基于Forms窗体验证

==================webconfig==============

   <authentication mode="Forms">
      <forms loginUrl="login.aspx" />
    </authentication>
    <authorization>
      <deny users="?"/>
    </authorization>

===================CS======================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Security;
using System.Data.SqlClient;

public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string username = TextBox1.Text;
        string pwd = TextBox2.Text;
        bool yz = AuthenticateUser(username, pwd);
        if (yz)
        {
            FormsAuthentication.RedirectFromLoginPage(username, false);

        }
        else
        {
            Response.Write("不存在用户");
        }

    }
    private bool AuthenticateUser(string username,string pwd)
    {
        string connstring = System.Configuration.ConfigurationManager.ConnectionStrings["SampleDBConnectionString"].ConnectionString;
        int n = 0;
        using (SqlConnection conn = new SqlConnection(connstring))
        {
            SqlCommand cmd = new SqlCommand("select count(*) from users where username =@username and company =@age", conn);
            cmd.Parameters.Add("@username",System.Data.SqlDbType.NVarChar,10).Value = username;
              cmd.Parameters.Add("@age",System.Data.SqlDbType.NVarChar,20).Value = pwd;
              conn.Open();
              SqlDataReader rs = cmd.ExecuteReader();
              while (rs.Read())
              {
                  n = Convert.ToInt16 (rs.GetValue(0));

              }
            conn.Close();

        }

return (n>0);

    }
}