sharepoint 代码提升匿名用户、只读用户修改列表的权限

自己编写了一个对sharepoint list（UserInfo）操作的页面，添加到sharepoint网站，匿名用户或者对list（UserInfo）只用只读权限的用户想对list(UserInfo)进行操作（添加、删除、修改）就只能提升用户的权限。

/// <summary>
        /// 添加
        /// </summary>
        /// <returns></returns>
        private bool AddItem(string username,string password)
        {
            bool flag = false;
            SPSecurity.RunWithElevatedPrivileges(//提升权限
                delegate()
                {
                    try
                    {
                        using (SPWeb web = new SPSite(webUrl).OpenWeb())
                        {
                            web.AllowUnsafeUpdates = true;
                            SPList list = web.GetList(webUrl + "/Lists/UserInfo");
                            SPListItem item = list.Items.Add();
                            item["Title"] = username;
                            item["Password"] = password;
                            item["Author"] = SPContext.Current.Web.CurrentUser;
                            item.Update();
                            flag = true;
                        }
                    }
                    catch (Exception ex)
                    {
                        flag = false;
                    }
                });
            return flag;
        }

操作完以上代码我们会发现以匿名用户添加的数据他的创建人（item["Author"]）是“系统账户”，登录后的用户的创建人（item["Author"]）是本人。