使用二进制文件的 C# Winforms 登录表单

Question

我目前正在开展一个学校项目，该项目将包含您经典的登录/注册表单。该项目要求我们包含一个二进制文件来“安全”存储每个用户的信息，例如用户名、密码等。

当新用户注册时，我成功地将其信息写入名为“users”的二进制文件，然后我成功地将其读回富文本框。 (这只是为了让我知道所有内容都被读回)。

当最后一个注册用户输入到表单的登录部分时，我也能够成功识别该用户，但我无法识别任何其他用户的信息。

我的注册代码(例如，当单击注册表按钮时)

private void btnRegister_Click(object sender, EventArgs e)
{
    //Try - Catch Statements
    //Try to set the forename

    try
    {
        newUser.Forename = txtForename.Text;
        errForename.Icon = Properties.Resources.CorrectIcon;
        errForename.SetError(txtForename, "OK");
    }

    // catch the exception error if one is raised and place the message
    //into the ErrorProvider

    catch (NewException exc)
    {
        errForename.SetError(txtForename, exc.MessageM);
    }

    //Try to set the surname
    try
    {
        newUser.Surname = txtSurname.Text;
        errSurname.Icon = Properties.Resources.CorrectIcon;
        errSurname.SetError(txtSurname, "OK");
    }

    // catch the exception error if one is raised and place the message
    //into the ErrorProvider

    catch (NewException exc)
    {
        errSurname.SetError(txtSurname, exc.MessageM);
    }

    //Try to set the password
    try
    {
        newUser.Password = txtPasswordR.Text;
        errPasswordR.Icon = Properties.Resources.CorrectIcon;
        errPasswordR.SetError(txtPasswordR, "OK");
    }

    // catch the exception error if one is raised and place the message
    //into the ErrorProvider

    catch (NewException exc)
    {
        errPasswordR.SetError(txtPasswordR, exc.MessageM);
    }    

    // These lines of code set the User class 

    if (newUser.Password != null )
    { 
        newUser.Forename = txtForename.Text;
        newUser.Surname = txtSurname.Text;
        newUser.Username = txtUsernameR.Text;
        newUser.Password = txtPasswordR.Text;   

        FileStream fileStream = new FileStream("../../Textfiles/users.bin", FileMode.Append);
        BinaryWriter binaryWriter = new BinaryWriter(fileStream);
        {
            binaryWriter.Write(newUser.Forename);
            binaryWriter.Write(newUser.Surname);
            binaryWriter.Write(newUser.Username);
            binaryWriter.Write(newUser.Password);

        }

        binaryWriter.Flush();
        binaryWriter.Close();
    }
}

我的从 Bin 文件读取的代码

public bool ReadFromBin(string a, string b)
{
    bool okFlag = false;

    FileStream fileStream = File.OpenRead("../../TextFiles/users.bin");
    BinaryReader binaryReader = new BinaryReader(fileStream);

    while (binaryReader.PeekChar() != -1)
    {
        newUser.Forename = binaryReader.ReadString();
        newUser.Surname = binaryReader.ReadString();
        newUser.Username = binaryReader.ReadString();
        newUser.Password = binaryReader.ReadString();


        if ((newUser.Username == a) && (newUser.Password == b))
            okFlag = true;
        else
            okFlag = false;
    }

    binaryReader.Close();
    return okFlag;
}

最后是非常简单的登录代码

private void btnLogIn_Click(object sender, EventArgs e)
{
    if(this.ReadFromBin(txtUsername.Text, txtPassword.Text) == false)
    {
        MessageBox.Show("Not registered!");
    }
    else
    {
        MessageBox.Show("Registered!");
        Game frm = new Game(newUser);
        frm.Show();
    }
}

我的理解是问题很可能出在 ReadFromBin 方法中包含的 while 循环中，我只是不确定如何修复它。谢谢!

Answer 1

我相信您的问题出在状况上。

您始终在测试用户是否是 (a,b)，并且只有当最后一个用户是 (a,b) 时您的代码才能工作。

您需要更改以下内容:

public bool ReadFromBin(string a, string b)
    {
        bool okFlag = false;

        FileStream fileStream = File.OpenRead("../../TextFiles/users.bin");
        BinaryReader binaryReader = new BinaryReader(fileStream);

        while (binaryReader.PeekChar() != -1)
        {
            newUser.Forename = binaryReader.ReadString();
            newUser.Surname = binaryReader.ReadString();
            newUser.Username = binaryReader.ReadString();
            newUser.Password = binaryReader.ReadString();


            if ((newUser.Username == a) && (newUser.Password == b))
              {
                 okFlag = true;
                 break;
              }
        }

        binaryReader.Close();
        return okFlag;


    }