如何在C#中修改特定路径的IIS授权规则？

using Microsoft.Web.Administration;

public void ModifyIISAuthorizationRule(string siteName, string virtualPath, string userName, string accessType)
{
    using (ServerManager serverManager = new ServerManager())
    {
        Configuration config = serverManager.GetWebConfiguration(siteName);
        ConfigurationSection authorizationSection = config.GetSection("system.webServer/security/authorization", virtualPath);
        ConfigurationElementCollection authorizationRules = authorizationSection.GetCollection("add");

        foreach (ConfigurationElement ruleElement in authorizationRules)
        {
            string rulePath = ruleElement.GetAttributeValue("path").ToString();
            string ruleUsers = ruleElement.GetAttributeValue("users").ToString();

            if (rulePath.Equals(virtualPath, StringComparison.OrdinalIgnoreCase) && ruleUsers.Equals(userName, StringComparison.OrdinalIgnoreCase))
            {
                ruleElement.SetAttributeValue("accessType", accessType);
                serverManager.CommitChanges();
                break;
            }
        }
    }
}