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Re: Deny access to a datatable while in use from another object

Richard Andrew x6414-Jun-11 20:12

Richard Andrew x64

14-Jun-11 20:12

I know that MySQL has commands for locking tables and even rows. Perhaps your database has that as well.

What database are you using?

The difficult we do right away...
...the impossible takes slightly longer.

Re: Deny access to a datatable while in use from another object

jschell15-Jun-11 9:04

jschell

15-Jun-11 9:04

MAW30 wrote:
I do not want to be able to read the dt while incoming info has been processed.

Why don't you put the data into an alternative table (or tables) then process it in place and then once you are done, post it all at once to the final tables?

That precludes error conditions that end up looking a dependent resource for long periods of time.

Parsing HTML of some website using C Sharp.

shivamkalra14-Jun-11 15:35

shivamkalra

14-Jun-11 15:35

Hello everyone,

I'm working on a small hobby project. I'm making a web crawler for a particular website to extract some useful information from it. I've written information extraction algorithms but I'm completely new to HTTP response stuff. I'm using a HttpWebResponse class of .Net to get the source code of a webpage in form of StreamReader. Now, I'm wondering if I should process each line of stream or I should convert whole streamReader to a string and then process that. Let say, I'm looking for string that should be able to extract .mp3 links on webpage using regex then is it possible that a single link is on two differnt lines of StreamReader, look at the code below..

            string url = "http://songs.pk";
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            StreamReader sr = new StreamReader(response.GetResponseStream());

            string line;
            while ((line = sr.ReadLine()) != null)
            {
// Add some processing code here
                Console.Read();
                Console.WriteLine(line);
            }

Now can I add some regex matching code here..will this code make sure that it will be able to extract all the .mp3 links from this website? Or should I convert the StreamReader to string and then use regex matching on that string?

I'm sorry, if I'm misunderstanding about StreamReader here, but I need some suggestions to parse the source code of a website. I've searched articles and Google but I'm unable to find something that could help me. Any articles, links or suggestions would be appreciated.

Thanks
Shivam Kalra

Re: Parsing HTML of some website using C Sharp.

JV999914-Jun-11 21:55

JV9999

14-Jun-11 21:55

Your code is fine. You will read the HTML code line-by-line from the page and you can process the whole html page line by line. This is a pretty common scenario. You can use a regex to determine if the value from the line-field contains what you are searching for Smile | :)

Re: Parsing HTML of some website using C Sharp.

BobJanova15-Jun-11 0:29

BobJanova

15-Jun-11 0:29

I would read the whole stream (to get the full page content) and use your regexes on that. The streaming is very useful for large downloads, but a web page is easily small enough to work on in memory. StreamReader.ReadToEnd is the easiest way to do that.

Re: Parsing HTML of some website using C Sharp.

GenJerDan15-Jun-11 3:59

GenJerDan

15-Jun-11 3:59

You could also use the HTMLDocument, IHTMLElementCollection, and IHTMLElement to read each tag found in the response and grab the innerHTML if it's a tag you're interested in.

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Call Web Service Without Reference?

Kevin Marois14-Jun-11 12:02

Kevin Marois

14-Jun-11 12:02

Is it possible to call a Web Service from C# without first adding a reference to the WS in your project? All the examples I see require a reference. An example would be great.

Thanks

Everything makes sense in someone's mind

Re: Call Web Service Without Reference?

Kevin Marois14-Jun-11 13:13

Kevin Marois

14-Jun-11 13:13

NM. Found this

Call a Web Service Without Adding a Web Reference[^]

Everything makes sense in someone's mind

Re: Call Web Service Without Reference?

PIEBALDconsult14-Jun-11 14:11

PIEBALDconsult

14-Jun-11 14:11

What's a project?

How to learn Web Based Apps?

Software200714-Jun-11 5:44

Software2007

14-Jun-11 5:44

Hello,

Sorry, if its the wrong place to post. I have been doing Embedded Systems (lower level) development on Linux/Windows, in Generic C++ and Visual C++ for the last 5 years or so. I am trying to switch my focus to the new stuff as far as Web applications and latest stuff out there. I would like to do Web Services (middle and Back end not so much web site development). I have started learning C# (winforms) which isn't much different from C++, I guess I can pick up WPF as well. Currently, I am working in robotics and automations which is database driven development, may be its one step closer to what I need.

Can you please give me good tips of how you might approach this? and what topics to really focus on so I might need(may be ASP.net, WCF, DataBases...etc) that can make me a lot more marketable for employers?

Thanks

Re: How to learn Web Based Apps?

#realJSOP14-Jun-11 7:19

#realJSOP

14-Jun-11 7:19

Software2007 wrote:
Sorry, if its the wrong place to post.

It is, and there's really no excuse for it. You can obviously read, which means you should have EASILY noticed the forum Titled "Web Development" in the menu you had to use to get to THIS forum.

To answer your question, the only real way to learn a new technology is to actually use that technology, and always remember - google is your friend. Create a VERY simple web service and then write a bunch of different clients to connect to it. I'd also put some time into learning about WCF.

