Using jQuery in WinForms desktop app? - c#

We have a WinForms desktop application that uses the .NET 2.0 framework WebBrowser control quite extensively for displaying HTML. The HTML may be simple, or quite complicated. It may reside on disk, or it may be written directly to the document property at runtime.
I was wondering if anyone had any experience with using jQuery as a library for such desktop applications. Can i just reference the jquery.js file on disk, and use it just as if it were a web app? Are there any pitfalls that I need to be aware of?

At the end of the day, it's just HTML markup in a browser, treat it as you would if you were working with a page to be viewed in any web browser. jQuery will work just fine assuming you can reference the library from the markup. This would require injecting a script reference into the markup at runtime.
You say that the source may reside on disk or be dynamically generated, I would introduce a pre-loaded step which either loads the file from disk, or generates the markup in memory, then (using string or XML manipulation), inject the jQuery reference and any associated scripts into the markup before populating the WebBrowser document. From there, just let the WebBrowser control do its job.

Related

How to dynamically download and render assembly in a Blazor WASM project?

In my current ASP .Net Core 3.x project using Razor Pages there is a "Reports" page. Each report is a separate assembly on a server. When activated, the client downloads the report's markup (HTML + JS + CSS) through API and renders it dynamically on a page. This works perfectly and makes each report to have it's unique UI with specific validation rules, external requests, etc., since custom JS is used.
Now I'm planning to make a new project using Blazor with the same functionality but this time without JS. Only pure C#.
The only way to render this kind of dynamic content that I've found is through manual RenderTreeBuilder logic. But it seems to be very low-level for this task and that sign saying "These types should be considered unstable and subject to change in future releases" makes me a bit nervous.
So the idea is to dynamically download the entire assembly for the report (or a .zip containing multiple assemblies if needed) and render it's UI with all the logic behind it. It seems that assembly lazy loading could be used for this task, but I'm not entirely sure how to use it for dynamic assembly resolution.
The issue is that this feature requires static information for assemblies that are marked as "lazy" which is not available to me, since reports are separate "plugins" in a server folder. Also it seems that ASP .Net Core hosted solution is also required and my plan was to use static hosting.
In the end I wanted to have a static Blazor SPA, hosted behind any type of a web server (NGINX, Apache, etc.) which requests reports from a API server and renders their UI dynamically with all the logic written in C#.
Any ideas where to start? My thoughts are to go with lazy loading, but not sure how to use that feature for the task.

Serve canned offline web content using the Web Browser control

I'm developing a C# replacement for a legacy VB app for my company. The front end is basically a Web Browser control inside of a Windows form, serving offline content which is sometimes altered to include the user's data. Because there are 100 or more web files in the legacy app, we are going to reuse the web UI from the old application with a new C# wrapper around it, modifying them as needed.
My questions are about how to store and deliver the web content.
Does it make sense to copy the web files to a temporary folder and point the Web Browser control to the file:// address of the temporary folder?
Is there some kind of pre-built offline-friendly server framework that makes more sense than copying the files to a temporary folder?
I have the web source files in my project as resources, but I'm not sure if that is appropriate for my uses. Is it?
The legacy VB implementation alters the web files to inject data using Substring methods; it searches for magic strings and replaces them with the appropriate data. That code smells pretty bad, is there a better, more native data injection strategy I should look at?
Some background:
The data is presented using HTML\CSS\JS and also sometimes XSL.
The browser delivers content that is available at compile time.
I'm going to have to handle some events using c# code when users click on buttons of the page.
I'm free to choose whatever approach is necessary to implement the application.
Hosting
I would probably avoid using a temporary location for the web content it just seems a little crude. If there is no internal linking between your html pages and all the css/js is embedded in one file it may be easier to just use the WebBrowser.DocumentText property.
Another option I have successfully used as a lightweight embedded web server is logv-http, it has a pretty easy to configure syntax. If you want to configure against anything other than localhost it does require administrator privileges but it sounds like everything will be local.
var server = new Server("localhost", 13337);
server.Get("http://localhost:13337" ,(req, res) => res.Write("Hello World!"));
server.Start();
Templating
I think the string replaces aren't necessarily bad depends how many there are and how complicated they are trying to be, but for simple find replace it shouldn't be too hard to manage. If there are lots of replaces wrapping them into a RegEx should help performance.
Storing the web content as embedded resources is probably how I would go that way you can read them out at run-time do you pre-processing and then return either via the the web server method or direct into the DocumentText.

How to deploy an ASP.NET project so that there is no code in the .aspx files?

