Develop Reference

Cannot access internal property 'ConvertedHtmlElementSelector' here

I am using HiQPdf Free to generate PDFs from an URL. I noticed in their documentation, you can simply grab a specific element instead of the whole page. It would go something like this:
HtmlToPdf htmlToPdfConverter = new HtmlToPdf();
htmlToPdfConverter.ConvertedHtmlElementSelector = "#logo";
htmToPdfConverter.ConvertUrlToFile("https://your-website.com/", "/path/to/pdf.pdf");
However, when I do the htmlToPdfConverter.ConvertedHtmlElementSelector in my code, it tells me this error:
Cannot access internal property 'ConvertedHtmlElementSelector' here
Could this be because it's a paid only feature? That seems like the only obvious reason, however, I haven't been able to find any source on that.

Converting only a region of the HTML page to PDF is a feature of the full version and it is not available in the free version. There is an example for this feature with C# and VB.NET code samples at http://www.hiqpdf.com/demo/ConvertHtmlRegionToPdf.aspx

convert VB code to C#

I'm a beginner in programming and i would like to know how can i translate the following code into C#
Dim arrayAlumnos(ds.Tables(0).Rows.Count - 1) As Registro

To preserve the array idea I'd probably write it like:
var arrayAlumnos = new Registro[ds.Tables[0].Rows.Count];
But you could say this too:
Registro[] arrayAlumnos = new Registro[ds.Tables[0].Rows.Count];
But ChaosPandion is right... a List is what you'd want to use most likely.

You should be using a list so I think this is the proper translation.
List<Registro> students = new List<Registro>();

you'll probably have a lot of one off questions like this going through your travels of conversion, might want to take a look at:
http://msdn.microsoft.com/en-us/library/aa288436(v=vs.71).aspx
The basic idea behind the creation in C# is...
~ObjectType~ ~varName~ = new ~type~(~implement a type constructor here~);
anything in between ~~s you'll need to plug in the appropriate information. For your case it would likely be:
Registro[] arrayAlumnos = new Registro[ds.Tables[0].Rows.Count - 1];
Kind of hard since it's a different spoken language but based on your variable name i'm guessing it's an array, though as others pointed out it could easily be created as a list.

FYI, if you want to convert a lot of code from VB to C#, you can use the ILSpy disassebler. You can do this even if you don't have the original VB code. Do this:
Compile the VB code into a *.exe or a *.dll.
Open the *.exe or *.dll file in ILSpy.
In the language dropdown, select VB. (It's values are C#, VB, and MSIL).

c# - beginner wants to add code on the run from a string containing a math function

I learned basic algorithms on visual C# in highschool, and I made a simple code that numerically integrates a math function within given limits.
I want to be able to change the function the code integrates without actually editing the code, so I googled it for a while and found a lot of articles about how to do it. I tired to understand it but the problem is I can't understand any of what's written there because it's too much above my level.
I need a code that can add code on the run from a string containing a math function, that can accept a variable, log, ln, powers, sin, cos, tan and maybe pi and e, that is ready in a friendly "copy-paste" format, followed by instructions on where to paste it, and how to connect it to my code. To clarify:
I want to take something like this:
string s = "Sqrt(ln(1 + x ^ 2))";
and make it like this:
double x = 0;
double y = Math.Sqrt(Math.Log(1 + Math.Pow(x,2)));
I know it's a pretty annoying request and if it's not the right place to ask such a thing I apologize in advance.

This is actually fairly difficult to do in a language like C#, as it's statically compiled.
A good alternative would be to use an expression parsing library, such as NCalc. This library would allow you to create the expression (your string), parse it, and extract the result.

How to translate website in another language?(ASP .NET , c#)

I have developed a large business portal. I just realized I need my website in another language. I have researched the solutions available like
Used third party control on my website. (Does fit in my design. Not useful regarding SEO point of view. Dont want to show third party brand names.)
Create Resource files for each language.( A lot of work required to restructure pages to use text from resource files. What about the data entered by the user like Business Description. )
Are there any Other options available.
I was thinking of a solution like a when a page is created on server side then I could translate it before sending back to client. Is there any way I can do that?(to translate everything including data added from databases or through a code. And without effecting design. )

