当前上下文不存在tbusername

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

namespace WebApplication5
{
public partial class Defauit : System.Web.UI.Page
{
private readonly string connstr;

    /// <summary>
    /// 用户登录
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void BtnLogin_Click(object sender, EventArgs e)
    {
        if (tbusername.Text=="")
        {
            Response.Write(@"<script>alert('用户名不能为空！');</script>");
        }
        if (tbpsw.Text=="")
        {
            Response.Write(@"<script>alert('密码不能为空！');</script>");
        }
        string username=tbusername.Text;
        string password=tbpsw.Text;
        string sql = "select * from T_user where username=@username and password=@password";
        SqlParameter[] parameter = { new SqlParameter("@username",username),new SqlParameter("@password",password)};
        using (SqlConnection conn = new SqlConnection(connstr))
        {
            conn.Open();
            using (SqlCommand cmd = conn.CreateCommand())
            {
                cmd.CommandText = sql;
                cmd.Parameters.AddRange(parameter);
                DataSet ds = new DataSet();
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                adapter.Fill(ds);
                DataTable table = ds.Tables[0];
                if(table != null)
                    Response.Write(@"<script>alert('登录成功！');</script>");
                else
                    Response.Write(@"<script>alert('登录失败！');</script>");
            }
        }
    }
    /// <summary>
    /// 用户注册
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void BrnRegister_Click(object sender, EventArgs e)
    {
        string username = tbusername.Text;
        string password = tbpsw.Text;
        string sql = "Insert into T_user(username, password) values(@username,@password)";
        SqlParameter[] parameters = { new SqlParameter("@username", username), new SqlParameter("@password", password) };
        using (SqlConnection conn = new SqlConnection(connstr))
        {
            conn.Open();
            using (SqlCommand cmd = conn.CreateCommand())
            {
                cmd.CommandText = sql;
                cmd.Parameters.AddRange(parameters);
                cmd.ExecuteNonQuery();
            }
        }

        Response.Write(@"<script>alert('注册成功！');</script>");
    }
}

}

里面的tbusername和tbpsw一直存在当前上下文不存在的问题！！！！

把aspx的Inherits改成“命名空间.类名”

https://zhidao.baidu.com/question/309128746224564284.html
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