從另一個類C＃訪問變量

Question

因此，場景是用戶已經使用憑據登錄，並且當他們將商品添加到購物車時，我希望將全名從Account.cs提取到ProductGUI.cs

這是我嘗試過的方法，但是會提示出一個空的Console語句。

抱歉，如果我問一個重復的問題，但我需要幫助以弄清楚如何專門解決此問題。

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

您必須使Login-GUI和Product-GUI都知道您的Account實例。 最簡單（最丑陋，最不推薦）的方法是使其靜態：

class LoginGUI
{
    public static Account acc;

    [...]
}

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

    [...]
}

但是，確實，對單例模式有很好的了解。 依賴注入也可能會有所幫助。

Answer 2

您可以通過創建全名的靜態屬性來實現。 它們對於在程序中抽象全局數據很有用。