singlepage.cs

用C#编写的一个款搜索engine的源代码！摘自<Visual c#2005 程序设计>

using System;
using System.Text;
using System.IO;
using System.Collections;
using System.Net;

namespace SinglePage
{
	/// <summary>
	/// Summary description for SinglePage.
	/// </summary>
	public class SinglePage
	{

		/// <summary>
		/// Download HTML code of given URL.
		/// </summary>
		/// <param name="URL">URL</param>
		/// <param name="HTML">HTML code</param>
		/// <returns>true if successfully download, false if Unable to process request at this time.</returns>
		public static bool Download(string URL, ref string HTML) 
		{   
			Stream strmPage = null;
			StreamReader srPage = null;
			try
			{
				HttpWebRequest wrqPage = (HttpWebRequest)WebRequest.Create(URL);
				wrqPage.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)";
				WebResponse wrpPage = wrqPage.GetResponse();
				strmPage = wrpPage.GetResponseStream();
				srPage = new StreamReader(strmPage);
				HTML = srPage.ReadToEnd();
				strmPage.Close();
				return true;
			}
			catch (Exception ex)
			{
				SinglePage.LogAppend("Download ["+URL+"] Error:\n"+ex.Message);
				if (strmPage != null)
				{
					strmPage.Close();
				}
				return false;
			}
		}

		/// <summary>
		/// Append some content [log] to the log file. 
		/// If the file is not exist, it will be created automatically by this function.
		/// </summary>
		/// <param name="log">Content string to be appended.</param>
		public static void LogAppend(String log)
		{
			FileInfo file = new FileInfo("log.ini");
			if(!file.Exists)
			{
				FileStream fs = file.Create();
				fs.Close();
			}
			
			StreamWriter w = new StreamWriter(file.FullName,true);
			w.WriteLine(log);
			w.Close();
		}

	}
}