C#: how do you refer to content in Program.cs in a form.cs?

Question

I am trying to place a value (from an object) in a variable and place it in a textbox in a form.

Here is the form code:

public Form1(Deck mainDeck)
    {
        InitializeComponent();
        int Val = mainDeck.ReturnCard(10);
        textBox1.Text = Val.ToString();
    }

mainDeck is an object in my Program.cs file

The problem line is this one: int Val = mainDeck.ReturnCard(10);

Oops, wrong error. This is the real one:

Error 1 The name 'mainDeck' does not exist in the current context C:\Users\Chris\Documents\Visual Studio 2008\Projects\Pcard\Pcard\Form1.cs 17 23 Pcard

Here is my Program.cs file:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace Pcard
{
    class Deck
    {
        public Deck()
        {
            // Assign standard deck to new deck object
            //   int j;
            for (int i = 0; i != currentDeck.Length; i++)
            {
                currentDeck[i] = originalCards[i];
            }
            // Fisher-Yates Shuffling Algorithim    ---   Do initial shuffle
            Random rnd = new Random();

            for (int k = currentDeck.Length - 1; k >= 0; k--)
            {
                int r = rnd.Next(0, k + 1);

                int tmp = currentDeck[k];
                currentDeck[k] = currentDeck[r];
                currentDeck[r] = tmp;
            }
        }
        public void Shuffle()
        {
            Random rnd = new Random();

            for (int k = currentDeck.Length - 1; k >= 0; k--)
            {
                int r = rnd.Next(0, k + 1);

                int tmp = currentDeck[k];
                currentDeck[k] = currentDeck[r];
                currentDeck[r] = tmp;
            }
        }
        public int[] ReturnDeck()
        {
            return currentDeck;
        }
        public int ReturnCard(int num)
        {
            return currentDeck[num];
        }

        public int[] originalCards = new int[54]
        {
            0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
            0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D,
            0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D,
            0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D,
            0x50, 0x51
        };
        private int[] currentDeck = new int[54];

    }
   public class Program
    {
        static void Main(string[] args)
        {
            // Create a Deck object
            Deck mainDeck = new Deck();
            Console.WriteLine("Here is the card array:");
            for (int index = 0; index != 54; index++)
            {
                string card = mainDeck.ReturnCard(index).ToString("x");
                Console.WriteLine("0x" + card);
            }
            //Return 10th Card
            int PickCard = mainDeck.ReturnCard(10);
            Console.WriteLine("Here is the 10th Card");
            Console.WriteLine("0x" + PickCard);
            //Shuffle
            mainDeck.Shuffle();
            Console.WriteLine("Shuffling..");
            PickCard = mainDeck.ReturnCard(10);
            Console.WriteLine("Here is the 10th card now: 0x" + PickCard);
            Application.Run(new Form1(maindeck));
        }
    }
}

Edit: Okay, I am passing mainDeck to the Form, but I am now getting a different error: Error 1 Inconsistent accessibility: parameter type 'Pcard.Deck' is less accessible than method 'Pcard.Form1.Form1(Pcard.Deck)' C:\Users\Chris\Documents\Visual Studio 2008\Projects\Pcard\Pcard\Form1.cs 14 16 Pcard

Edit: Edit: Alright, I now have this working, but I ran into a related problem, so I would rather put it here than in a new question.

Passing mainDeck to the Form1 works fine, but what about if I want to have a button click call a method in this object. I tried passing mainDeck like this:

 private void button1_Click(object sender, Deck mainDeck, EventArgs e)
        {
            mainDeck.Shuffle();
        }

I get this error:
Error 1 No overload for 'button1_Click' matches delegate 'System.EventHandler' C:\Users\Chris\Documents\Visual Studio 2008\Projects\Pcard\Pcard\Form1.Designer.cs 51 35 Pcard

GRR!

Answer 1

The easiest way would be to change the form's constructor to pass in mainDeck.

public Form1(Deck mainDeck)
{
    InitializeComponent();
    int Val = mainDeck.ReturnCard(10);
    textBox1.Text = Val.ToString();
}

If you needed to refer to it in other parts of your forms code, you could keep a private member variable lying around ...

private Deck _mainDeck;

public Form1(Deck mainDeck)
{
    InitializeComponent();
    _mainDeck = mainDeck;
    int Val = _mainDeck.ReturnCard(10);
    textBox1.Text = Val.ToString();
    }
}

private void SomeOtherMethod()
{
    int blah = _mainDeck.Blah();
}

And then in your Program.cs file ...

Application.Run(new Form1(mainDeck));

Edit: In response to your new error involving the accessibility of the Deck class, it is because your Deck class is not public. Add the public keyword to the class declaration, so:

namespace Pcard
{
    public class Deck
    {
        // and so on ... 

Note that it might be cleaner to keep your Deck class in a separate .cs file, such as Deck.cs.