moment but it is not working:
int parentFolderWindow = GetDlgItem(parent, 0x440);
//Doesn't work
//ShowWindow((IntPtr)parentFolderWindow, SW_HIDE);
//40961 gathered from Spy++ watching messages when clicking on the control
// doesn't work
//SendMessage(parentFolderWindow, TB_ENABLEBUTTON, 40961, 0);
// doesn't work
//SendMessage(parentFolderWindow, TB_SETSTATE, 40961, 0);
//Comes back as '{static}', am I working with the wrong control maybe?
GetClassName((IntPtr)parentFolderWindow, lpClassName, (int)nLength);
Alternatively, if they do use the parent folder button and go where I don't want them to, I'm able to look at the new directory they land in, is there a way I can force the navigation to go back?
Edit: Added screenshot

//Comes back as '{static}', am I working with the wrong control maybe?
You know you are using the wrong control, you expected to see "ToolbarWindow32" back. A very significant problem, a common one for Codeproject.com code, is that this code cannot work anymore as posted. Windows has changed too much since 2004. Vista was the first version since then that added a completely new set of shell dialogs, they are based on IFileDialog. Much improved over its predecessor, in particular customizing the dialog is a lot cleaner through the IFileDialogCustomize interface. Not actually what you want to do, and customizations do not include tinkering with the navigation bar.
The IFileDialogEvents interface delivers events, the one you are looking for is the OnFolderChanging event. Designed to stop the user from navigating away from the current folder, the thing you really want to do.
While this looks good on paper, I should caution you about actually trying to use these interfaces. A common problem with anything related to the Windows shell is that they only made it easy to use from C++. The COM interfaces are the "unfriendly" kind, interfaces based on IUnknown without a type library you can use the easily add a reference to your C# or VB.NET project. Microsoft published the "Vista bridge" to make these interfaces usable from C# as well, it looks like this. Yes, yuck. Double yuck when you discover you have to do this twice, this only works on later Windows versions and there's a strong hint that you are trying to do this on XP (judging from the control ID you found).
This is simply not something you want to have to support. Since the alternative is so simple, use the supported .NET FileOk event instead. A Winforms example:
private void SaveButton_Click(object sender, EventArgs e) {
string requiredDir = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
using (var dlg = new SaveFileDialog()) {
dlg.InitialDirectory = requiredDir;
dlg.FileOk += (s, cea) => {
string selectedDir = System.IO.Path.GetDirectoryName(dlg.FileName);
if (string.Compare(requiredDir, selectedDir, StringComparison.OrdinalIgnoreCase) != 0) {
string msg = string.Format("Sorry, you cannot save to this directory.\r\nPlease select '{0}' instead", requiredDir);
MessageBox.Show(msg, "Invalid folder selection");
cea.Cancel = true;
}
};
if (dlg.ShowDialog() == DialogResult.OK) {
// etc...
}
}
}

I don't this is going to work. Even if you disable the button they can type ..\ and click save and it will take them up one level. You can't exactly disable the file name text box and maintain the functionality of the dialog.
You'd be better off either using the FolderBrowserDialog and setting it's RootFolder property and asking the user to type the filename in or auto generating it.
If the folder you are wanting to restrict the users to isn't an Environment.SpecialFolder Then you'll need to do some work to make the call to SHBrowseForFolder Manually using ILCreateFromPath to get a PIDLIST_ABSOLUTE for your path to pass to the BROWSEINFO.pidlRoot
You can reflect FolderBrowserDialog.RunDialog to see how to make that call.

Since you want such custom behaviors instead of developing low level code (that is likely yo break in the next versions of windows) you can try to develop your file picker form.
Basically it is a simple treeview + list view. Microsoft has a walk-through .
It will take you half a day but once you have your custom form you can define all behaviors you need without tricks and limits.

How can you programmatically detect if javascript is enabled/disabled in a Windows Desktop Application? (WebBrowser Control)

I have an application which writes HTML to a WebBrowser control in a .NET winforms application.
I want to detect somehow programatically if the Internet Settings have Javascript (or Active Scripting rather) disabled.
I'm guessing you need to use something like WMI to query the IE Security Settings.
EDIT #1: It's important I know if javascript is enabled prior to displaying the HTML so solutions which modify the DOM to display a warning or that use tags are not applicable in my particular case. In my case, if javascript isn't available i'll display content in a native RichTextBox instead and I also want to report whether JS is enabled back to the server application so I can tell the admin who sends alerts that 5% or 75% of users have JS enabled or not.

Thanks to #Kickaha's suggestion. Here's a simple method which checks the registry to see if it's set. Probably some cases where this could throw an exception so be sure to handle them.
const string DWORD_FOR_ACTIVE_SCRIPTING = "1400";
const string VALUE_FOR_DISABLED = "3";
const string VALUE_FOR_ENABLED = "0";
public static bool IsJavascriptEnabled( )
{
bool retVal = true;
//get the registry key for Zone 3(Internet Zone)
Microsoft.Win32.RegistryKey key = Registry.CurrentUser.OpenSubKey(#"Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3", true);
if (key != null)
{
Object value = key.GetValue(DWORD_FOR_ACTIVE_SCRIPTING, VALUE_FOR_ENABLED);
if( value.ToString().Equals(VALUE_FOR_DISABLED) )
{
retVal = false;
}
}
return retVal;
}
Note: in the interest of keep this code sample short (and because I only cared about the Internet Zone) - this method only checks the internet zone. You can modify the 3 at end of OpenSubKey line to change the zone.

