如何修改以下代码以从数据库拉取数据

我使用以下 asp.net mvc 过滤器来过滤 ips。目前，可以直接在代码中或在配置文件中指定 ip。 如何修改它以从数据库中提取拒绝或允许的 ips 并在过滤器中使用它？ 这是代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Security.Principal;
using System.Configuration;
namespace Miscellaneous.Attributes.Controller
{
/// <summary>
/// Filter by IP address
/// </summary>
public class FilterIPAttribute : AuthorizeAttribute
{
    #region Allowed
    /// <summary>
    /// Comma seperated string of allowable IPs. Example "10.2.5.41,192.168.0.22"
    /// </summary>
    /// <value></value>
    public string AllowedSingleIPs { get; set; }
    /// <summary>
    /// Comma seperated string of allowable IPs with masks. Example "10.2.0.0;255.255.0.0,10.3.0.0;255.255.0.0"
    /// </summary>
    /// <value>The masked I ps.</value>
    public string AllowedMaskedIPs { get; set; }
    /// <summary>
    /// Gets or sets the configuration key for allowed single IPs
    /// </summary>
    /// <value>The configuration key single I ps.</value>
    public string ConfigurationKeyAllowedSingleIPs { get; set; }
    /// <summary>
    /// Gets or sets the configuration key allowed mmasked IPs
    /// </summary>
    /// <value>The configuration key masked I ps.</value>
    public string ConfigurationKeyAllowedMaskedIPs { get; set; }
    /// <summary>
    /// List of allowed IPs
    /// </summary>
    IPList allowedIPListToCheck = new IPList();
    #endregion
    #region Denied
    /// <summary>
    /// Comma seperated string of denied IPs. Example "10.2.5.41,192.168.0.22"
    /// </summary>
    /// <value></value>
    public string DeniedSingleIPs { get; set; }
    /// <summary>
    /// Comma seperated string of denied IPs with masks. Example "10.2.0.0;255.255.0.0,10.3.0.0;255.255.0.0"
    /// </summary>
    /// <value>The masked I ps.</value>
    public string DeniedMaskedIPs { get; set; }

    /// <summary>
    /// Gets or sets the configuration key for denied single IPs
    /// </summary>
    /// <value>The configuration key single I ps.</value>
    public string ConfigurationKeyDeniedSingleIPs { get; set; }
    /// <summary>
    /// Gets or sets the configuration key for denied masked IPs
    /// </summary>
    /// <value>The configuration key masked I ps.</value>
    public string ConfigurationKeyDeniedMaskedIPs { get; set; }
    /// <summary>
    /// List of denied IPs
    /// </summary>
    IPList deniedIPListToCheck = new IPList();
    #endregion

