代码

using System;
using System.Collections;
using System.Security.Cryptography;
using System.Text;
using System.Web;
using System.IO;

using System.Collections.Specialized;

using System.Web.Caching;
using System.Xml;
using System.Configuration;
using System.Xml.Serialization;

namespace Utility
{
 /// <summary>
 /// Common 的摘要说明。
 /// </summary>
 public class Common
 {
  #region 成员字段
  public static readonly string CacheKey = "ForumsConfiguration";
  private Hashtable providers = new Hashtable();
  private Hashtable extensions = new Hashtable();
  private static readonly Cache cache = HttpRuntime.Cache;
  private string defaultProvider;
  private string defaultLanguage;
  private string forumFilesPath;
  private bool disableBackgroundThreads = false;
  private bool disableIndexing = false;
  private bool disableEmail = false;
  private string passwordEncodingFormat = "unicode";
  private int threadIntervalEmail = 15;
  private int threadIntervalStats = 15;
  //private SystemType systemType = SystemType.Self;
  private short smtpServerConnectionLimit = -1;
  private bool enableLatestVersionCheck = true;
  private string uploadFilesPath = "/Upload/";
  private XmlDocument XmlDoc = null;
  #endregion
  public Common()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //
  }
  public enum UserPasswordFormat
  {
   ClearText = 0,
   MD5Hash = 1,
   Sha1Hash = 2,
   Encyrpted = 3
  }
  public string PasswordEncodingFormat
  {
   get { return passwordEncodingFormat; }
  }
  public static string Encrypt(UserPasswordFormat format, string cleanString, string salt)
  {
   Byte[] clearBytes;
   Byte[] hashedBytes;
   Encoding encoding = Encoding.GetEncoding("unicode");
   clearBytes = encoding.GetBytes(salt.ToLower().Trim() + cleanString.Trim());

   hashedBytes = ((HashAlgorithm) CryptoConfig.CreateFromName("MD5")).ComputeHash(clearBytes);

     return BitConverter.ToString(hashedBytes);
     ;                     
   
  }
  public static Common GetConfig()
  {
   Common config = cache.Get(CacheKey) as Common;
   if(config == null)
   {
    string path;
    if(HttpContext.Current != null)
     path = HttpContext.Current.Server.MapPath("~/Forums.config");
    else
     path = Directory.GetCurrentDirectory() + Path.DirectorySeparatorChar + "Forums.config";

    XmlDocument doc = new XmlDocument();
    doc.Load(path);
    config = new Common(doc);
    cache.Insert(CacheKey,config,new CacheDependency(path),DateTime.MaxValue,TimeSpan.Zero,CacheItemPriority.AboveNormal,null);

    //cache.ReSetFactor(config.CacheFactor);
   }
   return config;
           
  }
 }
}