Question

iam new to C#

i got some problem, i am create some picturebox in the Form1 through Form.cs[Design]

i want to accessing the picture box from Form1

so i have to create an object on other class to access Form1.picturebox1

but i can get it right, can some one help me

namespace RaceGame{
class Greyhound
{

    Form1 runner;

    public int StartingPosition = 13;
    public int RacetrackLength = 420;
    public PictureBox MyPictureBox = null;
    public int Location = 0;
    public Random Randomizer;

    public void Run()
    {

        runner.pictureDog1.Location = new Point(13, 100);
    }     
}

this is Form1

namespace RaceGame{public partial class Form1 : Form
{
    Greyhound racing = new Greyhound();
    public Form1()
    {
        InitializeComponent();
    }

    private void raceButton_Click(object sender, EventArgs e)
    {
        racing.Run();
    }



}

}

Answer 1

Based on the code you’ve provided, your Form1 or ‘runner’ isn’t being assigned.
You have two options –
1) make your runner public like so

public Form1 runner;

this will allow you to (in your form, not your class) assign the form to this property

public class Form1
{
        protected void Form1_Load(object sender, EventArgs e)
        {
              Greyhound gh = new Greyhound();
              gh.runner = this;//this line here
              //then you can call gh.Run()
        }
}

the other option is to use a constructor, like so –

class Greyhound
{

    Form1 runner;

    public int StartingPosition = 13;
    public int RacetrackLength = 420;
    public PictureBox MyPictureBox = null;
    public int Location = 0;
    public Random Randomizer;

    //here
    public Greyhound(Form1 form)
    {
        this.runner = form;
    }
    public void Run()
    {

        runner.pictureDog1.Location = new Point(13, 100);
    }     
}

this will pass the form into the greyhound class for you to access, then in your form code –

public class Form1
{
        protected void Form1_Load(object sender, EventArgs e)
        {
              Greyhound gh = new Greyhound(this);//pass the form as 'this'
              //then you can call gh.Run()
        }
}

EDIT:
based on the form code you gave –

namespace RaceGame
{
    public partial class Form1 : Form
    {
         Greyhound racing = new Greyhound();
         public Form1()
         {
            InitializeComponent();
         }

         private void raceButton_Click(object sender, EventArgs e)
         {
              racing.runner = this;//assign property here
              racing.Run();
         }
    }
}

and the Greyhound class

namespace RaceGame
{
    class Greyhound 
    {

        public Form1 runner;//make property public

        public int StartingPosition = 13;
        public int RacetrackLength = 420;
        public PictureBox MyPictureBox = null;
        public int Location = 0;
        public Random Randomizer;

        public void Run()
        {

            runner.pictureDog1.Location = new Point(13, 100);
        }      
    }
}