I have a .html page that just has 5 characters on it (4 numbers and a period).
The only way I know of is to make a webbrowser that navigates to a URL, then use
browser.GetElementByID();
However that uses IE so I'm sure it's slow. Is there any better way (without using an API, something built into C#) to simply visit a webpage in a fashion that you can read off of it?
Try these 2 lines:
var wc = new System.Net.WebClient();
string html = wc.DownloadString("http://google.com"); // Your page will be in that html variable
It appears that you want to download a url, parse it as html then to find an element and read its inner text, right? Use nuget to grab a reference to HtmlAgilityPack, then:
using(var wc = new System.Net.WebClient()){
string html = wc.DownloadString("http://foo.com");
var doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(html);
var el = doc.GetElementbyId("foo");
if(el != null)
{
var text = el.InnerText;
Console.WriteLine(text);
}
}
Without using any APIs? You're in the .NET framework, so you're already using an abstraction layer to some extent. But if you want pure C# without any addons, you could just open a TCP socket to the site and download the contents (it's just a formatted string, after all) and read the data.
Here's a similar question: How to get page via TcpClient?
Related
I have a source html page and I want to do the following:
extracting a specific string from the whole html page and save the new choosing string in a new html page.
creating a database on MySQL with 4 columns.
importing the data from the html page to the table on MySql.
I would be pretty thankful and grateful if someone could help me in that cause I have no that perfect knowledge of using C#.
You could use this code :
HttpClient http = new HttpClient();
//I have put Ebay.com. you could use any.
var response = await http.GetByteArrayAsync("ebay.com");
String source = Encoding.GetEncoding("utf-8").GetString(response, 0, response.Length - 1);
source = WebUtility.HtmlDecode(source);
HtmlDocument Nodes = new HtmlDocument();
Nodes.LoadHtml(source);
In the Nodes object, you will have all the DOM elements in the HTML page.
You could use linq to filter out whatever you need.
Example :
List<HtmlNode> RequiredNodes = Nodes.DocumentNode.Descendants()
.Where(x => x.Attributes["Class"].Contains("List-Item")).ToList();
You will probably need to install Html Agility Pack NuGet or download it from the link.
hope this helps.
I am trying to access these nodes
on this website.
http://bcres.paragonrels.com/publink/default.aspx?GUID=2033c143-cdf1-46b4-9aac-2e27371de22d&Report=Yes
however they appear to be in a secondary Html document within the initial one.
I am confused how I access the secondary html path and then parse through for the
this is an example of one of the nodes.
<div style="top:219px;left:555px;width:45px;height:14px;" id="" class="mls29">2</div>
I am using htmlAgility pack and I recieve null whenever I try to access Div.
I tried working my way down the nodes but It didn't work.
Any help or a place to look up the necessary information to figure this out would be appreciated
var webGet = new HtmlWeb();
var document = webGet.Load("http://bcres.paragonrels.com/publink/default.aspx?GUID=d27a1d95- 623d-4f6a-9e49-e2e46ede136c&Report=Yes");
var divTags = document.DocumentNode.SelectNodes("/html");
var text = document.DocumentNode.InnerText;
MessageBox.Show(text);
You will be able to scrape the data if you access the following url:
http://bcres.paragonrels.com/publink/Report.aspx?outputtype=HTML&GUID=2033c143-cdf1-46b4-9aac-2e27371de22d&ListingID=262103824:0&Report=Yes&view=29&layout_id=63
HtmlWeb w = new HtmlWeb();
var hd = w.Load("http://bcres.paragonrels.com/publink/Report.aspx?outputtype=HTML&GUID=2033c143-cdf1-46b4-9aac-2e27371de22d&ListingID=262103824:0&Report=Yes&view=29&layout_id=63");
var presentedBy = hd.DocumentNode.CssSelect(".mls23.at-phone-link");
if (presentedBy != null)
{
Console.WriteLine(presentedBy.FirstOrDefault().InnerText);
}
As an example, scraping the Presented By field:
Remarks:
I use ScrapySharp nuget package along with HtmlAgilityPack, so I can scrape using css selectors instead of xpath expressions - something I find easier to do.
