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我在 ASP.NET 中做了第一步，但我遇到了类问题。我想创建一个新的自定义类来支持会话并收集有关我网站上用户数量的信息。我在文件 MySession.cs 中创建了一个类，该类已被 WebMatrix 放入名为“App_data”的目录中。当我尝试在 .cshtml 文件中使用此类时，它会向我抛出找不到该类的信息。我在网上发现，这个类应该放在App_Code中，所以我做了。但是，此时它向我显示了一个错误，即找不到“请求”之类的类。

如何在 WebMatrix 中使用自定义类？

我的 .cshtml 文件中的 c# 代码如下所示：

@{  
  MySession session = new MySession(60);
  session.start();
  var db = Database.Open("studia");
  var data = db.Query("SELECT COUNT(*) as total FROM sessions");
}

和类文件看起来像：

using System;
using System.Collections.Generic;
using System.Web;
using System.Security.Cryptography;
using System.Data;
using System.Data.SqlClient;

    /// <summary>
    /// Summary description for sesss
    /// </summary>
    public class MySession
    {
        private String _session_id;
        private int _session_time;

        public MySession(int session_time = 60)
        {
            _session_time = session_time;
            using (MD5 md5Hash = MD5.Create())
            {
                _session_id = (Request.Cookies["session_id"] != null) ? Server.HtmlEncode(Request.Cookies["sesion_id"].Value) : GetMd5Hash(md5Hash, DateTime.Now);
            }
            cleanup();
        }

        public bool isLogged()
        {
            if (Request.Cookies["session_id"] != null)
            {
                return true;
            }
            return false;
        }

        public void start(string username)
        {
            DateTime now = DateTime.Now;

            var db = Database.Open("studia");

            if (isLogged())
            {
                db.Query("UPDATE sessions SET start_time = " + now + " WHERE session_id = " + _session_id);
            }
            else
            {
                db.Query("INSERT INTO sessions (id, start_time, username) VALUES ('" + _session_id + "', '" + now + "', '" + username + "'");
            }

            HttpCookie session_cookie = new HttpCookie("session_id");
            session_cookie.Value = DateTime.Now;
            session_cookie.Expires = DateTime.Now.AddSeconds(_session_time);
            Response.Cookies.Add(aCookie);
        }

        public void cleanup()
        {
            var db = Database.Open("studia");
            db.Query("DELETE FROM sessions WHERE start_time < " + (DateTime.Now - _session_time));
        }

        static string GetMd5Hash(MD5 md5Hash, string input)
        {

            // Convert the input string to a byte array and compute the hash.
            byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));

            // Create a new Stringbuilder to collect the bytes
            // and create a string.
            StringBuilder sBuilder = new StringBuilder();

            // Loop through each byte of the hashed data
            // and format each one as a hexadecimal string.
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }

            // Return the hexadecimal string.
            return sBuilder.ToString();
        }

        // Verify a hash against a string.
        static bool VerifyMd5Hash(MD5 md5Hash, string input, string hash)
        {
            // Hash the input.
            string hashOfInput = GetMd5Hash(md5Hash, input);

            // Create a StringComparer an compare the hashes.
            StringComparer comparer = StringComparer.OrdinalIgnoreCase;

            if (0 == comparer.Compare(hashOfInput, hash))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

    }
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1 回答 1

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如果要在类中引用 Request 对象（而不是从页面文件中），则需要使用HttpContext.Current例如

public bool isLogged()
{
  return HttpContext.Current.Request.Cookies["session_id"] != null;
}
于 2012-10-13T09:07:11.820 回答