name = 'alex'   #正確的用戶名
passwd = '123456'  #正確的密碼
lock_usr = []   #鎖定賬號列表

for i in range(0,3):
 usr_name = input("用戶名：")
 usr_passwd = input("密碼：")
 if usr_name == name and usr_passwd == passwd:
  print("玩命加載中...")
  break
 elif name != usr_name or passwd != usr_passwd:
  if i < 2:
   print("用戶名密碼錯誤，請重新輸入！")
  else:
   lock_usr.append(usr_name)     #將輸入錯誤三次的的賬號添加到鎖定列表中
   print("對不起！機會只有三次，您的賬號密碼被鎖定")
 elif usr_name in lock_usr:
  print("該賬號已鎖定，請解鎖后登陸")

#region 密碼輸入三次錯誤后鎖定用戶功能
  #region 增加錯誤次數(shù)的方法
  ///<summary>
  ///增加錯誤次數(shù)的方法
  ///</summary>
  private void IncErrorTime()
  {
   string ConnStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
   using (SqlConnection conn = new SqlConnection(ConnStr))
   {
    using (SqlCommand updateCmd = conn.CreateCommand())
    {
     updateCmd.CommandText = "update T_Admin set errortime=errortime+1 whereUsername=@username";
     updateCmd.Parameters.Add(new SqlParameter("username", cmbuserName.Text));
     conn.Open();
     updateCmd.ExecuteNonQuery();
    }
   }
  } 
  #endregion
  #region 錯誤次數(shù)清0
  ///<summary>
  ///錯誤次數(shù)清0
  ///</summary>
  private void NotErrorTime()
  {
   string ConnStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
   using (SqlConnection conn = new SqlConnection(ConnStr))
   {
    using (SqlCommand updateCmd = conn.CreateCommand())
    {
     updateCmd.CommandText = "update T_Admin set errortime=0 whereUsername=@username";
     updateCmd.Parameters.Add(new SqlParameter("username", cmbuserName.Text));
     conn.Open();
     updateCmd.ExecuteNonQuery();
    }
   }
  } 
  #endregion
  #region 密碼錯誤3次,記錄當前時間加30分鐘
  ///<summary>
  ///密碼錯誤3次,記錄當前時間加30分鐘
  ///</summary>
  private void IncLoginTime()
  {
   string ConnStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
   using (SqlConnection conn = new SqlConnection(ConnStr))
   {
    using (SqlCommand updateCmd = conn.CreateCommand())
    {
     updateCmd.CommandText = "update T_Admin set logintime=@logintime whereUsername=@username";
     DateTime logintime = DateTime.Now.AddMinutes(30);
     updateCmd.Parameters.Add(new SqlParameter("username", cmbuserName.Text));
     updateCmd.Parameters.Add(new SqlParameter("logintime", logintime.ToString()));
     conn.Open();
     updateCmd.ExecuteNonQuery();
    }
   }
  } 
  #endregion
  #region 按鈕事件判斷用戶登錄3次失效后鎖定用戶30分鐘
  private void BtnClike()
  {
   string username = cmbuserName.Text;
   string password = txtPwd.Text;
   string ConnStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
   using (SqlConnection conn = new SqlConnection(ConnStr))
   {
    using (SqlCommand cmd = conn.CreateCommand())
    {
     cmd.CommandText = "select * from T_Admin whereusername=@username";
     cmd.Parameters.Add(new SqlParameter("username", username));
     conn.Open();
     using (SqlDataReader reader = cmd.ExecuteReader())
     {
      if (reader.Read())
      {
       //用戶存在
       string dbpassword = reader.GetString(reader.GetOrdinal("password"));
       DateTime logintime = reader.GetDateTime(reader.GetOrdinal("logintime"));
       //判斷當前時間是是服務器允許登錄時間
       if (logintime > DateTime.Now)
       {
        MessageBox.Show("一定時間內(nèi)禁止登錄");
        return;
       }
       //如果密碼正確
       if (dbpassword == txtPwd.Text)
       {
        NotErrorTime();
        MessageBox.Show("登錄成功!");
       }
       //如果密碼錯誤
       else
       {
        int errortime = reader.GetInt32(reader.GetOrdinal("errortime"));
        if (errortime >= 2)
        {
         MessageBox.Show("密碼錯誤次數(shù)太多!");
         IncLoginTime();
         NotErrorTime();
         return;
        }
        MessageBox.Show("密碼錯誤!");
        IncErrorTime();//密碼錯誤,次數(shù)加1
       }
      }
      else//用戶名不存在
      {
       MessageBox.Show("用戶名不存在!");
       return;
      }
     }
    }
   }
  }
  #endregion
  #endregion