获取随机卡并更改标签

Question

I'm just fooling around in Windows Forms and wish to click a button and then give a player 2 random cards, but when I click the button the label is empty. How do i pass the value to the string?

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void DealTheCardsButton_Click(object sender, EventArgs e)
    {
        TheCards theCards = new TheCards();
        CardOneLabel.Text = theCards.card1;
    }
}

public class TheCards
{
    public TheCards()
    {
        Cards = new List<string>();
        Cards.Add("1");
        Cards.Add("2");
        Cards.Add("3");
        Cards.Add("4");
    }

    public List<string> Cards { get; set; }

    public string card1;
    public string card2;

    public string cardTest = "hej";

    public void GiveTwoRandomCardsFromCardsList()
    {
        Random random = new Random();
        int slumptal = random.Next(0, 4);
        card1 = Cards[1];

        bool flag = false;
        while (!flag)
        {
            Random random2 = new Random();
            int slumptal2 = random2.Next(0, 4);

            if (slumptal != slumptal2)
            {
                card2 = Cards[slumptal2];
                flag = true;
            }
        }
    }
}

If I call to change the CardOneLabel.Text to a string with a hardcoded value in it it works. It seems like the randomizing doesn't change the value of string card1 and string card2 . As it is now, when I click on the button the label changes its value to nothing (empty).

How can i change the label value to a random card value?

Answer 1

But when I click the button the label is empty. How do i pass the value to the string?

When you try to assign the value

 CardOneLabel.Text = theCards.card1;

The constructor of that class TheCards is not initiating the card1 variable to anything, you are retrieving an empty string.

The constructor below, is adding to the list Cards but nothing else is taking place.. Do you have additional code your not showing?

public TheCards()
{
    Cards = new List<string>();
    Cards.Add("1");
    Cards.Add("2");
    Cards.Add("3");
    Cards.Add("4");
}

Your CardOneLabel is empty when you press the button because you are literally reading an empty string. Try calling your GiveTwoRandomCardsFromCardsList() method before assigning.

Answer 2

You never call the GiveTwoRandomCardsFromCardsList method. Try this:

private void DealTheCardsButton_Click(object sender, EventArgs e)
{
    TheCards theCards = new TheCards();
    theCards.GiveTwoRandomCardsFromCardsList();

    CardOneLabel.Text = theCards.card1;
}

By the way, don't create a new Random object for every random number you require. This might even give you the same random number due to how the pseudo-random number generator depends on the current time. Just use the same Random instance over and over again. It will give you a new random number every time.

Also, you will sometimes get the same card twice. I'll leave it to the OP to figure out how to always get two different cards, if that's the idea.