If you really need to translate your application, it's going to take a lot of hard, tedious work. There is no magic bullet.
The first thing you need to do is convert your plain text in your markup to asp:Localize controls. By using the Localize control, you can leave your existing <span> tags in place and just replace the text inside of them. There's really no way around this. Visual Studio's search and replace supports regular expression matching that may help you with this, or you can use Resharper (see below).
The first approach would be to download the open source shopping application nopCommerce and see how they handle their localization. They store their strings in a database and have a UI for editing languages. A similar approach may work well for you.
Alternatively, if you want to use Resource Files, there are two tools that I would recommend using in addition to Visual Studio: Resharper 5 (Localization Features screencast) and Zeta Resource Editor. These are the steps I would take to accomplish it using this method:
Use the "Generate Local Resource" tool in visual studio for each page
Use Resharper's "Move HTML to resource" on the text in your markup to make them into Localize controls.
Use Resharper to search out any localizable strings in your code behind and move them to the resource file as well.
Use the Globalization Rules of Code Analysis / FXCop to help find any additional problems you might face formatting numbers, dates, etc.
Once all text is in the resx files, use Zeta Resource Editor to load up all of your resx files, add new languages, and export for translation (or auto translate if you're brave enough).
I've used this approach on a site translated into 8 languages (and growing) with dozens of pages (and growing). However, this is not a user-editable site; the pages are solely controlled by the programmers.

a large switch case? use a dictionary/hashtable (seperate instance for each a language), it is much, much more effective and fast.

To Convert The Page To Arabic Language Or Other Language .
Go to :
1-page design
2-Tools
3-Generate Local Resource
4-obtain "App_LocalResources" include "filename.aspx.resx"
5-copy the file and change the name to "filename.aspx.ar.resx" to convert the page to arabic language or other .
hope to helpful :)

I found a good solution, see in http://www.nopcommerce.com/p/1784/nopcommerce-translator.aspx
this project is open source and source repository is here: https://github.com/Marjani/NopCommerce-Translator
good luck

Without installing any 3rd party tool, APIs, or dll objects, I am able to utilize the App_LocalResources. Although I still use Google Translate for the words and sentences to be translated and copy and paste it to the file as you can see in one of the screenshots below (or you can have a person translator and type manually to add). In your Project folder (using MS Visual Studio as editor), add an App_LocalResources folder and create the English and other language (resx file). In my case, it's Spanish (es-ES) translation. See screenshot below.
Next, on your aspx, add the meta tags (meta:resourcekey) that will match in the App_LocalResources. One for English and another to the Spanish file. See screenshots below:
Spanish: (filename.aspx.es-ES.resx)
English: (filename.aspx.resx)
.
Then create a link on your masterpage file with a querystring that will switch the page translation and will be available on all pages:
<%--ENGLISH/SPANISH VERSION BUTTON--%>
<asp:HyperLink ID="eng_ver" runat="server" Text="English" Font-Underline="false"></asp:HyperLink> |
<asp:HyperLink ID="spa_ver" runat="server" Text="Español" Font-Underline="false"></asp:HyperLink>
<%--ENGLISH/SPANISH VERSION BUTTON--%>
.
On your masterpage code behind, create a dynamic link to the Hyperlink tags:
////LOCALIZATION
string thispage = Request.Url.AbsolutePath;
eng_ver.NavigateUrl = thispage;
spa_ver.NavigateUrl = thispage + "?ver=es-ES";
////LOCALIZATION
.
Now, on your page files' code behind, you can set a session variable to make all links or redirections to stick to the desired translation by always adding a querystring to urls.
On PageLoad:
///'LOCALIZATION
//dynamic querystring; add this to urls ---> ?" + Session["add2url"]
{
if (Session["version"] != null)
{
Session["add2url"] = "?ver=" + Session["version"]; //SPANISH version
}
else
{
Session["add2url"] = ""; // ENGLISH as default
}
}
///'LOCALIZATION
.
On Click Events sample:
protected void btnBack_Click(object sender, EventArgs e)
{
Session["FileName.aspx"] = null;
Response.Redirect("FileName.aspx" + Session["add2url"]);
}
I hope my descriptions were easy enough.

If you don't want to code more and if its feasible with google translator then You can try with Google Translator API. you can check below code.
<script src="http://translate.google.com/translate_a/element.js?cb=googleTranslateElementInit"></script>
<script>
function googleTranslateElementInit() {
$.when(
new google.translate.TranslateElement({pageLanguage: 'en', includedLanguages: 'en',
layout: google.translate.TranslateElement.FloatPosition.TOP_LEFT}, 'google_translate_element')
).done(function(){
var select = document.getElementsByClassName('goog-te-combo')[0];
select.selectedIndex = 1;
select.addEventListener('click', function () {
select.dispatchEvent(new Event('change'));
});
select.click();
});
}
$(window).on('load', function() {
var select = document.getElementsByClassName('goog-te-combo')[0];
select.click();
var selected = document.getElementsByClassName('goog-te-gadget')[0];
selected.hidden = true;
});
</script>
Also, Find below code for <body> tag
<div id="google_translate_element"></div>

It will certainly be more work to create resource files for each language - but this is the option I would opt for, as it gives you the opportunity to be more accurate. If you do it this way you can have the text translated, manually, by someone that speaks the language (there are many companies out there that offer this kind of service).
Automatic translation systems are often good for giving a general impression of what something in another language means, but I would never use them when trying to portray a professional image, as often what they output just doesn't make sense. Nothing screams 'unprofessional!' like text that just doesn't make sense because it's been automatically translated.

