Question

我在这个节目中工作了3个小时，但我不知道我在哪里做错了。如果你能帮助我真的很感激。问题是当我输入密码时。即使我输入了正确的密码它也是错误的密码，它不允许我再次重试。该程序假设允许用户尝试3次如果用户输错密码第三次该程序必须关闭。

public partial class UserAndPin : Window
{
    public UserAndPin()
    {
        InitializeComponent();
    }

    private void btnOK_Click(object sender, RoutedEventArgs e)
    {
        try
        {
            StreamReader sr = new StreamReader("Customer.txt");

            short attempts = 0;
            string line;

            while ((line = sr.ReadLine()) != null)
            {
                string[] lineArray = line.Split(';');
                if (lineArray[0] == txtName.Text & lineArray[1] == pbPassword.Password)
                {
                    MainWindow mainWindow = new MainWindow();
                    this.Hide();
                    mainWindow.ShowDialog();
                    //return;
                }
                else
                {
                    attempts++;
                    if (attempts < 3)
                    {
                        MessageBox.Show("The NAME or PIN is incorect, you have " + (3 - attempts) + " attemps more");                                                    
                    }
                    if (attempts == 3)
                    {
                        MessageBox.Show("Please try again later");
                        this.Close();
                    }                        
                }                    
            }
            sr.Close();
        }
        catch (Exception error)
        {
            MessageBox.Show(error.Message);
        }
    }
}

}

Answer 1

由于您每次点击按钮时都会在short attempts = 0;内声明btnOK_Click，因此attempts会0为public partial class UserAndPin : Window { short attempts; public UserAndPin() { InitializeComponent(); attempts = 0; }，而您希望每次增加1 {1}}用户单击按钮，因此您需要将其全局声明为

attempts++;

attempt应低于while循环，因为如果文件中有10个用户信息，则每次条件不匹配时它将添加或增加Logical AND operator。

现在，如果用户名和密码与您正在阅读的文件不匹配。如果用户信息位于第10个位置或行，它显然不匹配，它将为您提供9次消息框。另一个问题是&&它是&而不是public partial class UserAndPin : Window { short attempts; public UserAndPin() { InitializeComponent(); attempts = 0; } private void btnOK_Click(object sender, RoutedEventArgs e) { try { StreamReader sr = new StreamReader("Customer.txt"); string line; while ((line = sr.ReadLine()) != null) { string[] lineArray = line.Split(';'); if (lineArray[0] == txtName.Text && lineArray[1] == pbPassword.Password) { MainWindow mainWindow = new MainWindow(); this.Hide(); mainWindow.ShowDialog(); //return; } } sr.Close(); if (attempts < 3) { MessageBox.Show("The NAME or PIN is incorect, you have " + (3 - attempts) + " attemps more"); } else { MessageBox.Show("Please try again later"); this.Close(); } attempts++; //Since user has attempted it. } catch (Exception error) { MessageBox.Show(error.Message); } } }而且它会匹配所以正确的方法应该是

SELECT * FROM (

SELECT DISTINCT cases.caseid, cases.img, casetypes.casetypeid, cases.cost
FROM cases, casetypes
WHERE cases.caseid =  casetypes.caseid AND casetypes.mastercaseid = $mastercaseid
LIMIT $lastrow, $perPage
) x

ORDER BY RAND()

Answer 2

你应该开始尝试＆＃39;每次认证成功。或3小时内超过3次。

如果您在2次成功登录，则尝试＆＃39;应该是0。

如果项目拒绝您登录的时间超过3小时，则“尝试”会尝试＆＃39;也应该设置为0。

Answer 3

首先，您需要阅读文件以获取所有用户名和密码。理想情况下，您只能在构造函数中执行此操作一次。

然后，您需要将计数器增加一个。此计数器需要在click事件处理程序之外声明，如其他答案中所述。

最后，您可以检查输入的用户/密码是否与文件中的一个匹配。如果是，您可以打开表单。如果没有，则根据用户是否已达到第三次尝试，显示其中一个消息框。

public partial class UserAndPin : Window
{
    short attempts;

    public UserAndPin()
    {
        InitializeComponent();
        attempts = 0;
    }

    private void btnOK_Click(object sender, RoutedEventArgs e)
    {
        try
        {   
            var users = File.ReadAllLines("Customer.txt")
                .Select(line => new { login = line[0], password = line[1] })
                .ToList();

            attempts++;

            if (users.Any(user => user.login == txtName.Text && user.password == pbPassword.Password))
            {
                MainWindow mainWindow = new MainWindow();
                this.Hide();
                mainWindow.ShowDialog();
                return;
            }
            else
            {
                if (attempts < 3)
                {
                    MessageBox.Show("The NAME or PIN is incorect, you have " + (3 - attempts) + " attemps more");
                }
                if (attempts >= 3)
                {
                    MessageBox.Show("Please try again later");
                    this.Close();
                }
            }
        }
        catch (Exception error)
        {
            MessageBox.Show(error.Message);
        }
    }
}

Answer 4

Dictionary<string, string> loginInfo;
short attempts = 0;

public UserAndPin()
{
    InitializeComponent();

    // Load the file to the dictionary
    loginInfo = File.ReadAllLines("Customer.txt")
        .Select(i => i.Split(';')) // Lines format: Username;Password
        .ToDictionary(i => i[0].ToLower(), i => i[1]);  // Username is the key of the dictionary

}

private void btnOK_Click(object sender, RoutedEventArgs e)
{    
    var userId = txtName.Text.ToLower(); // Username ignore case
    var password = pbPassword.Password;

    if (loginInfo.ContainsKey(userId) && loginInfo[userId] == password)
    {
        // login success, show main window
        MainWindow mainWindow = new MainWindow();
        this.Hide();
        mainWindow.ShowDialog();
        return;
    }

    // login fail, increment the count only
    attempt++;

    if (attempts < 3)
    {
        MessageBox.Show("The NAME or PIN is incorect, you have " + (3 - attempts) + " attemps more");                                                    
    }
    if (attempts == 3)
    {
        MessageBox.Show("Please try again later");
        this.Close();
    }   

}

如何让用户在c＃中输入密码3次？

4 个答案: