Child mdi window in child mdi window in .Net 4 Forms?

Question

.NET

Tell me how to create a child mdi window in a child mdi window in .Net 4 Forms?
Wrote a winforms application with the following code:
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
this.IsMdiContainer = true;
f = new Form2();
f.MdiParent = this;
f.Show();
f.Location = newPoint(0, 20);
f.IsMdiContainer = true;
f1 = new Form3();
f1.MdiParent = f;
f1.Show();
}
After launch, the main window opens with one child mdi-window (Form2), but there is no second child window (Form3) in it.
Please tell me what is the problem and how to solve it. Or how to get around.

Answer 1

This confuses the user, so this out of the box is not possible. For the same reason, I recommend not to look for workarounds, but to reconsider the design in principle. It is desirable in general towards sdi.
And finally, it goes to wpf - 2012 in the yard.

Answer 2

I understand that this is a relic of the past, but for solving some problems it is very useful. In particular, I'm developing a graphical simulation environment that sometimes needs to display a graphic space inside another graphic space (like a window in a house). And nesting should be arbitrary. Therefore, it is very important for me to solve this problem.