asp.Netページ符号化自動認識コード

 
  
using System; 
  
using System.Net; 
  
using System.Text; 
  
using System.Text.RegularExpressions; 
  
 
  
class Program 
  
{ 
  
//      HTML  ，     charset    Encoding 
  
static string GetHtml(string url) 
  
{ 
  
return GetHtml(url, null); 
  
} 
  
 
  
//      HTML  ，  Encoding 
  
static string GetHtml(string url, Encoding encoding) 
  
{ 
  
byte[] buf = new WebClient().DownloadData(url); 
  
if (encoding != null) return encoding.GetString(buf); 
  
string html = Encoding.UTF8.GetString(buf); 
  
encoding = GetEncoding(html); 
  
if (encoding == null || encoding == Encoding.UTF8) return html; 
  
return encoding.GetString(buf); 
  
} 
  
 
  
//      HTML       Encoding 
  
static Encoding GetEncoding(string html) 
  
{ 
  
string pattern = @"(?i)\bcharset=(?[-a-zA-Z_0-9]+)"; 
  
string charset = Regex.Match(html, pattern).Groups["charset"].Value; 
  
try { return Encoding.GetEncoding(charset); } 
  
catch (ArgumentException) { return null; } 
  
} 
  
 
  
//      
  
static void Main() 
  
{ 
  
Console.WriteLine(GetHtml(//www.jb51.net)); 
  
 
  
Console.Read(); 
  
} 
  
}