Part of writing web services is correctly deploying them, and using them from a remote machine. This means you're going to need another box entirely, or a single machine with enough juevos to run a VM running IIS alongside your own native development deskop. I'm lucky enough to have a 2nd box so I don't have to mess with the sometimes messy bridging of netowrk adapters necessary to be able to communicate with the OS on the virtual desktop.

WPF isn't a back-end technology, and requires the same knowledge to hook an app up to a web service. However, Silverlight is a completely different animal, and it requires still more special knowledge to get it working with a web service.

".45 ACP - because shooting twice is just silly" - JSOP, 2010
-----
You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
-----
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Re: How to learn Web Based Apps?

Software200714-Jun-11 8:07

Software2007

14-Jun-11 8:07

Thanks for the reply. I am still not too familiar with the architecture, so in a banking example, where clients log on to ask for balances and review account summary, what would be the wcf service, clients? Will the clients be any wpf/winform apps hooking up with the wcf service?

Is this a good example for me to emulate so I can pick up how these thing work?

Thanks

Re: How to learn Web Based Apps?

l a u r e n14-Jun-11 8:59

l a u r e n

14-Jun-11 8:59

ok so in a classic web service situation you have an API that you can talk to from client apps (be they web site front ends, mobile apps, desktop apps, or whatever)

the API will be a REST API type thing (basically means you can call it via a URI like a web page) and typically you will get back either XML or JSON (depending on what problem domain you are dealing with)

so you would write essentially a web site that has no face and doesn't output any html as such ... and then you implement the clients who make requests (like custom mini browsers effectively) and get responses in whatever you decided to use (XML,JSON,etc) ... then your clients have to decide how to cache / display / save the data returned from the web service

this is a very simplistic overview but hopefully it isn't insulting or too stupid to be useful as a starting point

Smile | :)

"mostly watching the human race is like watching dogs watch tv ... they see the pictures move but the meaning escapes them"

Re: How to learn Web Based Apps?

Roger Wright14-Jun-11 21:27

Roger Wright

14-Jun-11 21:27

Simplistic, yes, but insulting it isn't. It's an excellent minimalist recommendation for implementation that makes perfect sense. Very efficient! Big Grin | :-D

Will Rogers never met me.

Re: How to learn Web Based Apps?

Mark Salsbery17-Jun-11 10:38

Mark Salsbery

17-Jun-11 10:38

John Simmons / outlaw programmer wrote:
Silverlight is a completely different animal, and it requires still more special knowledge to get it working with a web service.

Just for the record, both WPF and Silverlight are client-end technologies and are pretty much identical in how they work with web services, aside from some limitations in Silverlight with its smaller .NET runtime... Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: How to learn Web Based Apps?

#realJSOP18-Jun-11 1:08

#realJSOP

18-Jun-11 1:08

Silverlight requires "special knowledge" if you're working on a secure site. It took me a couple of weeks to figure how how to put that jigsaw puzzle together...

Re: How to learn Web Based Apps?

Lutosław14-Jun-11 21:47

Lutosław

14-Jun-11 21:47

I was very reluctant to start learning ASP .NET because I regarded coding in HTML as awful and disgusting. But I have switched from WinForms to WPF recently and I found it a right move. Since in WPF you code XML, it was easier for me to create my first ASP page which happened two weeks ago or so.

Greetings - Jacek

Re: How to learn Web Based Apps?

Software200715-Jun-11 10:28

Software2007

15-Jun-11 10:28

Great. I am not sure if I do need to learn ASP.net or any xml/html coding, since I do not want to do front end website design. I am mostly interested in the middle and backend of web development. Do you think I need to know ASP.net?

Re: How to learn Web Based Apps?

Lutosław15-Jun-11 12:16

Lutosław

15-Jun-11 12:16

Software2007 wrote:
Do you think I need to know ASP.net?

IMHO yes -- to fully understand how it works. But this is a question for proffesionals not me.

Greetings - Jacek

How to retrieve single row from datatable?

SRKSHOME14-Jun-11 3:47

SRKSHOME

14-Jun-11 3:47

Hi,

I have a datatable in which i know one value of a column. How to get entire row of that particular data?

Thanks

Re: How to retrieve single row from datatable?

Blue_Boy14-Jun-11 3:58

Blue_Boy

14-Jun-11 3:58

You can use Filtering direct on DataTable.[^]

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Split string with Regex

Ronald de Boer13-Jun-11 17:37

Ronald de Boer

13-Jun-11 17:37

Hi,

I need to split a large string and split that splitted string again. I have the following string:

root
{
  stringB = 
  {
    "key": "value",
    "key": "value",
    "StringC":
    {
      "key": "value",
      "key": "value",
      "key": "value",
      "key": "value",
    }
    "StringD": "value",
    "StringE":
    {
      "key": "value",
    }
  }
}

The result I actually want is something like this:
string[] AllStrings = StringB,StringC,StringD,StringE

Is there a way to do this? I used Regex.Split option.
Thanks in advance!

Re: Split string with Regex

PIEBALDconsult13-Jun-11 18:24

PIEBALDconsult

13-Jun-11 18:24

That doesn't look regular enough. And try the Regex forum.

Re: Split string with Regex

Richard MacCutchan13-Jun-11 21:50

Richard MacCutchan

13-Jun-11 21:50