Develop Reference

C# WebBrowser turn off jquery popups

I have an application that uses WebBrowser control to navigate from page to page, on some pages I get a leaving popup asking me if that's what I want to do.. this stops the whole further execution until I press "Leave" or "Stay".. How can I disable them?
What I've tried so far were these actions:
a) setting window.onbeforeunload = null;
b) setting alert, confirm, prompt to an empty function
c) settin suppressErrorMessages to true
but even so, I still get the nasty message in the end.
I mostly relied on this answer:
How to update DOM content inside WebBrowser Control in C#?
But so far without a success.
The alerts seem to be jQuery alerts because they have custom texts (instead of OK Cancel, they have Stay Leave)..
Any help hugely appreciated!!

The webbrowser control uses IE internally and IE has a prompt if you've filled out a form asking you if you really want to leave the page (thereby losing the content you've filled out) perhaps that's what you're seeing?
i'm just shooting from the hip here but you could try clearing all inputs before navigating.

C# Setting InnerHtml to "" for an element which is updated by server causes element to stop updating

I have a C# Windows Forms Application with a webBrowser within it. It visits a Wikia chatroom, where it then locates the element which contains the chat output. This element looks like:
<div style="" id="Chat_XXXXX" class="Chat">
<ul>
(chat text)
</ul>
</div>
The purpose of the program is to retrieve the chat text every once in a while for logging purposes. This is easily done by parsing the "InnerHtml" of the "Chat_XXXXX" element. However, I also need to clear the text from the window when I do this (for various reasons, I cannot leave the text in the window). I figured I would just erase the chat text portion of the element, as this is how it is done with a handy javascript file called "chat hacks" for Wiki chat (here). Or at least, I think that's how it does it. If you look at the function "clearWindow" in that file, you can see what it does:
NodeChatController.prototype.clearWindow = function() {
this.viewDiscussion.chatUL.html('');
this.inlineAlert(i18n['cleared']);
}
I have tried setting the InnerHtml of "Chat_XXXXX" using the following three strings (not all at the same time, of course):
HtmlDocument document = webBrowser1.Document;
document.GetElementById("Chat_XXXXX").InnerHtml = ""
document.GetElementById("Chat_XXXXX").InnerHtml = "<ul></ul>"
document.GetElementById("Chat_XXXXX").InnerHtml = "<ul><li class=\"inline-alert\"> Window cleared. </li></ul>"
However, although these clear the window (and in the case of the last one prints a message), the chat no longer updates as new messages show up. The only fix is to reload the page, which isn't an option, because reloading the page brings in a whole load of chat history (which I'm trying to avoid). I've also tried importing that javascript mentioned above into the page using:
HtmlElement head = webBrowser1.Document.GetElementsByTagName("head")[0];
HtmlElement scriptEl = webBrowser1.Document.CreateElement("script");
scriptEl.SetAttribute("type", "text/javascript");
scriptEl.SetAttribute("src", "https://db.tt/66q8UQbY");
head.AppendChild(scriptEl);
This javascript creates a button which clears the chat window. The button clears the window just fine, but again, the chat no longer updates. I know this button works correctly without stopping further incoming chat in "regular" browsers (Chrome, Firefox, Opera, etc). I've used it many times, and the script itself is quite popular in the Wikia community. I've already followed the steps here: "WPF WebBrowser Control - position:fixed Element jumps while scrolling (Windows 8)" to get the browser to act as close as it can (?) to Internet Explorer. I've already checked the Body field of the document after altering the InnerHtml to make sure that my replacements didn't alter anything important. Just for clarity, here's an example of what is contained in the (chat text) portion of my original example:
<li class="you" data-user="UserNameHere" id="entry-c812">
...avatars and junk...
<span class="message">hello</span>
</li>
I honestly have no idea what could be causing the chat element to stop updating after it has been edited (especially since it works outside of this program), so I don't know what information to include. Whatever you need, I'll provide it. Here's the javascript from Wikia which generates the chat output window: chat_js2. Look for "Chat_" to find the part which originally generates the window. I don't know where the output is updated in that file though.

How Internet Explorer Prepare Print Preview window

I am wondering how Internet Explorer, Mozilla Firefox or any other browser generate print preview window of an web page loaded into the browser.
The preview image will have various changes such as banners and adv are removed, will have white background and black text and etc.
We would like implement similar print preview window using C# WebBrowser control and i don't want to use default browser Print preview feature such as ExecWB command or any other.
Please give us some light on this.
Thanks,
Ramanand Bhat.

You could try to alter the styles by accessing and modifying the HTMLDocument LINK elements.
HtmlDocument document = WebBrowser1.Document;
foreach (HtmlElement element in document.GetElementsByTagName("LINK"))
{
string cssMedia = element.GetAttribute("Media");
if (cssMedia == "print")
element.SetAttribute("Media", "screen"); //sets print styles to display normally
else
element.SetAttribute("Media", "hidden"); //hides normal styles
}
This will change your print-styles to display in screen view (i.e. as a normal stylesheet without having to use the print-preview window) and your screen-styles to not be shown (as they don't have a Media type of screen anymore)
This is sample code so doesn't have any error checking. It might also have some syntax errors but it should be a start to achieve your goal.

To print a screen you need to set up a call to window.print() in javascript.
Print screen
It will then use whatever css you have assigned as 'print' in the page to render the page as a preview

As far as I know, the banners, advertisements, et cetera are not removed by the browser during a print preview. CSS governs the appearance when the media is print.

Retrieve Selected Text from a Web Browser Control in a

Here's what I am trying to do:
Select text from a webpage I pulled up using my web browser control.After clicking a button while this text is still selected I would like a message box to pop-up displaying the text that was highlighted by the user. How do I get this functionality to work in my wpf application?
I think I'm on the right track using mshtml but I get an error that says:
Error HRESULT E_FAIL has been returned from a call to a COM component.
This error will happen even when I try something small on the document like changing the title.
The code is below:
IHTMLDocument2 doc = (IHTMLDocument2)this.webBookText.Document;
doc.title = "l";

Well, for starters it would be a lot simpler to use WebBrowser than mshtml (note that you can still host WebBrowser in WPF) - this will certainly let you do simple things a lot easier:
webBook.Document.Title = "foo";
However, I can't see anything there that would let you work with selections very easily...
You can get the selected element with .Document.ActiveElement, but this is the entire element - not the selected portion.

Figured it out that error was because this wasn't in my form class

How do I insert text into a textbox after popping up another window to request information?

I have an asp.net web page written in C#.
Using some javascript I popup another .aspx page which has a few controls that are filled in and from which I create a small snippet of text.
When the user clicks OK on that dialog box I want to insert that piece of text into a textbox on the page that initial "popped up" the dialog/popup page.
I'm guessing that this will involve javascript which is not a strong point of mine.
How do I do this?

You will have to do something like:
parent.opener.document.getElemenyById('ParentTextBox').value = "New Text";

What you could do is create an ajax modal pop-up instead of a new window. The semantic and aesthetic value is greater not to mention the data-passing is much easier.
http://www.asp.net/ajax/ajaxcontroltoolkit/samples/modalpopup/modalpopup.aspx