    /// <summary>
    /// Determines whether access to the core framework is authorized.
    /// </summary>
    /// <param name="httpContext">The HTTP context, which encapsulates all HTTP-specific information about an individual HTTP request.</param>
    /// <returns>
    /// true if access is authorized; otherwise, false.
    /// </returns>
    /// <exception cref="T:System.ArgumentNullException">The <paramref name="httpContext"/> parameter is null.</exception>
    protected override bool AuthorizeCore(HttpContextBase httpContext)
    {
        if (httpContext == null)
            throw new ArgumentNullException("httpContext");
        string userIpAddress = httpContext.Request.UserHostAddress;
        try
        {
            // Check that the IP is allowed to access
            bool ipAllowed = CheckAllowedIPs(userIpAddress);
            // Check that the IP is not denied to access
            bool ipDenied = CheckDeniedIPs(userIpAddress);    
            // Only allowed if allowed and not denied
            bool finallyAllowed = ipAllowed && !ipDenied;
            return finallyAllowed;
        }
        catch (Exception e)
        {
            // Log the exception, probably something wrong with the configuration
        }
        return true; // if there was an exception, then we return true
    }
    /// <summary>
    /// Checks the allowed IPs.
    /// </summary>
    /// <param name="userIpAddress">The user ip address.</param>
    /// <returns></returns>
    private bool CheckAllowedIPs(string userIpAddress)
    {
        // Populate the IPList with the Single IPs
        if (!string.IsNullOrEmpty(AllowedSingleIPs))
        {
            SplitAndAddSingleIPs(AllowedSingleIPs, allowedIPListToCheck);
        }
        // Populate the IPList with the Masked IPs
        if (!string.IsNullOrEmpty(AllowedMaskedIPs))
        {
            SplitAndAddMaskedIPs(AllowedMaskedIPs, allowedIPListToCheck);
        }
        // Check if there are more settings from the configuration (Web.config)
        if (!string.IsNullOrEmpty(ConfigurationKeyAllowedSingleIPs))
        {
            string configurationAllowedAdminSingleIPs = ConfigurationManager.AppSettings[ConfigurationKeyAllowedSingleIPs];
            if (!string.IsNullOrEmpty(configurationAllowedAdminSingleIPs))
            {
                SplitAndAddSingleIPs(configurationAllowedAdminSingleIPs, allowedIPListToCheck);
            }
        }
        if (!string.IsNullOrEmpty(ConfigurationKeyAllowedMaskedIPs))
        {
            string configurationAllowedAdminMaskedIPs = ConfigurationManager.AppSettings[ConfigurationKeyAllowedMaskedIPs];
            if (!string.IsNullOrEmpty(configurationAllowedAdminMaskedIPs))
            {
                SplitAndAddMaskedIPs(configurationAllowedAdminMaskedIPs, allowedIPListToCheck);
            }
        }
        return allowedIPListToCheck.CheckNumber(userIpAddress);
    }
    /// <summary>
    /// Checks the denied IPs.
    /// </summary>
    /// <param name="userIpAddress">The user ip address.</param>
    /// <returns></returns>
    private bool CheckDeniedIPs(string userIpAddress)
    {
        // Populate the IPList with the Single IPs
        if (!string.IsNullOrEmpty(DeniedSingleIPs))
        {
            SplitAndAddSingleIPs(DeniedSingleIPs, deniedIPListToCheck);
        }
        // Populate the IPList with the Masked IPs
        if (!string.IsNullOrEmpty(DeniedMaskedIPs))
        {
            SplitAndAddMaskedIPs(DeniedMaskedIPs, deniedIPListToCheck);
        }
        // Check if there are more settings from the configuration (Web.config)
        if (!string.IsNullOrEmpty(ConfigurationKeyDeniedSingleIPs))
        {
            string configurationDeniedAdminSingleIPs = ConfigurationManager.AppSettings[ConfigurationKeyDeniedSingleIPs];
            if (!string.IsNullOrEmpty(configurationDeniedAdminSingleIPs))
            {
                SplitAndAddSingleIPs(configurationDeniedAdminSingleIPs, deniedIPListToCheck);
            }
        }
        if (!string.IsNullOrEmpty(ConfigurationKeyDeniedMaskedIPs))
        {
            string configurationDeniedAdminMaskedIPs = ConfigurationManager.AppSettings[ConfigurationKeyDeniedMaskedIPs];
            if (!string.IsNullOrEmpty(configurationDeniedAdminMaskedIPs))
            {
                SplitAndAddMaskedIPs(configurationDeniedAdminMaskedIPs, deniedIPListToCheck);
            }
        }
        return deniedIPListToCheck.CheckNumber(userIpAddress);
    }
    /// <summary>
    /// Splits the incoming ip string of the format "IP,IP" example "10.2.0.0,10.3.0.0" and adds the result to the IPList
    /// </summary>
    /// <param name="ips">The ips.</param>
    /// <param name="list">The list.</param>
    private void SplitAndAddSingleIPs(string ips,IPList list)
    {
        var splitSingleIPs = ips.Split(',');
        foreach (string ip in splitSingleIPs)
            list.Add(ip);
    }
    /// <summary>
    /// Splits the incoming ip string of the format "IP;MASK,IP;MASK" example "10.2.0.0;255.255.0.0,10.3.0.0;255.255.0.0" and adds the result to the IPList
    /// </summary>
    /// <param name="ips">The ips.</param>
    /// <param name="list">The list.</param>
    private void SplitAndAddMaskedIPs(string ips, IPList list)
    {
        var splitMaskedIPs = ips.Split(',');
        foreach (string maskedIp in splitMaskedIPs)
        {
            var ipAndMask = maskedIp.Split(';');
            list.Add(ipAndMask[0], ipAndMask[1]); // IP;MASK
        }
    }
    public override void OnAuthorization(AuthorizationContext filterContext)
    {
        base.OnAuthorization(filterContext);
    }
}
}

用法示例：

1. 直接在代码中指定 IP

    [FilterIP(
       AllowedSingleIPs="10.2.5.55,192.168.2.2",
       AllowedMaskedIPs="10.2.0.0;255.255.0.0,192.168.2.0;255.255.255.0"
   

   ）]

   public class HomeController 
   {
   // Some code here
   }
   

2. 或者，从 Web.config 加载配置

    [FilterIP(
       ConfigurationKeyAllowedSingleIPs="AllowedAdminSingleIPs",
       ConfigurationKeyAllowedMaskedIPs="AllowedAdminMaskedIPs",
       ConfigurationKeyDeniedSingleIPs="DeniedAdminSingleIPs",
       ConfigurationKeyDeniedMaskedIPs="DeniedAdminMaskedIPs"
   

   ）]

   <configuration>
   <appSettings>
   <add key="AllowedAdminSingleIPs" value="localhost,127.0.0.1"/> <!-- Example "10.2.80.21,192.168.2.2" -->
   <add key="AllowedAdminMaskedIPs" value="10.2.0.0;255.255.0.0"/> <!-- Example "10.2.0.0;255.255.0.0,192.168.2.0;255.255.255.0" -->
   <add key="DeniedAdminSingleIPs" value=""/>    <!-- Example "10.2.80.21,192.168.2.2" -->
   <add key="DeniedAdminMaskedIPs" value=""/>    <!-- Example "10.2.0.0;255.255.0.0,192.168.2.0;255.255.255.0" -->
   </appSettings>
   </configuration>
   

[FilterIP(AllowedAdminSingleIPs =true,DeniedAdminSingleIPs=false)]