в 15:30, 26 мая 2010

2010-05-26T15:30:57Z

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2010-05-26T11:56:20Z

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== asynchronous page downloading==



<source lang="csharp">
<%@ Page Async="true" Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="Default" Trace="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Async pages</title>
</head>
<body>
<form id="form1" runat="server">
<div id="pageContent">

<% = rssData %>

</div>
</form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Threading;
using System.Xml;
using System.Net;
using System.IO;
using System.Text;
using System.Xml.XPath;

public partial class Default : System.Web.UI.Page
{
const string RSSFEED = "http://weblogs.asp.net/despos/rss.aspx";
private WebRequest req;
public string rssData;
protected void Page_Load(object sender, EventArgs e)
{
AddOnPreRenderCompleteAsync(
new BeginEventHandler(BeginTask),
new EndEventHandler(EndTask));
}
IAsyncResult BeginTask(object sender, EventArgs e, AsyncCallback cb, object state)
{
Trace.Warn("Begin async: Thread=" +
Thread.CurrentThread.ManagedThreadId.ToString());
req = WebRequest.Create(RSSFEED);
return req.BeginGetResponse(cb, state);
}
void EndTask(IAsyncResult ar)
{
string text;
using (WebResponse response = req.EndGetResponse(ar))
{
StreamReader reader;
using (reader = new StreamReader(response.GetResponseStream()))
{
text = reader.ReadToEnd();
}
rssData = ProcessFeed(text);
}
Trace.Warn("End async: Thread=" +
Thread.CurrentThread.ManagedThreadId.ToString());

}
string ProcessFeed(string feed)
{
StringBuilder sb = new StringBuilder();
XmlDocument doc = new XmlDocument();
doc.LoadXml(feed);
XPathNavigator nav = doc.CreateNavigator();
XPathNodeIterator iterator;
iterator = nav.Select("/rss/channel/title");
iterator.MoveNext();
sb.AppendFormat("<h3>{0}</h3>", iterator.Current.Value);
iterator = nav.Select("/rss/channel/description");
iterator.MoveNext();
sb.AppendFormat("<i>{0}</i>", iterator.Current.Value);
XmlNodeList items = doc.SelectNodes("/rss/channel/item");
sb.Append("<ul>");
foreach (XmlNode n in items)
{
XmlNode title = n.SelectSingleNode("title");
XmlNode link = n.SelectSingleNode("link");
XmlNode date = n.SelectSingleNode("pubDate");
sb.AppendFormat("<li><a href=\"{0}\">{1}</a> on {2}</li>", link.InnerText, title.InnerText, date.InnerText);
}
sb.Append("</ul>");
return sb.ToString();
}
}</source>

== Read page header==



<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="ScrapeHeadings" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Scraping Headings</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Panel ID="panUrl" runat="server" GroupingText="Search" CssClass="myPanel">
Enter Url:
<asp:TextBox ID="txtUrl" runat="server" Columns="50"></asp:TextBox><br />
<asp:Button ID="btnSearch" runat="server" OnClick="btnSearch_Click" Text="Search" />
</asp:Panel>

<asp:Panel ID="panHeadings"
runat="server"
GroupingText="Headings in this Url"
CssClass="myPanel" >
<asp:Literal ID="litContent" runat="server" />
</asp:Panel>
</form>
</body>
</html>

File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
public partial class ScrapeHeadings : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
litContent.Text = "";
}
protected void btnSearch_Click(object sender, EventArgs e)
{
try
{
WebClient client = new WebClient();
string content = client.DownloadString(txtUrl.Text);
Regex reg = new Regex(@"<h\d>.+</h\d>", RegexOptions.IgnoreCase);
MatchCollection mc = reg.Matches(content);
foreach (Match m in mc)
{
litContent.Text += HttpUtility.HtmlEncode(m.Value) + "<br/>";
}
}
catch
{
litContent.Text = "Could not connect to " + txtUrl.Text;
}
}
}</source>

== Retrieve web page==



<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="GetBookImage" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>

</div>
</form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text.RegularExpressions;
using System.Net;
using System.IO;
public partial class GetBookImage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
FindBook findBook = new FindBook();
Response.Redirect(findBook.GetImageUrl(Request.QueryString["isbn"]));
}
}
public class FindBook
{
public string GetImageUrl(string isbn)
{
try
{
isbn = isbn.Replace("-", "");
string bookUrl = "http://www.amazon.ru/exec/obidos/ASIN/" + isbn;
string bookHtml = GetWebPageAsString(bookUrl);
string imgTagPattern = "<img src=\"(http://images.amazon.ru/images/P/" + isbn + "[^\"]+)\"";
Match imgTagMatch = Regex.Match(bookHtml, imgTagPattern);
return imgTagMatch.Groups[1].Value;
}
catch
{
return "";
}
}
public string GetWebPageAsString(string url)
{
WebRequest requestHtml = WebRequest.Create(url);
WebResponse responseHtml = requestHtml.GetResponse();
StreamReader r = new StreamReader(responseHtml.GetResponseStream());
string htmlContent = r.ReadToEnd();
r.Close();
return htmlContent;
}
}</source>

== Trigger Batch Compile==



<source lang="csharp">
using System;
using System.Net;
using System.IO;
using System.Text;
class TriggerBatchCompile {
private static string[] urls = {
"http://localhost/page.aspx",
"http://localhost/anotherApplication/page.aspx",
"http://localhost/yetAnotherApplication/page.aspx"
};
public static void Main(string[] args) {
WebResponse result = null;
for(int i = 0; i < urls.Length; i++) {
try {
Console.WriteLine(urls[i]);
WebRequest request = WebRequest.Create(urls[i]);
result = request.GetResponse();
Stream receiveStream = result.GetResponseStream();
StreamReader streamReader = new StreamReader(receiveStream);
char[] read = new Char[256];
int count = streamReader.Read( read, 0, 256 );
while (count > 0) {
count = streamReader.Read(read, 0, 256);
}
}
catch(Exception e) {
Console.WriteLine(e);
}
finally {
if ( result != null ) {
result.Close();
}
}
}
}
}</source>

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в 15:30, 26 мая 2010

Admin: 1 версия