从另一个类C＃访问变量

Question

So the scenario is that a user has already logged in with the credentials, and when they have added an item to a cart, i want the full name to be taken from Account.cs to ProductGUI.cs

This is the method that I've tried, but it prompts out an empty Console statement.

Sorry if I'm asking a duplicate question, but i need help to figure out how to specifically solve this problem.

Account.cs

    private string fullname;
    private string username;
    private string email;
    private string password;

    public Account(string fullname, string username, string email, string password)
    {
        this.fullname = fullname;
        this.username = username;
        this.email = email;
        this.password = password;
    }

    public string Fullname
    {
        get
        {
            return fullname;
        }
        set
        {
            fullname = value;
        }
    }

ProductGUI.cs

private void addToCartButton_Click(object sender, EventArgs e)
    {
        // I believe I'm creating a new account based another question, but how do i pass the information without creating a new account.
        Account a = new Account();
        Console.WriteLine(a.Fullname);
    }

LoginGUI.cs

private void signinButton_Click(object sender, EventArgs e)
    {
        bool temp = false;
        foreach (DataRow row in dt.Rows)
        {
            if (row["Username"].ToString() == usernameTextbox.Text && row["Password"].ToString() == passwordTextbox.Text)
            {
                string fullname = row["Fullname"].ToString();
                string username = row["Username"].ToString();
                string email = row["Email"].ToString();
                string password = row["Password"].ToString();

                // I've saved the information into account.
                acc = new Account(fullname, username, email, password);
                temp = true;
            }
        }
        if (temp)
        {
            MessageBox.Show("Welcome to Anime Fanatic.\n Enjoy your stay!");
            this.Hide();
            mainPageGUI mainPage = new mainPageGUI();
            mainPage.ShowDialog();
        }
        else
        {
            MessageBox.Show("You have entered an incorrect Username or Password.\n Please try again!");
        }
    }

Answer 1

You have to make your Account instance known to both your Login-GUI and your Product-GUI. The easiest (and most ugly and most not recommended) way to do this, is to make it static:

class LoginGUI
{
    public static Account acc;

    [...]
}

class ProductGUI
{
    private void addToCartButton_Click(object sender, EventArgs e)
    {
        Console.WriteLine(LoginGUI.acc.Fullname);
    }

    [...]
}

But really, have a good read about singleton pattern . And dependency injection might help, too.

Answer 2

You can achieve this by creating static property of fullname. They are useful for abstracting global data in programs.