如何从不同的 button_click 访问一个 button_click 内的数组？

Question

When I click the "newRound" button, the program generates the Minor Arcana Deck and shuffles it via FisherYatesShuffle method.

public partial class MainWindow : Window
    {
     public MainWindow()
            {
                InitializeComponent();
            }
    
     private void newRound_Click(object sender, RoutedEventArgs e)
            {
                var minorArcanaDeck = new string[] {"Ace of Wands","Two of Wands", etc.};
                var rng = new Random();
                rng.Shuffle(minorArcanaDeck);
            }  
    }

static class FisherYatesShuffle
        {
            public static void Shuffle<T>(this Random rng, T[] array)
            {
                int n = array.Length;
                while (n > 1)
                {
                    int k = rng.Next(n--);
                    T temp = array[n];
                    array[n] = array[k];
                    array[k] = temp;
                }
            }
        }

In a different button (which is also within the partial class), I want to access this minorArcanaDeck Array, but I don't know how. How would I make this code below work, so that a textbox displays the value of the array when the "drawCard" button is clicked?

private void drawCard_Click(object sender, RoutedEventArgs e)
    {
        myText.Text = minorArcanaDeck[0];  
   
    }

Answer 1

You need to understand the difference between local variables and class variables(fields/properties)

You should define the array as a field, this way each (non-static) method is able to access it.

public partial class MainWindow : Window
{
    // fields
    private string[] _minorArcanaDeck = new string[] {"Ace of Wands","Two of Wands", etc.};
    private Random _rng = rand = new Random(Guid.NewGuid().GetHashCode());

    public MainWindow()
    {
        InitializeComponent();
    }

    private void newRound_Click(object sender, RoutedEventArgs e)
    {
        _rng.Shuffle(_minorArcanaDeck);
    }  
    
    private void drawCard_Click(object sender, RoutedEventArgs e)
    {
        myText.Text = _minorArcanaDeck[0];  
    }
}

static class FisherYatesShuffle
{
    public static void Shuffle<T>(this Random rng, T[] array)
    {
        int n = array.Length;
        while (n > 1)
        {
            int k = rng.Next(n--);
            T temp = array[n];
            array[n] = array[k];
            array[k] = temp;
        }
    }
}

In my case I use the _ prefix, so I have a clear naming convention. But it isn't required. By moving the Random out of the newRound_Click method and using a random seed, will generate better random numbers. (else you would always have the same random sequence)