The url you are scraping from is your problem. I am scraping from the last get request that is performed after the page is loaded, as you can see in the screenshot below, using Firefox developer tools to analyze the site traffic/network requests/responses:
I could not yet identify who/what triggers this http request in the end (may be by javascript code, may be via one of the frame htmls that are requested in the main document (the frame-enabled one).
If you only have a couple of urls like this to scrape, then even manually extracting the correct url will be an option.
We need to export the entire page of MVC Application to PDF for that purpose need to get all the HTML contents (i.e. including dynamic content too)
To get the contents of page we used following code
string contents = File.ReadAllText(path);
but it will give only static content of page(i.e. it gives page source code) not new nodes added in DOM.
Then tried following code but this also gives static content
// WebClient object
WebClient client = new WebClient();
// Retrieve resource as a stream
Stream data = client.OpenRead(new Uri("xxxx.html"));
// Retrieve the text
StreamReader reader = new StreamReader(data);
string htmlContent = reader.ReadToEnd();
So i want to get enitre outerHTML of document in C# with out using any third party DLL . i googled so many links and everyone updated like use webbrowser control and get the content.
i don't how this will be useful for our application. Our Application is MVC4. we need to export the enitre page to PDF so we need enitre content OF HTML (dynamic content too)
How can i use this below code in ourt MVC Application to get document outerHTML
mshtml.HTMLDocument doc = webBrowser1.Document.DomDocument as mshtml.HTMLDocument;
string html = doc.documentElement.outerHTML;
or
var documentAsIHtmlDocument3 = (mshtml.IHTMLDocument3)webBrowser.Document.DomDocument;
StringReader sr = new StringReader(documentAsIHtmlDocument3.documentElement.outerHTML);
htmlDoc.Load(sr)
Any help on this.
You haven't mentioned what the PDF is intended for. Most likely it is for the visitor of the page to download. If that is true, maybe you could use jsPDF. That way you get around the problem with not having access to the entire page serverside.
I've been using this site for a long time to find answers to my questions, but I wasn't able to find the answer on this one.
I am working with a small group on a class project. We're to build a small "game trading" website that allows people to register, put in a game they have they want to trade, and accept trades from others or request a trade.
We have the site functioning long ahead of schedule so we're trying to add more to the site. One thing I want to do myself is to link the games that are put in to Metacritic.
Here's what I need to do. I need to (using asp and c# in visual studio 2012) get the correct game page on metacritic, pull its data, parse it for specific parts, and then display the data on our page.
Essentially when you choose a game you want to trade for we want a small div to display with the game's information and rating. I'm wanting to do it this way to learn more and get something out of this project I didn't have to start with.
I was wondering if anyone could tell me where to start. I don't know how to pull data from a page. I'm still trying to figure out if I need to try and write something to automatically search for the game's title and find the page that way or if I can find some way to go straight to the game's page. And once I've gotten the data, I don't know how to pull the specific information I need from it.
One of the things that doesn't make this easy is that I'm learning c++ along with c# and asp so I keep getting my wires crossed. If someone could point me in the right direction it would be a big help. Thanks
This small example uses HtmlAgilityPack, and using XPath selectors to get to the desired elements.
protected void Page_Load(object sender, EventArgs e)
{
string url = "http://www.metacritic.com/game/pc/halo-spartan-assault";
var web = new HtmlAgilityPack.HtmlWeb();
HtmlDocument doc = web.Load(url);
string metascore = doc.DocumentNode.SelectNodes("//*[#id=\"main\"]/div[3]/div/div[2]/div[1]/div[1]/div/div/div[2]/a/span[1]")[0].InnerText;
string userscore = doc.DocumentNode.SelectNodes("//*[#id=\"main\"]/div[3]/div/div[2]/div[1]/div[2]/div[1]/div/div[2]/a/span[1]")[0].InnerText;
string summary = doc.DocumentNode.SelectNodes("//*[#id=\"main\"]/div[3]/div/div[2]/div[2]/div[1]/ul/li/span[2]/span/span[1]")[0].InnerText;
}
An easy way to obtain the XPath for a given element is by using your web browser (I use Chrome) Developer Tools:
Open the Developer Tools (F12 or Ctrl + Shift + C on Windows or Command + Shift + C for Mac).