I've recently become the maintainer of an ASP.NET web project. In the course of deploying some changes, we noticed that at some point the way the project deploys has changed. The project is a web application project. Currently, when I "Publish" it to my local machine, I can open the various .aspx files and see some code--a little ASP, mostly JavaScript, but the majority of the code seems to be compiled into a .dll.
What we would like is to build and deploy this application so that there is no code in the .aspx files--this is how it used to work, before the previous dev stopped maintaining it. There should be no code in the .aspx files at all, just a reference to the compiled .dll files.
Does anyone know what I'm talking about and how to set it up?
EDIT If it helps, it looks like the older version of the app just had text in the .aspx files that said "This is a marker file generated by the precompilation tool, and should not be deleted!" That is what I'm going for.
If you want to do this for your Website just Pre-compile your project for deployment only. You can check out the exact steps in this MSDN article
This will move all the codebehind files into the .dll and create .aspx.compiled files as pointers to the compiled versions in the .dll. Sounds like thats what was being done before.
The code shouldn't be visible from the client's browser.
Any code that in a code-behind will get compiled to a .dll which the pages in the application would reference. The actual code-behind files shouldn't get published with the .aspx files.
.NET code within the .aspx files shouldn't be visible on the client-side because it has no use on the client-side. It should be executed on the server-side to render HTML output to the client. If the .NET code is visible on the client-side in this case, it means the server isn't executing it and the site is essentially broken.
JavaScript code, of course, needs to be visible on the client-side. There are ways to obfuscate it, but the browser needs to see it in order to execute it. So in this case that code should be developed with the full understanding that it is publicly visible and nothing proprietary or compromising should be included in it.
JavaScript code has to exist on the client side, so that has to be on the server. Inline ASP code? I'd look into rewriting that into .NET.
In order to achieve no code in the .aspx files you need to write all the code in the code behind. You use the asp.net events in the life cycle to perform the generation of client code. For example, dynamically generated HTML and javascript could be generated in the Page_Load and written out as a Response. Any asp.net that you may use needs to be dynamically generated in the code behind with everything else.
You will still push HTML and javascript to the client, but all the code will be in assemblies/dll's except the header info in the aspx pages. I have only done this in the context of a web service ( RESTful) where I pushed out XML to an iPhone for consumption. Doing it for a full website may prove to be quite cumbersome.
It doesn't make sense to do this if the concern is security. Moving the code to an assembly is not much more secure than the aspx page. If the concern is to remain concise, I suggest moving to ASP.NET MVC 3.

Display HTML in a silverlight application

I need to display HTML in my silverlight application and cannot find a way of doing it. I cannot use the web browser control as it needs to be able to run in or out of a browser.
Does anyone know of a good way to do this, because all I can think of doing at the moment is running replace methods on the text to just replace the tags with C# equivalents eg(<br /> to \n).
The way I do it is to check if the application is running inside the browser and change the means of display accordingly. If running inside the browser, I overlay the application with an IFrame, as I describe in this article: http://www.silverlightshow.net/items/Building-a-Silverlight-Line-Of-Business-Application-Part-6.aspx. Otherwise, I use the WebBrowser control. I have a control which does this all for you in the source code that accompanies my book, which is downloadable from the Apress website here: http://www.apress.com/book/downloadfile/4638.
Hope this helps...
Chris
I believe what you are looking for is HTML Bridge.
Edit I'm am actually now unsure if you'll still have access to javascript if you're running this OOB. I'm going to look into this some more and will further update. I'll still leave the answer up though for reference.
Second Edit Here is what I've found. HTML Bridge is disabled when you run silverlight out of browser. This disables access to the HTML DOM as well as Javascript. However, according to a comment on this site:
HTML Bridge is not available when you first install a OOB app. But you CAN force it if you modify the index.html in the folder where the app is installed just adding the enablehtmlaccess parameter.
It works!
You can even create dynamic HTML elements using the well-known methods of the HtmlPage class. You can even open a new browser window with the Navigate() method and its "_blank" parameter.
Keep in mind this information was posted about SL 3. Its possible that this may have changed, but I doubt it. So it seems that what you may want to do is build a script into the startup of your SL app that detects whether or not your app is running out of browser. If it is then you may want to have some script to call that can modify this file for you.
There recently was a similar question.
I posted a link there to an implementation that parses and displays HTML inline in Silverlight. Of course, it will work only with simple HTML, but maybe you can expand it to your needs.

C# code for saving an entire web page? (with images/formatting)

I've been struggling to find an exmample of some C# code (I'm using C# Visual Studio 2008 Express) that can programmatically save an entire web page (given a URL) including the images and formatting (e.g. CSS). The intention is that in a subsequent phase I'd ship this off (not sure how yet) so it could be viewed later via a browser.
Is there an example of the most simple approach (leveraging the .NET Framework methods) to save an entire web page? Saving as one page with a subdirectory for images, or otherwise. Basically the same as what you get with browsers when you say "save entire web page".
The simplest way is probably to add a WebBrowser Control to your application and point it at the page you want to save using the Navigate() method.
Then, when the document has loaded, call the ShowSaveAsDialog method. The user can then save the page as a single file, or a file with images in a subdirectory.
[Update]
Having now noticed "programatically" in your question, the above approach is not ideal as it requires either user involvement or delving into the Windows API to send input using SendKeys or similar.
There is nothing built-in to the .NET Framework that does all of what you ask.
So my approach revised would be:
Use System.NET.HttpWebRequest to get the main HTML document as a string or stream (easy).
Load this into a HTMLAgilityPack document where you can now easily query the document to get lists of all image elements, stylesheet links, etc.
Then make a separate web request for each of these files and save them to a subdirectory.
Finally update all relevent links in the main page to point to the items in the subdirectory.
In effect you would be implementing a very simple web browser. You may run into issues with pages that use JavaScript to dynamically alter or request page content, but for most pages this should give acceptable results.
From code Project: ZetaWebSpider
It's definitely not elegant, but you could navigate a System.Windows.Forms.WebBrowser to the URL and then call its ShowSaveAsDiagog() method to save the page.

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