I would take the resource file route over the translation option because the meaning of words in a language can be very contextual and even one mistake could undermine your site's credibility.
As you suggest Visual Studio can generate the meta resource file keys for most controls containing text but may leave you having to do the rest manually but I don't see an easier, more reliable solution.
I don't think localisation is an easy-to-automate thing anyway as text held in the database often results in schema changes to allow for multiple languages, and web HTML often need restructuring to deal with truncated or wrapped label and button text because, for example, you've translated into German or something.
Other considerations:
Culture settings - financial delimitors, date formats.
Right-to-left - some languages like arabic are written right to left meaning that the pages require rethinking as to control positioning like images etc.
Good luck whatever you go with.

I ended up doing it the hard way:
I wrote an extension method on the string class called TranslateInto
On the Page's PreRender method I grab all controls recursively based on their type (the types that would have text)
Foreach through them and text.TranslateInto(SupportedLanguages.CurrentLanguage)
In my TranslateInto method I have a ridiculously large switch statement with every string displayed to the user and its associated translation.
Its not very pretty, but it worked.

We work with a Translation CAT tool (Computer Assisted Translation) called MemoQ that allows us to translate the text while leaving all the tags and coding in place. This is very helpful when the order of words change when you translate from one language to another.
It is also very useful because it allows us to work with translators from around the world, without the need for them to have any technical expertise. It also allows us to have the translation proof read by a second translator.
We use this translation environment to translate html, xml, InDesign, Word, etc.

I think you should try Google Translate.
http://translate.google.com/translate_tools
Very easy and very very effective.
HTH

Getting the Windows System Error Code title/description from its hex number

I'm messing around with some windows functions using p/invoke. Occasionally, I get an error code that is not ERROR_SUCCESS (such an odd name).
Is there a way to look these up within the program? Forexample, if I get error 1017. Can I tell the user
The system has attempted to load or
restore a file into the registry, but
the specified file is not in a
registry file format.
(ERROR_NOT_REGISTRY_FILE: 0x3F9)
Instead of
Error Code: 1017

I'm not sure if there's a niifty .NET wrapper, but you could call the FormatMessage API using P/Invoke.
See this answer for how it would normally be called from native code. Though the question refers to grabbing error codes from HRESULTs, the answer also applies for retreiving codes from the regular OS error codes coming from GetLastError/GetLastWin32Error).
EDIT: Thanks Malfist for pointing me to pinvoke.net, which includes alternative, managed API:
using System.ComponentModel;
string errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
Console.WriteLine(errorMessage);

You could take the defines from winerror.h at Rensselaer Polytechnic Institute, and put them into an Enum:
public enum Win32ErrorCode : long
{
ERROR_SUCCESS = 0L,
NO_ERROR = 0L,
ERROR_INVALID_FUNCTION = 1L,
ERROR_FILE_NOT_FOUND = 2L,
ERROR_PATH_NOT_FOUND = 3L,
ERROR_TOO_MANY_OPEN_FILES = 4L,
ERROR_ACCESS_DENIED = 5L,
etc.
}
Then if your error code is in a variable error_code you would use :
Enum.GetName(typeof(Win32ErrorCode), error_code);

I landed on this page while in search of a managed alternative to calling FormatMessage through P/Invoke.
As others have said, there is no way to get those capitalized, underscored names, short of looking them up in winerror.h, which I have seen reproduced online in various places where I landed in the course of searching for information about resolving specific status codes. A quick Google search, for winerror.h, itself, uncovered a page, at Rensselaer Polytechnic Instutute, where someone has helpfully extracted the #define statements from it.
Looking at it gave me an idea; I think there may be a way to get there, working from the source code of winerror.h, which I have, as part of the Windows Platform SDK that ships with every recent version of Microsoft Visual Studio.
Right now, I am in the middle of sorting out a pressing issue in the .NET assembly that brought me to this page. Then, I'll see what I can cobble together; this kind of challenge is right up my alley, and somebody threw down a gauntlet.

Yes there's a function that does that but I don't remember what it is. In the mean time, you can use the error lookup tool (Tools->Error Lookup) to see what a particular code means from within Visual Studio.