Net学习日记_ADO.Net_2_练习（登录逻辑）

using System;using System.Data.SqlClient;using System.Windows.Forms;namespace Test01{ ???public partial class Form1 : Form ???{ ???????public Form1() ???????{ ???????????InitializeComponent(); ???????} ???????private void BtOK_Click(object sender, EventArgs e) ???????{ ???????????SqlConnection conn = new SqlConnection("server=PC201609230944\\SQL2005;database=HeiMaBlog;user=sa;pwd=123456"); ???????????SqlCommand cmd = new SqlCommand("select *,datediff(minute,LastErrTime,GETDATE()) from UserInfo where UserName=@UserName", conn); ???????????cmd.Parameters.Add(new SqlParameter("@UserName", TxName.Text.Trim())); ???????????conn.Open(); ???????????SqlDataReader dr = cmd.ExecuteReader(); ???????????if (dr.HasRows) ???????????{ ???????????????dr.Read();////不管dr取到多少条数据，只取出前面第一行(调用一次read，就会读取一行，也只读取一行) ???????????????if (dr.GetInt32(5) < 15) ???????????????{ ???????????????????MessageBox.Show("时间未到，请稍后重试！！"); ???????????????????return; ???????????????} ???????????????if (dr[2].ToString() == TxPwd.Text.Trim()) ???????????????{ ???????????????????MessageBox.Show("登录成功！！"); ???????????????????UserInfo.ReSetErrTimes(dr.GetInt32(0));//登录成功后，就重置错误时间 ???????????????} ???????????????else ???????????????{ ???????????????????//如果密码不正确！！ ???????????????????MessageBox.Show("登录失败，密码错误"); ???????????????????UserInfo.UpDateErrTimes(dr.GetInt32(0)); ???????????????????// 错误三次就更新错误时间 ???????????????????if (dr.GetInt32(3) + 1 == 3) ???????????????????{ ???????????????????????UserInfo.UpDateLastErrTime(dr.GetInt32(0)); ???????????????????????UserInfo.ReSetErrTimes(dr.GetInt32(0)); ???????????????????} ???????????????} ???????????} ???????????else ???????????{ ???????????????MessageBox.Show("该用户不存在！！！"); ???????????} ???????} ???}}

using System.Data.SqlClient;namespace Test01{ ???class UserInfo ???{ ???????/// <summary> ???????/// 更新错误时间！！ ???????/// </summary> ???????/// <param name="id"></param> ???????/// <returns></returns> ???????public static int UpDateErrTimes(int id) ???????{ ???????????using (SqlConnection conn = new SqlConnection("server=PC201609230944\\SQL2005;database=HeiMaBlog;user=sa;pwd=123456")) ???????????{ ???????????????using (SqlCommand cmd = new SqlCommand("update UserInfo set ErrTimes=ErrTimes+1 where id=" + id, conn)) ???????????????{ ???????????????????conn.Open(); ???????????????????return cmd.ExecuteNonQuery(); ???????????????} ???????????} ???????} ???????/// <summary> ???????/// 重置错误时间 ???????/// </summary> ???????/// <param name="id"></param> ???????/// <returns></returns> ???????public static int ReSetErrTimes(int id) ???????{ ???????????using (SqlConnection conn = new SqlConnection("server=PC201609230944\\SQL2005;database=HeiMaBlog;user=sa;pwd=123456")) ???????????{ ???????????????using (SqlCommand cmd = new SqlCommand("update UserInfo set ErrTimes=0 where id=" + id, conn)) ???????????????{ ???????????????????conn.Open(); ???????????????????return cmd.ExecuteNonQuery(); ???????????????} ???????????} ???????} ???????/// <summary> ???????/// 更新3次错误的输入时间 ???????/// </summary> ???????/// <param name="id"></param> ???????/// <returns></returns> ???????public static int UpDateLastErrTime(int id) ???????{ ???????????using (SqlConnection conn = new SqlConnection("server=PC201609230944\\SQL2005;database=HeiMaBlog;user=sa;pwd=123456")) ???????????{ ???????????????using (SqlCommand cmd = new SqlCommand("update UserInfo set LastErrTime = getDate() where id= " + id, conn)) ???????????????{ ???????????????????conn.Open(); ???????????????????return cmd.ExecuteNonQuery(); ???????????????} ???????????} ???????} ???}}