dataset  登录

(2010-11-25 08:44:45)

标签： it

分类： 努力学习.net

        private void button6_Click(object sender, EventArgs e)
        {
            DataTable db = SQLHelper.ExecuteReader("select * from T_Users where UserName = @UserName",new SqlParameter("UserName",txtUserName.Text));

            if (db.Rows.Count <= 0)
            {
                MessageBox.Show("用户名不存在！");
                return;
            }
            else
            {
                DataRow row = db.Rows[0];
                int errorTimes = Convert.ToInt32(row["ErrorTimes"]);
                if (errorTimes >= 3)
                {
                    MessageBox.Show("错误次数过多！禁止登录！！！");
                    return;
                }
                string password = Convert.ToString(row["Password"]);
                if (txtPassword.Text == password)
                {
                    SQLHelper.ExecuteNonQuery("update T_Users set ErrorTimes = 0 where UserName = @UserName",new SqlParameter("UserName",txtUserName.Text));
                    MessageBox.Show("登录成功！");
                }
                else
                {
                    SQLHelper.ExecuteNonQuery("update T_Users set ErrorTimes = ErrorTimes + 1 where UserName = @UserName", new SqlParameter("UserName", txtUserName.Text));
                    MessageBox.Show("密码错误！");
                }

            }

        }

 

 

 public static DataTable ExecuteReader(string sql, params SqlParameter[] parameters)
        {
            string connStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = sql;
                    foreach (SqlParameter parameter in parameters)
                    {
                        cmd.Parameters.Add(parameter);
                    }
                    DataSet dataset = new DataSet();
                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    adapter.Fill(dataset);
                    return dataset.Tables[0];
                }
            }
        }