aspx 简单登录

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

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

    }

    public bool checklogin(Sysuser user,ref string message)
    {
        
        string sqlconstr = "Data Source=.;Initial Catalog=Example;Integrated Security=true";
        string sql = "select * from SystemUser where SystemUser.uesrid=@userid";
        SqlConnection con = new SqlConnection(sqlconstr);
        SqlCommand cmd = new SqlCommand(sql, con);
        SqlParameter[] para = {
                                  new SqlParameter("@userid",user.Userid),
                                  //new SqlParameter("@userpwd",user.Pwd),
                              };
        con.Open();
        cmd.Parameters.AddRange(para);
        SqlDataReader sdr = cmd.ExecuteReader();
       
        if(sdr.HasRows)
        {
            if(sdr.Read()&&sdr["userpwd"].ToString()==user.Pwd)
            {
                con.Close();
                message = "成功";
                return true;
                
            }
            else
            {
                message = "密码错误！";
                return false;
            }
           
          
        }
        else
        {
            message = "没有此用户";
            return false;
        }
        
    }
    protected void btnlogin_Click1(object sender, EventArgs e)
    {

        //获取用户输入的信息
        Sysuser user = new Sysuser();
        user.Userid = txtuser.Text.Trim();
        user.Pwd = txtpwd.Text.Trim();
        string message = "";
        //登录验证用户的输入
        if (checklogin(user, ref message))
        {
            //成功跳转到主页
            Session["UserInfo"] = user;
        }
        else
        {
            //失败就提示失败信息
            ltl.Text = "登录失败";
        }
    }
}