Select the element in the page that you want the XPath for.
Right click the element in the "Elements" tab.
Click on "Copy as XPath".
You can paste it exactly like that in c# (as shown in my code), but make sure to escape the quotes.
You have to make sure you use some error handling techniques because Web scraping can cause errors if they change the HTML formatting of the page.
Edit
Per #knocte's suggestion, here is the link to the Nuget package for HTMLAgilityPack:
https://www.nuget.org/packages/HtmlAgilityPack/
I looked and Metacritic.com doesn't have an API.
You can use an HttpWebRequest to get the contents of a website as a string.
using System.Net;
using System.IO;
using System.Windows.Forms;
string result = null;
string url = "http://www.stackoverflow.com";
WebResponse response = null;
StreamReader reader = null;
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
response = request.GetResponse();
reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
result = reader.ReadToEnd();
}
catch (Exception ex)
{
// handle error
MessageBox.Show(ex.Message);
}
finally
{
if (reader != null)
reader.Close();
if (response != null)
response.Close();
}
Then you can parse the string for the data that you want by taking advantage of Metacritic's use of meta tags. Here's the information they have available in meta tags:
og:title
og:type
og:url
og:image
og:site_name
og:description
The format of each tag is: meta name="og:title" content="In a World..."
I recommend Dcsoup. There's a nuget package for it and it uses CSS selectors so it is familiar if you use jquery. I've tried others but it is the best and easiest to use that I've found. There's not much documentation, but it's open source and a port of the java jsoup library that has good documentation. (Documentation for the .NET API here.) I absolutely love it.
var timeoutInMilliseconds = 5000;
var uri = new Uri("http://www.metacritic.com/game/pc/fallout-4");
var doc = Supremes.Dcsoup.Parse(uri, timeoutInMilliseconds);
// <span itemprop="ratingValue">86</span>
var ratingSpan = doc.Select("span[itemprop=ratingValue]");
int ratingValue = int.Parse(ratingSpan.Text);
// selectors match both critic and user scores
var scoreDiv = doc.Select("div.score_summary");
var scoreAnchor = scoreDiv.Select("a.metascore_anchor");
int criticRating = int.Parse(scoreAnchor[0].Text);
float userRating = float.Parse(scoreAnchor[1].Text);
I'd recomend you WebsiteParser - it's based on HtmlAgilityPack (mentioned by Hanlet Escaño) but it makes web scraping easier with attributes and css selectors:
class PersonModel
{
[Selector("#BirdthDate")]
[Converter(typeof(DateTimeConverter))]
public DateTime BirdthDate { get; set; }
}
// ...
PersonModel person = WebContentParser.Parse<PersonModel>(html);
Nuget link
I want to set up a webpage with one small simple string on it. No images, no CSS, not anything else. Just a plain string that is not very long (maximum 20 char).
What is the best way to fetch this string with a C# Form application to use it for a variety of different purposes in the program, like showing people what the newest version of the software is when they boot it up.
I'd use System.Net.WebClient myself like this:
using (var client = new WebClient())
{
string result = client.DownloadString("http://www.test.com");
// TODO: do something with the downloaded result from the remote
}
Try using System.Net.WebClient:
string remoteUri = "http://www.myserver.com/mypage.aspx";
WebClient myWebClient = new WebClient();
string version = myWebClient.DownloadString(remoteUri);