If you are having troubles with popups popping up, i've included a solution for you, and if you want to disable/enable javascript on th client machine (or even just read/query if it is enabled/disabled) ive included that answer for you as well, here we go:
Which popup message do you want to disable? If it's the alert message, try this, obviously resolving the window or frame object to your particular needs, I’ve just assumed top-level document, but if you need an iframe you can access it using window.frames(0). for the first frame and so on... (re the JavaScript part)... here is some code, assuming WB is your webbrowser control...
WB.Document.parentWindow.execScript "window.alert = function () { };", "JScript"
You must run the above code only after the entire page is done loading, i understand this is very difficult to do (and a full-proof version hasn't been published yet) however I have been doing it (full proof) for some time now, and you can gather hints on how to do this accurately if you read some of my previous answers labelled "webbrowser" and "webbrowser-control", but getting back to the question at hand, if you want to cancel the .confirm JavaScript message, just replace window.alert with window.confirm (of course, qualifying your window. object with the correct object to reach the document hierarchy you are working with). You can also disable the .print method with the above technique and the new IE9 .prompt method as well.
If you want to disable JavaScript entirely, you can use the registry to do this, and you must make the registry change before the webbrowser control loads into memory, and every time you change it (on & off) you must reload the webbrowser control out and into memory (or just restart your application).
The registry key is \HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\ - the keyname is 1400 and the value to disable it is 3, and to enable it is 0.
Of course, because there are 5 zones under the Zones key, you need to either change it for the active zone or for all zones to be sure. However, you really don't need to do this if all you want to do is supress js dialog popup messages.
Let me know how you go, and if I can help further.

Here is a suggestion - Encode the warning into your webpage as default. Create a javascript that runs on page load which removes that element. The warning will be there when ever javascript is not allowed to run.
It's a long while since I coded client side HTML javascript to interact with the DOM so I may be a little out of date. i.e. you will need to fix details, but I hope I get the general idea across.
<script>
document.getElemntByID("noJavascriptWarning").innerHTML="";
</script>
and in your HTML body
<DIV id="noJavascriptWarning" name="noJavaScriptWarning">Please enable Javascript</DIV>

Silverlight 2 - Download file - IE Blocks file download

I'm having a problem with IE only in my Silverlight application. Since Silverlight 2 doesn't include a mechanism for file downloads I was left to my own devices to come up with a solution. The way I did it was as follows:
HtmlPage.Window.Navigate(new Uri(sb.ToString(), UriKind.Relative));
My StringBuilder contains the relative url with query string to a *.ashx handler on the server that reads the query string, gets some data from the database, and returns an Excel file.
When I do this I get a blocked file download bar in IE only. I understand that this is a new security "feature" in IE and that it is being blocked because it believes that the download wasn't triggered by the user interaction with the web page. The users can choose to allow the download and that setting seems to be remembered for the rest of the session. However next time they open the page it happens again. Even if the site is in the Trusted zone and even if the popup blocker is configured to allow popups for the site.
Does anyone know how to make IE know that the user did in fact request this file?

I had exactly the same problem. The solution for me was to not use HtmlPage.Window.Navigate, but to instead use a HyperlinkButton and dynamically set the NavigateUri property.
Saving and restoring the app state as suggested above didn't work. Well, it did, but it was impossible to determine when it needed to be done and when it didn't. So, ultimately, it didn't really work.
See this discussion on codeplex....
http://slideshow2.codeplex.com/Thread/View.aspx?ThreadId=60242

Try HtmlPage.PopupWindow instead of HtmlPage.Window.Navigate. This has helped me get around IE's "Automatic prompting for file downloads" setting being disabled by default for Internet zone sites.

This is my code solution to open URL for download and override Automatic prompting for file downloads option issue in IE 8.
It also use HyperlinkButton, but all is called from code:
public class BrowserHelper
{
private sealed class HyperlinkButtonCaller : HyperlinkButton
{
public static void OpenUrl(Uri url)
{
var button = new HyperlinkButtonCaller()
{
NavigateUri = url
};
button.OnClick();
}
}
public static void OpenUrl(Uri url)
{
if (url == null)
{
throw new ArgumentNullException("url");
}
HyperlinkButtonCaller.OpenUrl(url);
}
}
BrowserHelper.OpenUrl(new Uri(ClientGlobalInfo.Current.ApplicationUrl, "myhandler.ashx"));

In my case only happended the first time (using IE 7), maybe that happens on your local dev instance?
I think there's not much you can do, even MSDN pages tells you that "a message will appear on top of...", things that could mitigate this:
Warn the user that the message will be shown, then once he clicks the app is reset (Store the current app state in the isolated storage, when you receive the reset reload the app with the settings).
Open a popup, and in the popup include and standard HTML button to download.
HTH
Braulio