Static control, multiple references

[.pd.]

Hello,

If I have a static control and 2 forms, each of which references the
static. When I return from the 2nd and go back to the first, the
reference to static control appears to have been removed altogether. It
disappears from the first form.

If you run the following example, click "DerivedFor m1" then close it
(ok). Then click "DerivedFor m2" and close that.

When you click DerivedForm1 again, the "Something" button has vanished.

I tested this on .NETCF. Is it a problem? If not, would someone explain
why this happens?

Cheers,
..pd.

using System;
using System.Drawing;
using System.Collecti ons;
using System.Windows. Forms;
using System.Data;

namespace ToggleSubscribe r
{
public class Form1 : System.Windows. Forms.Form
{
DerivedForm1 df1;
DerivedForm2 df2;
public static Button the_button;
public Form1()
{
the_button = new Button();
MinimizeBox = false;
Button b1 = new Button();
b1.Text = "DerivedFor m1";
b1.Size = new Size(100, 20);
b1.Location = new Point(60, 40);
Button b2 = new Button();
b2.Size = new Size(100, 20);
b2.Text = "DerivedFor m2";
b2.Location = new Point(60, 80);

b1.Click += new EventHandler(b1 _Click);
b2.Click += new EventHandler(b2 _Click);

Controls.Add(b1 );
Controls.Add(b2 );
}
protected override void Dispose( bool disposing )
{
base.Dispose( disposing );
}
static void Main()
{
Application.Run (new Form1());
}

private void b1_Click(object sender, EventArgs e)
{
if (df1 == null)
df1 = new DerivedForm1(th e_button);
df1.Show();
}

private void b2_Click(object sender, EventArgs e)
{
if (df2 == null)
df2 = new DerivedForm2(th e_button);
df2.Show();
}
}

public class BaseForm : Form
{
public delegate void OnSomethingHapp ens(object sender,
EventArgs e);
public event OnSomethingHapp ens SomethingHappen ed;
private Button b;

public BaseForm(Button btn)
{
MinimizeBox = false;
b = btn;
b.Location = new Point(60, 60);
b.Text = "Something" ;
b.Click += new EventHandler(b_ Click);
Controls.Add(b) ;
}

private void b_Click(object sender, EventArgs e)
{
if (SomethingHappe ned != null)
SomethingHappen ed(sender, e);
}
}

public class DerivedForm1 : BaseForm
{
BaseForm.OnSome thingHappens del;
public DerivedForm1(Bu tton btn) : base(btn)
{
del = new OnSomethingHapp ens(DerivedForm 1
_SomethingHappe ned);
SomethingHappen ed += del;

Closing += new System.Componen tModel.CancelEv entHandler
(DerivedForm1_C losing);
}

private void DerivedForm1_So methingHappened (object sender,
EventArgs e)
{
MessageBox.Show ("Something happened in DerivedForm1");
}

private void DerivedForm1_Cl osing(object sender,
System.Componen tModel.CancelEv entArgs e)
{
SomethingHappen ed -= del;
this.Visible = false;
e.Cancel = true;
}
}
public class DerivedForm2 : BaseForm
{
BaseForm.OnSome thingHappens del;
public DerivedForm2(Bu tton btn) : base(btn)
{
del = new OnSomethingHapp ens(DerivedForm 1
_SomethingHappe ned);
SomethingHappen ed += del;

Closing += new System.Componen tModel.CancelEv entHandler
(DerivedForm1_C losing);
}

private void DerivedForm1_So methingHappened (object sender,
EventArgs e)
{
MessageBox.Show ("Something happened in DerivedForm2");
}

private void DerivedForm1_Cl osing(object sender,
System.Componen tModel.CancelEv entArgs e)
{
SomethingHappen ed -= del;
e.Cancel = true;
this.Visible = false;
}
}
}