.net实现网站用户登录认证

private void SetAuthCookie(string userId, bool createPersistentCookie)
{　　var ticket = new FormsAuthenticationTicket(2, userId, DateTime.Now, DateTime.Now.AddDays(7), true, "", FormsAuthentication.FormsCookiePath)
　　string ticketEncrypted = FormsAuthentication.Encrypt(ticket)
　　HttpCookie cookie
　　if (createPersistentCookie)//是否在设置的过期时间内一直有效　　
{　　　　cookie = new HttpCookie(FormsAuthentication.FormsCookieName, ticketEncrypted)　　　　
{　　　　　　HttpOnly = true,　　　　　　Path = FormsAuthentication.FormsCookiePath,　　　　　　Secure = FormsAuthentication.RequireSSL,　　　　　　Expires = ticket.Expiration,　　　　　　Domain = "cnblogs.com"//这里设置认证的域名，同域名下包括子域名如aa.cnblogs.com或bb.cnblogs.com都保持相同的登录状态　　　　}
　　}　　else　　
{　　　　cookie = new HttpCookie(FormsAuthentication.FormsCookieName, ticketEncrypted)　　　　
{　　　　　　HttpOnly = true,　　　　　　Path = FormsAuthentication.FormsCookiePath,　　　　　　Secure = FormsAuthentication.RequireSSL,　　　　　　//Expires = ticket.Expiration,//无过期时间的，浏览器关闭后失效　　　　　　Domain = "cnblogs.com"　　　　}
　　}　　HttpContext.Current.Response.Cookies.Remove(FormsAuthentication.FormsCookieName)
　　HttpContext.Current.Response.Cookies.Add(cookie)
}

public bool IsAuthenticated
{　　get　　
{　　　　bool isPass = System.Web.HttpContext.Current.User.Identity.IsAuthenticated
　　　　if (!isPass)　　　　　　SignOut()
　　　　return isPass
　　}}

public string GetCurrentUserId()
{   return _httpContext.User.Identity.Name
}

using System
using System.Data
using System.Configuration
using System.Collections
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.Data.SqlClient
public partial class Login : System.Web.UI.Page
{protected void Page_Load(object sender, EventArgs e)
{}protected void Button1_Click(object sender, EventArgs e)
{ string connString = Convert.ToString(ConfigurationManager.ConnectionStrings["001ConnectionString"])
//001ConnectionString是我在webconfig里配置的数据库连接。SqlConnection conn = new SqlConnection(connString)
 string strsql = "select * from User_table where User_name=&apos
" + UserName.Text + "&apos
 and Password=&apos
" + Password.Text + "&apos
"
SqlCommand cmd = new SqlCommand(strsql, conn)
conn.Open()
SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection)
if (dr.Read())
{ Response.Redirect("index.aspx")
conn.Close()
}else
{FailureText.Text = "登陆失败,请检查登陆信息!"
conn.Close()
Response.Write("")
}}protected void Button2_Click(object sender, EventArgs e) //文本框重置按钮
{UserName.Text = ""
Password.Text = ""
}}

<
%@ Page Language="C
#" AutoEventWireup="true" CodeFile="Login.aspx.cs" Inherits="Login" %>
 
用户登陆
用户名:
密码: