net2.0下的简繁转换

规则：
 以URL地址来决定简繁的显示，zh-cn/index.htm为简体,zh-tw/index.htm为繁体。

思路很简单，以IHttpHandler接口为基类，写一个类，用来处理HttpHandler，用ProcessRequest方法来处理客户端的请求。在ProcessRequest方法中获取url值，有zh-tw就用繁体，反之用简体。

using System;
using System.IO;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
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;
using System.Text.RegularExpressions;
using Microsoft.VisualBasic;

导入以上命名空间，注意Microsoft.VisualBasic，要先引用一下Microsoft.VisualBasic。

public class HtmlHttpHandler : IHttpHandler
{
   //这里是定义的一个结构 ，与简繁转换无关，主要设定url重写的规则。
    private List<RegexInfo> _regex_list = new List<RegexInfo>();

    public HtmlHttpHandler()
    {
        DataSet ds = new DataSet();
        ds.ReadXml(ConfigurationManager.AppSettings["RegexsXml"]);
        foreach (DataRow r in ds.Tables["regex"].Rows)
            _regex_list.Add(new RegexInfo(((string)r["b"]).Trim(), ((string)r["a"]).Trim()));
    }

    //主方法

    public void ProcessRequest(HttpContext context)
    {
        string path = context.Request.Path;
        //foreach (RegexInfo r in _regex_list)
            //path = Regex.Replace(path, r._before, r._after);   //url重写
       //开始判断并转换
        if (path.IndexOf("zh-tw") != -1)
        {
            path = path.Replace("zh-tw", "zh-cn");
             //以自定义方式过滤
            context.Response.Filter = new CnToTwStream(context.Response.Filter, context.Response.ContentEncoding);
        }
        context.Server.Transfer(path);
    }

    // Override the IsReusable property.
    public bool IsReusable
    {
        get { return true; }
    }
}

CnToTwStream类实现简繁的转换

class CnToTwStream : Stream
{
    private Stream _sink;
    private MemoryStream _ms;
    private Encoding _encoding;

    public CnToTwStream(Stream sink, Encoding encoding)
    {
        _sink = sink;
        _ms = new MemoryStream();
        _encoding = encoding;
    }

    public override bool CanRead
    {
        get { return false; }
    }

    public override bool CanSeek
    {
        get { return false; }
    }

    public override bool CanWrite
    {
        get { return true; }
    }

    public override long Length
    {
        get { return _ms.Length; }
    }

    public override long Position
    {
        get { return _ms.Position; }
        set { throw new NotSupportedException(); }
    }

    public override int Read(byte[] buffer, int offset, int count)
    {
        throw new NotSupportedException();
    }

    public override long Seek(long offset, System.IO.SeekOrigin direction)
    {
        throw new NotSupportedException();
    }

    public override void SetLength(long length)
    {
        throw new NotSupportedException();
    }

    public override void Close()
    {
        _ms.Close();
        byte[] buffer_cn = _ms.GetBuffer();
        string str_cn = _encoding.GetString( buffer_cn );
        //用Strings类的StrConv方法,其中TraditionalChinese是VisualBasic中的一个枚举
        string str_tw = Strings.StrConv(str_cn, VbStrConv.TraditionalChinese, 0);
        str_tw = str_tw.Replace("__zh-cn__", "__zh-tw__");
        byte[] buffer_tw = _encoding.GetBytes(str_tw);
        using (_sink)
        {
            _sink.Write(buffer_tw, 0, buffer_tw.Length);
        }
    }

    public override void Flush()
    {
        _ms.Flush();
    }

    public override void Write(byte[] buffer, int offset, int count)
    {
        _ms.Write(buffer, offset, count);
    }
}