C#

public class Program
{
    // (2)
    public static void Main()
    {
        A a = new A();
        a.DoStuff();
    }
}
 
public class A
{
    // (1)
    private B b;
    private C c;
 
    public A()
    {
        // (3)
        this.b = new B(this);
        this.c = new C(this);
    }
 
    public void DoStuff()
    {
        c.mc();
    }
 
    // (6) This allows C to call A without knowing about B 
    // (7) i.e. information hiding, which is a good OO concept
    public void CallMB()
    {
        this.b.mb();
    }
}
 
public class B
{
    // (4)
    private A a;
 
    // (5)
    public B(A a)
    {
        this.a = a;
    }
  
    public void mb()
    {
        Console.WriteLine("I'm in class B");
        Console.Read();
    }
}
 
public class C
{
    // (4)
    private A a;
 
    // (5)
    public C(A a)
    {
        this.a = a;
    }
 
    public void mc()
    {
        // (6) 
        this.a.CallMB();
    }
}

MyForm B = new MyForm();<br />
B.MyProperty = variablefromA;<br />
B.showDialog();

private int _xGrid=0;<br />
private int _yGrid=0;

private void dataGrid_MouseMove(sende , even e)<br />
   {<br />
     _xGrid=e.X;<br />
     _yGrid=e.Y;<br />
   }