[英]How do I create a limit of logins on my login screen?
我目前正在尝试用C#设计一个atm机器,对此我还是很陌生。 在尝试登录失败3次后,我希望登录屏幕返回到我的欢迎屏幕,但是我不知道从哪里开始以及如何在我的程序中实现我的代码。
我当前的登录屏幕代码如下:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.Common;
namespace bankkk
{
public partial class FrmLogin : Form
{
public FrmLogin()
{
InitializeComponent();
}
public static OleDbConnection con = new OleDbConnection();
string dbProvider;
string dbSource;
OleDbDataAdapter da;
public static DataSet ds1 = new DataSet();
string sql;
string pin;
int rownum = 0;
bool valid = false;
private void FrmLogin_Load(object sender, EventArgs e)
{
dbProvider = "PROVIDER=Microsoft.ACE.OLEDB.12.0;";
dbSource = "Data Source = 'd:\\bank11.accdb'";
con.ConnectionString = dbProvider + dbSource;
ds1 = new DataSet();
con.Open();
sql = " SELECT tblCustomers.* FROM tblCustomers";
da = new OleDbDataAdapter(sql, con);
rownum = da.Fill(ds1, "tblCustomers");
con.Close();
}
private void btnexit_Click(object sender, EventArgs e)
{
System.Environment.Exit(0);
this.Close();
}
//METHOD VALIDATE
private bool validate()
{
ds1 = new DataSet();
con.Open();
sql = "SELECT tblCustomers.* FROM tblCustomers WHERE ((tblCustomers.AccountNo) = '" + txtAccount.Text + "')";
da = new OleDbDataAdapter(sql, con);
rownum = da.Fill(ds1, "tblCustomers");
con.Close();
if (rownum != 1)
{
MessageBox.Show("Not a valid Account");
return false;
}
else
{
pin = ds1.Tables["tblCustomers"].Rows[0][4].ToString();
if (pin == txtPin.Text)
{
return true;
}
else
{
MessageBox.Show("INVALID PIN");
return false;
}
}
}
private void btnLogin_Click(object sender, EventArgs e)
{
valid = validate();
if (valid == true)
{
if (txtAccount.Text == "11111111" && txtPin.Text == "9999")
{
Frmmanager Manager = new Frmmanager();
this.Close();
Manager.Show();
}
else
{
frmaccount account = new frmaccount();
this.Close();
account.Show();
{
txtAccount.Clear();
txtPin.Clear();
}
}
}
}
private void btnlogin_Click_1(object sender, EventArgs e)
{
valid = validate();
if (valid == true)
{
if (txtAccount.Text == "11111111" && txtPin.Text == "9999")
{
Frmmanager Manager = new Frmmanager();
this.Close();
Manager.Show();
}
else
{
frmaccount account = new frmaccount();
this.Close();
account.Show();
{
txtAccount.Clear();
txtPin.Clear();
}
}
}
}
}
}
您说的是返回到我的欢迎屏幕 ,所以我假设您正在使用.ShowDialog()
而不是.Show()
显示FrmLogin
。 这样,您只需要关闭旧表格即可。
如果您只是在执行.Show()
,则可以执行以下操作:
public partial class FrmWelcome {
//in some part of your code...
var frmLogin = new FrmLogin();
//when the login form is closed, show this one.
//Depending on your application, you might want to add some boolean variable
//to the Login Form that will be true if the user authentication failed, and
//show this form again only if it is true.
frmLogin.Closed += (s, e) => this.Show();
this.Hide();
frmLogin.Show();
}
试试下面的代码。 这个想法是有一个failedAttempts
变量,每次验证代码失败时该变量都会增加。 当它等于3时,您只需关闭窗体(请参见上文)。
namespace bankkk
{
public partial class FrmLogin : Form
{
public FrmLogin()
{
InitializeComponent();
}
...
int failedAttempts = 0;
private void btnlogin_Click_1(object sender, EventArgs e)
{
valid = validate();
if (!valid) {
//Increment the number of failed attempts
failedAttempts += 1;
//If equal to 3
if (failedAttempts == 3) {
//Just close this window
this.Close();
}
}
else
{
//the same code you were using...
}
}
}
}
您可以在程序中添加一个变量,然后增加它以限制登录的尝试次数。 要限制帐户的尝试次数,请添加一个表以将登录信息(包括无效尝试)存储到数据库中。 将该表链接到您的客户表。 尝试登录无效的客户帐户时,尝试增加无效尝试的次数,然后将其写回到登录表中。 成功登录后,您可以将无效尝试次数设置为0。
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