Question

I have a user control that has the following overridden event:

protected override void OnKeyDown(KeyEventArgs e)
{
    if (e.KeyCode == Keys.Left )
        DoSomething();
}

When I place the user control on my Main Form, this event is not fired.
How can I access this event from Parent form?

protected override void OnKeyDown(KeyEventArgs e)
{
    e.Handled = true;
    if (e.KeyCode == Keys.Left)
        Move(pt.X,pt.Y);//Move is a function within the usercontrol
    else if (e.KeyCode == Keys.Right)
        Move(pt.X,pt.Y);
   //other conditions
   e.Handled = false;
}

I need the parent to be notified on this event

Answer 1

If I understand correctly, you are trying to invoke the OnKeyDown method of the user control from within the parent form.
This is the main form class:

public class Form1 : Form
{
    private UserControl1 myControl;

    public Form1()
    {
        myControl = new UserControl1();
        Controls.Add(myControl);
    }

    protected override void OnKeyDown(KeyEventArgs e)
    {
        base.OnKeyDown(e);
        myControl.InvokeOnKeyDown(e);
    }
}

And this is the User Control:

public class UserControl1 : UserControl
{
    protected override void OnKeyDown(KeyEventArgs e)
    {
        base.OnKeyDown(e);
        MessageBox.Show("Key Down Fired!");
    }

    public void InvokeOnKeyDown(KeyEventArgs e)
    {
        OnKeyDown(e);
    }
}

Edit regarding arrow keys: the arrow keys are not normally considered to be input keys and therefore are not passed on to the key methods. To change this you must override the IsInputKey method as such:

 protected override bool IsInputKey(Keys e)
 {
     if (e == Keys.Up || e == Keys.Down ||
         e == Keys.Left || e == Keys.Right) return true;
     return base.IsInputKey(e);
 }